What do you run, and what do you want to run?

75 current, is a 727, stock D20, with 3.54's
Should be: 727 Dana 300 w/4:1 Tera, and 4.10's

74 current (even though it does not run) T18, D20, 3.73's.
Will be T98 (6.4:1 Granny), D20 w/Tera 3.15 kit, and 4.10's

I've also considered the Mr. Scout box which would work with both rigs, and give me the desired low range.

Joe <IMG SRC="smilies/smokin.gif" border="0">

Originally posted by jdjanda:
[QB]What do you run, and what do you want to run? QB]


75 stock 727/d20 3.73 with 33'
I've putting some 3/4 tons with 4.56 and 35's on in the next month and would also like to get the Tera low for the D20. Was going to get the lower ttrany gears but just had it rebuilt 3k ago so I can't justify spending money on that.

Brandon
<IMG SRC="smilies/grinpimp.gif" border="0">

current 3.73 w/ 30"tires. new axles are 4.10's but want 5.13's <IMG SRC="smilies/biggrin.gif" border="0">

Currently:

SM465 to a D20
6.55? x 2.03? x 4.10's =High Speed Rock crawling or a burnt clutch or 54.5 to 1.

However, I picked up another 465 yesterday and I am getting ready to buy the 465 to 300 adaptor. From there, I may go Atlas or 4 to 1 D300. Also, I am switching to 35 spline axles in the 60 and upgrading to 4.56's at the same time.

So it would look like this:

6.55 x 4.0 x 4.56 =119.5
or
6.55 x 4.3 x 4.56 =128.4

Either set up would definitly help slow me down...

<IMG SRC="smilies/crybaby2.gif" border="0"> Gotta love the 465/205 combo for its strength but damn someone needs to make a kit for that case! klune is about the only way to go w/ that setup. Doubler is a major PITA because you need the 203 that was mated to the 465 (made for about 1/4 of a year) and the adapter (rarer than the white whale!) or its huge $$$ aftermarket <IMG SRC="smilies/crybaby2.gif" border="0"> life sucks <IMG SRC="smilies/biggrin.gif" border="0">

But 6.55 x 1.96 x 4.10 = 52.63 isnt too bad but...

6.55 x 4 x 1.96 x 4.10 (or 5.13) = 210.54
(or 263.43) <IMG SRC="smilies/eek.gif" border="0"> holy crawl batman! not too sure on the math did it quick...

[ 10-09-2001: Message edited by: YDB ]

Gearing...uh yeah that's not too hot.

ALL STOCK 727/D20/Stock D44 w/trashlock gears I think 3.09's????

I think my current set-up nets me a 35:1 crawl ratio. I haven't really added it up with the stock gears yet, I've been too busy dreaming of my ultimate set-up.

Anyway I'm looking forward to a few years from now when I have 4.56 gears in my 3/4- ton axles and a 500ci Caddy, Then I'll see if I need an atlas or Tera Low gears for the D20. I'm afraid the caddy engine would shatter that though

Originally posted by Scout Dude:
<STRONG>Currently:

SM465 to a D20
6.55? x 2.03? x 4.10's =High Speed Rock crawling or a burnt clutch or 54.5 to 1.

However, I picked up another 465 yesterday and I am getting ready to buy the 465 to 300 adaptor. From there, I may go Atlas or 4 to 1 D300. Also, I am switching to 35 spline axles in the 60 and upgrading to 4.56's at the same time.

So it would look like this:

6.55 x 4.0 x 4.56 =119.5
or
6.55 x 4.3 x 4.56 =128.4

Either set up would definitly help slow me down...</STRONG>

Yes but look at cost... 2K for the atlas or ~ 300 for the d300 + 700 for the gears... 1K vs 2K + cool factor <IMG SRC="smilies/glasses.gif" border="0"> but you could add in the upgraded outputs for the d300 and be somewhat close to cost not sure on strength...

Originally posted by Cliffhanger:
<STRONG>
I think my current set-up nets me a 35:1 crawl ratio. </STRONG>

Yes but its said the torque multiplication in the auto theoretically doubles the crawl...

Originally posted by YDB:
<STRONG>Yes but look at cost... 2K for the atlas or ~ 300 for the d300 + 700 for the gears... 1K vs 2K + cool factor <IMG SRC="smilies/glasses.gif" border="0"> but you could add in the upgraded outputs for the d300 and be somewhat close to cost not sure on strength...</STRONG>

I figure it like this:
Money does not matter--My Scout is paid for and I am not selling it. I'll never make what I put in to it anyway. However, if I am out in the mountains somewhere and I am broke because I decided to go "the cheaper way" I'm gonna be pissed <IMG SRC="smilies/pissed.gif" border="0">. 2K for a brand new t-case that is set up for the v-8 that I already have doesn't seem too bad. If I go, D300, I am putting in the tailshaft kit before it breaks. Sure the D300 is still marginally (sp?) cheaper even with the tailshaft kit but the case could still be stressed and could break on me...Also, if I go Atlas, I get 4.3 to 1 <IMG SRC="smilies/biggrin.gif" border="0">

Originally posted by jdjanda:
<STRONG>What do you run, and what do you want to run?
</STRONG>

Alright...

'Tigger' - currently a wide T19 and Dana 20 with 4.09s and 33s.
Sooner-than-later it'll have a 2.46:1 Dana 20
Later than sooner, 4.56 gears and 36s.

Crawl today: 51:1, tomorrow 63.5:1, down the road, 71:1

51:1 was slow enough to get 3rd place in the slow-obstacle at NWBRU in 2000.

"Little Devil" - 727/D20/4.88s and 31" tires.

Crawl of almost 24:1.

Sometimes, it's a little too low.. I need a 4bbl intake to get faster times in the 100-yard drags.. I'm running out of RPM (about 5500rpm) before the end of the drag strip. <IMG SRC="smilies/biggrin.gif" border="0">

BUGM - '72 T'all - 2.45 727, NP205, 3.73 gears, and 33s. 18.2:1! Good 'nuff for snow wheelin', and a good setup for a daily driver with a 392 under the hood. If I wheel it more, I'd like to stick with 3.73, or go 4.09s with the 33s, and install a SII 727 with a married Dana 20 for a crawl closer to 40:1

200 T'ette - T98, no t'case, and 4.30 gears with 31s for 27:1 (damn, that's lower than the Travelall that has a t'case!).

I'd like to get my hands on the 3spd brownie my buddy is probably not going to use.. to get my gearing UP for the highway, but a lower gear wouldn't hurt at times, either..

Eventually it'll get a transfer case, too. They don't make rotors for the IFS coil front.. so a live axle and leaf springs IS in it's future..

Wait, there's more.

My '72 SII, when it lives again, will probably be 304/345, close T19, Dana 20, 3.73/4.09, and 33s for every day use. About 30:1

No idea what gears are in the '74 SII.. heck, I haven't even looked to see if it's a 304 or a 345, but it's an auto, Dana 20, and 235/75s so it doesn't really matter what gears it has. <IMG SRC="smilies/wink.gif" border="0">

GF's 68 800.. 304/closeT19/D20/4.27s with 31s for 34:1

As far as the plan goes, it'll probably be 304/closeT19/D20/4.09/33s when we get there.. which'll be after she starts wheelin' it and breaks the Dana 30 front, or just around town and she strips the keys from the two-piece rear '44 from hammering the skinny pedal.. then some 4.09 SII 44s go under.

The usual

V-8, 727, D20, 3.54 gears in the diffs, and 33 inch tires.

I have pretty much decided to go with Mr. Scout Crawler box. Easy, strong, keep my highway gears, but get plenty low for the tough stuff.

Swapping to lower gears in my diffs would cost almost as much as the crawler box because I would have to replace both my lockright and front LS (Still very new and tight). I would not set up my own gears, so you have to add in that expense. Plus, my highway speed would suffer with the lower diff gears.

So, I am saving, or waiting for a nice big bonus, then I will be going the bolt in route. <IMG SRC="smilies/biggrin.gif" border="0">

Patrick

Originally posted by Hooper:
<STRONG>The usual

V-8, 727, D20, 3.54 gears in the diffs, and 33 inch tires.

I have pretty much decided to go with Mr. Scout Crawler box. Easy, strong, keep my highway gears, but get plenty low for the tough stuff.

Swapping to lower gears in my diffs would cost almost as much as the crawler box because I would have to replace both my lockright and front LS (Still very new and tight). I would not set up my own gears, so you have to add in that expense. Plus, my highway speed would suffer with the lower diff gears.

So, I am saving, or waiting for a nice big bonus, then I will be going the bolt in route. <IMG SRC="smilies/biggrin.gif" border="0">

Patrick</STRONG>

Seeing as how I don't have much of a Scout anymore, I don't keep up on all of the latest stuff available...With that in mind:
What in the hell is a "Mr Scout Crawler box"?

Originally posted by Hooper:
<STRONG>The usual

Swapping to lower gears in my diffs would cost almost as much as the crawler box because I would have to replace both my lockright and front LS (Still very new and tight). I would not set up my own gears</STRONG>

I don't think the Lockright for a 3.73-taller and a 3.92-lower is different. I'm pretty sure they're the same part number since the spider gears don't change, either.

You'd only need to replace the Trashlok in the front with something better. Ideally, move the LR up front, put a Detroit in the back.. there ya go! <IMG SRC="smilies/biggrin.gif" border="0">

Highway speeds? COME AWWWN, Pat. By the time you get the dough for the Mr.Scout crawler box you'll be lookin' at buyin' a crewcab and car trailer. <IMG SRC="smilies/biggrin.gif" border="0"> <IMG SRC="smilies/biggrin.gif" border="0"> <IMG SRC="smilies/thefinger.gif" border="0">

<IMG SRC="smilies/laughing.gif" border="0">

Originally posted by Scout Dude:
<STRONG>Seeing as how I don't have much of a Scout anymore, I don't keep up on all of the latest stuff available...With that in mind:
What in the hell is a "Mr Scout Crawler box"?</STRONG>

Essentially, a Dana 20 in a custom 'case. It has no front output.

It mates between your transmission and Dana 20 (or SII 300).

The nice part is it will use your standard bullgear off the transmission - so it'll work with a 727. The OUTPUT side of the crawler box looks like a 4spd and takes a 4spd bullgear - so you can use the 2:1 standard geared Crawler box behind your 727, then use a standard Dana 20 (2:1), 300 (2.62:1), or a Bronco gear equipped Dana 20 (2.21 or 2.46:1) OR a Tera geared Dana 20 (3.15) or 300 (4:1).

Without the 2:1 crawler box, you can't use ANY of the alternate gearing solutions for the Dana 20 or 300 behind a 727. (unless you happened to get one of the very very few custom bullgears..)

Then again, with a 727, I'd be really tempted to go with the Klune setup and a Jeep 300. <IMG SRC="smilies/biggrin.gif" border="0">

Originally posted by Hooper:
<STRONG>Swapping to lower gears in my diffs would cost almost as much as the crawler box because I would have to replace both my lockright and front LS </STRONG>

Just for your information, the Lock-Right will work in either series of open carrier, so your old one will still work fine. In fact I did this very thing when I switched mine from my stock 3.54's to my new 4.09's.

As to the gear topic:
I'm at 4.09 x 6.32 (T-19) x 2.47 (D20/EBD20/D18)= 64:1 with 33's.

I'd love to be lower, to around 90 or 100:1. I had been once with a 4:1 D300, but after breaking one set of gears, I decided not to run them any longer. Was leary about the D20 TeraLow too, so went with the Bronco D20/D18 gear swap and just live with it.

I have a GM NP205 that could be mated to a Klune-V which could be mounted to my T-19 for some serious slowness, but I think I'll save that setup for my next project.

Originally posted by Scout Dude:
<STRONG>What in the hell is a "Mr Scout Crawler box"?</STRONG>

The Crawler box is a second box between the tranny and t-case. Imagine a Dana 20 with only the low gears that bolts between the tranny and t-case. You can use stock Dana 20 gears, Bronco gears, Tera, and Jack O'Brien gears. The box has a D20 pattern front and rear allowing a bolt in design, add a cross member and new drive shafts and you're ready to go. Should also work for the Heep crowd with D20's. I thing the price is around $1,500 with stock D20 gears. And it will work with the Scout 727.

Joe <IMG SRC="smilies/smokin.gif" border="0">

Originally posted by Az Scout:
<STRONG>Tera low for the D20.</STRONG>

Not gonna work. No Tera kit for the Scout 727 autos. If you want to use a Tera kit you have to run a manual, or swap in a Dana 300.

Joe <IMG SRC="smilies/smokin.gif" border="0">

Originally posted by tsm1mt:
<STRONG>I don't think the Lockright for a 3.73-taller and a 3.92-lower is different. I'm pretty sure they're the same part number since the spider gears don't change, either.

You'd only need to replace the Trashlok in the front with something better. Ideally, move the LR up front, put a Detroit in the back.. there ya go! <IMG SRC="smilies/biggrin.gif" border="0">

Highway speeds? COME AWWWN, Pat. By the time you get the dough for the Mr.Scout crawler box you'll be lookin' at buyin' a crewcab and car trailer. <IMG SRC="smilies/biggrin.gif" border="0"> <IMG SRC="smilies/biggrin.gif" border="0"> <IMG SRC="smilies/thefinger.gif" border="0">

<IMG SRC="smilies/laughing.gif" border="0"></STRONG>

Yep. 3.73 and taller is same lockright. Problem is, I have 3.54 gears.

Hopefully, by next summer I will have the crawler box in.

Crawler box is like Klune V except that not as many gears. Pretty much just a doubler, or tripler, depending on the gears you have them put in it. It is a direct bolt on though. It bolts between your tranny and D20. No muss, no fuss. Shorten your rear driveline, lengthen the front. Also helps if you are putting a CV joint in. helps front driveline angles also. you get throughput, or engaged. Either cable actuated, or shifter actuated. But, pretty spendy at around $1500 or so.

Originally posted by jdjanda:
<STRONG>Not gonna work. No Tera kit for the Scout 727 autos. If you want to use a Tera kit you have to run a manual, or swap in a Dana 300.

Joe <IMG SRC="smilies/smokin.gif" border="0"></STRONG>


Atlas it is then.. Thanks for solving that dilema for me <IMG SRC="smilies/biggrin.gif" border="0">

Originally posted by Hooper:
<STRONG>Yep. 3.73 and taller is same lockright. Problem is, I have 3.54 gears.
</STRONG>

Hmmm.. re-read - <STRONG>I don't think the Lockright for a 3.73-taller and a 3.92-lower is different</STRONG>

That is supposed to say, "The same Lockright part # for 2.72-3.73 as it is for 3.92-5.38"

aka, you don't have to replace your LR. Unless, of course, go go with a 60. <IMG SRC="smilies/biggrin.gif" border="0">

<STRONG>
Crawler box is like Klune V except that not as many gears. Pretty much just a doubler, or tripler, depending on the gears you have them put in it. It is a direct bolt on though. It bolts between your tranny and D20. No muss, no fuss. Shorten your rear driveline, lengthen the front. Also helps if you are putting a CV joint in. helps front driveline angles also. you get throughput, or engaged. Either cable actuated, or shifter actuated. But, pretty spendy at around $1500 or so.</STRONG>

I thought it was $1800 for the Crawler.. but I'd be happy to be wrong. ;-)

Klune is 2.72 or 4:1 IIRC. And it bolts in with no muss, no fuss with the right collection of factory parts and lets you use the cheaper Jeep 300 for an even lower-low.. like Rick runs.

Originally posted by YDB:
<STRONG>Yes but its said the torque multiplication in the auto theoretically doubles the crawl...</STRONG>


I'm pretty sure that is with the Torqe converter theory figured in.

let's see..... 2.5(tranny 1st) x 2(torque conv) x 2(X-fer low) x 3.09(rear end) = 30.9

IS that math correct????

Originally posted by Cliffhanger:
<STRONG>
Atlas it is then.. Thanks for solving that dilema for me <IMG SRC="smilies/biggrin.gif" border="0"></STRONG>

of course, the Atlas will only work if you convert your 727 over to the round SAE/Jeep-300 bolt pattern with Dodge parts..

At which point you can run the Tera 4-1 for a 300, a Jeep 300, an Atlas, a Klune-V, or...

Could also go with the Dodge NP203 adapter, an NP203 reduction box, and an NP205 if you wanted BEEF..

Then again, *I* think that just makes the weak link the adapter or the aluminum transmission case.. and it sucks to break the trans case. <IMG SRC="smilies/biggrin.gif" border="0">

Originally posted by Cliffhanger:
<STRONG>
Atlas it is then.. Thanks for solving that dilema for me <IMG SRC="smilies/biggrin.gif" border="0"></STRONG>

Just looked over your website. Too Bad you're in Nebraska, I could solve you tub dilema also.

Joe <IMG SRC="smilies/smokin.gif" border="0">

Originally posted by Cliffhanger:
<STRONG>
I'm pretty sure that is with the Torqe converter theory figured in.

let's see..... 2.5(tranny 1st) x 2(torque conv) x 2(X-fer low) x 3.09(rear end) = 30.9

IS that math correct????</STRONG>

Tom and I had a little debate about this. Can't remeber what topic it was under. I figure in the 2x for the Torque Convertor, Tom does not.

Joe <IMG SRC="smilies/smokin.gif" border="0">

Hey, I got a couple of ideas.

First try - how about a 727 auto into a modified (no front half) Dana 20 into a Dana 20 into 3.73 gears with the torque converter it's about 76 to 1 ratio.
Second try - 727 auto into a T18 close ratio, into a Dana 20 into 3.73 gears. with the torque converter it's about 150 to 1 in it's lowest range. Should be about to shift by dropping into neutral.

I know the first one will work, but what about the second? I have the parts to go either way except I need the bull gear. Anyone have an extra laying around?
<IMG SRC="smilies/biggrin.gif" border="0">

Ritch

Originally posted by jdjanda:
<STRONG>Tom and I had a little debate about this. Can't remeber what topic it was under. I figure in the 2x for the Torque Convertor, Tom does not.

Joe <IMG SRC="smilies/smokin.gif" border="0"></STRONG>

I figger with a good stock low-stall converter that I have a hard time holding the rig back at 700rpm.. there isn't a whole lot of extra crawl ratio available from it.

With a worn out converter on it's last leg.. sure. ;-)


Hmmm.. wait a sec.. we talk of *torque multiplication* from a converter. Not "speed reduction" from the converter.

perhaps this "2:1" figure has a place, but not in what wheelers call a CRAWL ratio.

You may have 2x the torque available, but that doesn't directly help you go any slower.

Yes n' no. With a 4cyl, I couldn't crawl with 30:1 at 700rpm. I lacked the torque. I needed more RPM to make the torque I needed.

OTOH, with a V8, it'll lug along at 500rpm with the same crawl ratio.

Crawl ratio stayed the same, but available torque roughly doubled at a given RPM, which allowed me to go a good bit slower - instead of needing 1500rpm, I need 750rpm, which *effectively* halved my crawl *speed*.

Unlike a slushbox, my torque was ALWAYS doubled, not just at/below the stall speed of the converter.

I still hold that the "2x" multiplication of a slushbox has little value in rock-crawling unless you're always stopping/going just a few feet at a time. <IMG SRC="smilies/thefinger.gif" border="0">

Sounds to me like some wide-box envious auto guys got together and tried to come up with a way their transmissions would be "better". <IMG SRC="smilies/biggrin.gif" border="0"> <IMG SRC="smilies/thefinger.gif" border="0"> <IMG SRC="smilies/biggrin.gif" border="0">

I'm rambling, but just a little bit..

How about a crawl-off one of these days.

Say.. a wide-box T19, 3.07 gears, Dana 20, 31s with a stock V8.

Against a slush-box standard geared 727, 4.09 gears, Dana 20, 31s, and a stock V8.

See who can crawl the slowest. First without using the brake, then with using the brake (and measure how much those trans temps go up!)

The wide box at 39:1, or the slush-box at 20:1 (or an effective 40:1)

Then compare the wide-box in 2nd gear.. at 18.5:1 to the auto.

Maybe Pat can come up with two contenders for next year's NWBRU and we'll compare.

Or he could just go through last year's "slow obstacle" figures and see if any 727 rigs were comparable to a wide-box and see how their times came out..

On my last Moab Safari I never used low range! I did'nt even notice I was'nt in low range until I broke both rear axles <IMG SRC="smilies/crybaby2.gif" border="0"> But I am running too much power for the rocks! I'm running an auto with a 2500 stall converter that does great by the way. 5:13s with 39.5s <IMG SRC="smilies/usa.gif" border="0">

Originally posted by tsm1mt:
<STRONG>I figger with a good stock low-stall converter that I have a hard time holding the rig back at 700rpm.. there isn't a whole lot of extra crawl ratio available from it.

With a worn out converter on it's last leg.. sure. ;-)


Hmmm.. wait a sec.. we talk of *torque multiplication* from a converter. Not "speed reduction" from the converter.

perhaps this "2:1" figure has a place, but not in what wheelers call a CRAWL ratio.

You may have 2x the torque available, but that doesn't directly help you go any slower.

Yes n' no. With a 4cyl, I couldn't crawl with 30:1 at 700rpm. I lacked the torque. I needed more RPM to make the torque I needed.

OTOH, with a V8, it'll lug along at 500rpm with the same crawl ratio.

Crawl ratio stayed the same, but available torque roughly doubled at a given RPM, which allowed me to go a good bit slower - instead of needing 1500rpm, I need 750rpm, which *effectively* halved my crawl *speed*.

Unlike a slushbox, my torque was ALWAYS doubled, not just at/below the stall speed of the converter.

I still hold that the "2x" multiplication of a slushbox has little value in rock-crawling unless you're always stopping/going just a few feet at a time. <IMG SRC="smilies/thefinger.gif" border="0">

Sounds to me like some wide-box envious auto guys got together and tried to come up with a way their transmissions would be "better". <IMG SRC="smilies/biggrin.gif" border="0"> <IMG SRC="smilies/thefinger.gif" border="0"> <IMG SRC="smilies/biggrin.gif" border="0">

I'm rambling, but just a little bit..

How about a crawl-off one of these days.

Say.. a wide-box T19, 3.07 gears, Dana 20, 31s with a stock V8.

Against a slush-box standard geared 727, 4.09 gears, Dana 20, 31s, and a stock V8.

See who can crawl the slowest. First without using the brake, then with using the brake (and measure how much those trans temps go up!)

The wide box at 39:1, or the slush-box at 20:1 (or an effective 40:1)

Then compare the wide-box in 2nd gear.. at 18.5:1 to the auto.

Maybe Pat can come up with two contenders for next year's NWBRU and we'll compare.

Or he could just go through last year's "slow obstacle" figures and see if any 727 rigs were comparable to a wide-box and see how their times came out..</STRONG>


Not even close. The auto's will not crawl as slow as the wide ratio sticks, unless you are on the brake.

However, I think you exxagerate the heat problem. I can crawl up steep hills, etc, for long periods of time without heating my tranny up significantly. Only real heating occurs when climbing really tall difficult obstacles, where I am running my RPM's up, and spinning tires on rock. Then, I start heating up.

All that being said, all things being equal, I think a manual wide ratio is better in the rocks than an auto. The auto will do better, but it will overheat.

OTOH, I think an auto with a doubler, is going to outperform a wide ratio. The torque converter is not going to be slipping as much, the tranny is not going to be working as hard. So, you get the convenience of the auto tranny, and the torque doubling of the torque converter when coming off a stop onto a really tall obstacle. Anyone driving a wide ratio smoked or overheated their clutch while running in the rocks? Same difference. And, seriously overheating a clutch can be almost as expensive as seriously overheating an auto tranny. Difference is, with an auto tranny, you can put a bigger tranny cooler on to control heat. Not much you can do to keep your clutch cool.

So, head to head, I would say wide ratio is better in the rocks (doesn't necessarily perform better, but properly used it is more durable). But, put a Klune V or Crawler box in there, and the auto wins, hands down.

Just my opinion.

Now, onto the torque doubling aspect of the torque converter.

The torque converter is nothing more than a variable liquid gear.

Take a rig, put 1 engine revolution in, with wide ratio 6.0 (?) gear, d20 2.0 gear, and d44 3.54 gear and you get 1/42.5 revolutions of the axle, or a 42:1 ratio.

Put a doubler in there. It now takes 2 engine revolutions to get the same. Or, for the same engine revolution, you get half as many turns out of the axle. 84:1 ratio. Twice the torque.

So, if your engine rpm's double for the same rotation of the wheel, you have doubled your torque.

So, a torque converter when fully engaged gives a 17.1:1 ratio. (727 2.5 x 2 x 3.54)However, if the torque converter is slipping, and the engine is spinning twice as fast as the tranny input shaft, you have doubled the engine rpm, while maintaining axle speed, effectively doubling your torque. As the tranny catches up to the torque converter, the engine rpm to tranny speed ratio decreases, and torque is reduced, until the torque converter reaches its equilibrium.

So, off the start, up until the tranny input shaft is turning at the same speed as the engine crank, you have increased torque.

Makes sense to me, but might still have some errors in the logic.

All this talk about crawl boxes and dual t-cases has got me thinkin' <IMG SRC="smilies/eek.gif" border="0"> My SII already has a D300 in it and I've got a Jeep D300 sitting on the garage floor. Anybody got any info on putting these two cases together for a dual-case setup <IMG SRC="smilies/question.gif" border="0"> <IMG SRC="smilies/question.gif" border="0">

Originally posted by Hooper:
<STRONG>
I think a manual wide ratio is better in the rocks than an auto. The auto will do better, but it will overheat.
</STRONG>

I think an auto has many admirable qualities that may make it an *overall* better CHOICE, but I think we agree that a stick, for strictly crawling, is a better, more economical choice. Even a close ratio T19 would be better than a 727 for true crawl.

<STRONG>
OTOH, I think an auto with a doubler, is going to outperform a wide ratio. The torque converter is not going to be slipping as much, the tranny is not going to be working as hard. So, you get the convenience of the auto tranny, and the torque doubling of the torque converter when coming off a stop onto a really tall obstacle.
</STRONG>

I'll give you that. A stick and an auto with the *same* final drive ratio, I'd give the edge to the auto in most situations because of the converter.

Say, 50:1 with a stick, and 50:1 with an auto and crawler box.

The auto will launch smoother, you can upshift going uphill, etc. It won't crawl *downhill* *QUITE* as well, but pretty darn close (assuming a stock low-stall converter in good condition)

b/c you won't be slipping the converter, the heat won't be as much of a problem either.

I agree - ratio to ratio, the auto, IMHO, would be a better overall choice.

But if you have to account for the "2:1" converter "advantage" to get the ratios the same.. no way, stick please.

<STRONG>
Anyone driving a wide ratio smoked or overheated their clutch while running in the rocks?
</STRONG>

Only did it with my close ratio 4spd.. and the 196. I had to rev it up and drop the clutch to get anywhere with the 4.09/33s..

<STRONG>Difference is, with an auto tranny, you can put a bigger tranny cooler on to control heat. Not much you can do to keep your clutch cool.
</STRONG>

Sure there is. 1) don't slip it - let it engage. 2) If you're overpowering the clutch (yeah, baby! That's TORQUE) then you just step up to a bigger clutch.

I don't know of any Scouter running a 12" clutch and having problems with it.. but if they do, there's a 13" out there..

I've actually watched a buddy smoke the clutch in his EB. One fast little Bronco with a GT40 headed 302, toploader 4spd, Dana 20 and ~31" Terra tires. FAST.

'cept a year ago he bolted on some paddles for the mud-bog.. paddles had too much traction. Instead of his usual smokin' tire launch the Bronco lurched forward and the 302 sang, but no-go. The clutch couldn't handle the power, and the tires had too much traction.

<STRONG>
So, head to head, I would say wide ratio is better in the rocks (doesn't necessarily perform better, but properly used it is more durable). But, put a Klune V or Crawler box in there, and the auto wins, hands down.
</STRONG>

Of course, to be fair, lets put a Crawler onto wide T19 and talk some more. <IMG SRC="smilies/biggrin.gif" border="0">

I guess that's part of the point. The 727 needs the crawler box just to more-or-less catch up with the wide box.

<STRONG>
Take a rig, put 1 engine revolution in, with wide ratio 6.0 (?) gear, d20 2.0 gear, and d44 3.54 gear and you get 1/42.5 revolutions of the axle, or a 42:1 ratio.

So, if your engine rpm's double for the same rotation of the wheel, you have doubled your torque.
</STRONG>

Agreed.

<STRONG>

So, a torque converter when fully engaged gives a 17.1:1 ratio. (727 2.5 x 2 x 3.54)However, if the torque converter is slipping, and the engine is spinning twice as fast as the tranny input shaft, you have doubled the engine rpm, while maintaining axle speed, effectively doubling your torque. As the tranny catches up to the torque converter, the engine rpm to tranny speed ratio decreases, and torque is reduced, until the torque converter reaches its equilibrium.

So, off the start, up until the tranny input shaft is turning at the same speed as the engine crank, you have increased torque.
</STRONG>

Roughly. Technically if your RPM doubles, your torque *doesn't*.. your torque goes up by the amount the engine produces at the NEW RPM vs. the original RPM.

Thus, if the converter is "locked" (no, not physically locked, and I know it's never a true 1:1 ratio, but for discussion, let's call it "locked" when the input and output RPMs roughly match - no slip from the converter) and you're actuall road speed is, say, 1mph.. but when you apply more throttle, the converter slips, and the RPM doubles, but your road speed is still 1mph, you have NOT doubled the torque. You've changed from, say, 100lbs-ft at 700rpm to, perhaps, 200lbs-ft at 1400rpm - but that could also be 300lbs-ft at 1400rpm. Depends on the cam, compression, bore/stroke/blah blah.

Generally the engine works better at a higher RPM, makin' more power which is more useful.

<STRONG>
if the torque converter is slipping, and the engine is spinning twice as fast as the tranny input shaft, you have doubled the engine rpm, while maintaining axle speed, effectively doubling your torque.</STRONG>

Lessee.. try my rig here.

Old stock converter (last year). 304 that should make 390+lbs-ft from 2000rpm to 4500rpm. (peak of 405-ish)


At 700rpm, it was pulling. At 1200rpm, the brakes wouldn't hold the engine back. I couldn't "stall" it past 1200rpm.

If I let off the brake at 700rpm, it would quickly get to speed and stay there.

Since the trans shaft isn't turning at all at a dead stop, and engine RPM was from 700rpm to 1200rpm, do I have 700x or 1200x the torque available? Or is it just 200lbs-ft going to the input shaft? (or whatever it is at 1000rpm)

My motor doesn't make any power at 1000rpm. It starts at 1500, but really likes 2000-5500rpm. Using a higher stall converter (a bit over 2000rpm now) just lets me avoid the low-torque bottom end and launch with 400lbs-ft at my disposal (BTW, this is death to soft flexy leaf springs). It was a dog coming out of the hole with the stock converter (compartively, anyhow).

I seem to be having a hard time making sure my arguments are clear today.. too much multitasking. <IMG SRC="smilies/biggrin.gif" border="0">

Originally posted by jdjanda:
<STRONG>Just looked over your website. Too Bad you're in Nebraska, I could solve you tub dilema also.

Joe <IMG SRC="smilies/smokin.gif" border="0"></STRONG>


What TUB problem????

Originally posted by tsm1mt:
<STRONG>of course, the Atlas will only work if you convert your 727 over to the round SAE/Jeep-300 bolt pattern with Dodge parts..

At which point you can run the Tera 4-1 for a 300, a Jeep 300, an Atlas, a Klune-V, or...

Could also go with the Dodge NP203 adapter, an NP203 reduction box, and an NP205 if you wanted BEEF..

Then again, *I* think that just makes the weak link the adapter or the aluminum transmission case.. and it sucks to break the trans case. <IMG SRC="smilies/biggrin.gif" border="0"></STRONG>


That was a lot to take in.

I guess I could do any of the above but since I already have the TH350&NP205 that goes along with it, guess which I'd probably do. That way I'd only have to find a TH350-NP203. and buy the kit.

In which case I'd probably ditch the 727/D20 all together.

BACK TO THE DRAWIG BOARD <IMG SRC="smilies/nuke.gif" border="0">

Originally posted by Cliffhanger:
<STRONG>
That was a lot to take in.

I guess I could do any of the above but since I already have the TH350&NP205 that goes along with it, guess which I'd probably do. That way I'd only have to find a TH350-NP203. and buy the kit.

In which case I'd probably ditch the 727/D20 all together.

BACK TO THE DRAWIG BOARD <IMG SRC="smilies/nuke.gif" border="0"></STRONG>

Well, if you didn't have your heart set on a Chubby 'mill..

There's an adapter to mate an SV-8 up to a TH700-R4 (and I imagine a TH350)

now wouldn't *that* be a fun combo? Built 392/TH700R4 (low 1st plus OD), NP203, NP205.. and take your pic on rear gear..

Originally posted by tsm1mt:
<STRONG>
Then again, *I* think that just makes the weak link the adapter or the aluminum transmission case.. and it sucks to break the trans case. <IMG SRC="smilies/biggrin.gif" border="0"></STRONG>

Where is there alluminum in THAT set-up?? The 203->205 set-up eliminates the aluminum section of the 203, and the 205 of course is bullet-proof and the kit uses a steel adapter *I believe* and even if that little adapter is aluminum I think it's small enough to be stout.

Originally posted by Cliffhanger:
<STRONG>Where is there alluminum in THAT set-up?? The 203->205 set-up eliminates the aluminum section of the 203, and the 205 of course is bullet-proof and the kit uses a steel adapter *I believe* and even if that little adapter is aluminum I think it's small enough to be stout.</STRONG>

With the 300, I think the tailhousing is still aluminum - haven't looked at the 727-203 setup.

And the 727 case is still aluminum.

http://tigger.tmcom.com/~tsm1/scout/jpg/racer/6_10_2001/29.jpg

Then again, I don't know of anyone else off the top of my head that's broken a 727 case.. <IMG SRC="smilies/biggrin.gif" border="0">

I know of a few folks that have blown up the tailhousing adapters for the Dana 20.

As long as your front driveshaft isn't too long, and you aren't participating in activities that tend to destroy your front suspension and smash the front driveshaft into the t-case, I wouldn't worry about breaking that part...

I perfere a standard over a auto any day, the first thing i did to my terra is get rid of the 727 and install a t-19 close, with 4.56's and a dana 20 i have a 37:1 crawl ratio, it works but could be better, i have a wide t-19 and a Dana 300 sitting in the shed so that will get me to 71:1 and i can't wait. So SM465 to NP203's are hard to find i have one sitting in the back yard, i was thinking of using the NP203 gear reduction box behind my t-19 with either a dana 20 or NP 205 behind it. I could see in some places where a auto would be nicer than a standard, in traffic thats for sure, but off road i have never had to slip my clutch, and when i have the auto i had some major heating problems.

Originally posted by BenW:
<STRONG>As long as your front driveshaft isn't too long, and you aren't participating in activities that tend to destroy your front suspension and smash the front driveshaft into the t-case, I wouldn't worry about breaking that part...</STRONG>

<IMG SRC="smilies/biggrin.gif" border="0"> I doubt any sane person would waste a 727 'case.. but I have heard reports of broken tailhousings - not from bottoming the driveshaft or thrashing the suspension, but from too much right-foot.

Built392/BigBlock, high traction tires & surface..

I think it's generally a toss-up whether the Dana 20 'case goes or the tailhousing goes.

I also broke one adapter because I'd wasted the transmission mount which let the tranny flop a bit too much and the adapter couldn't handle the stress of the Dana 20 coming down and the trans hittin' the x-member solidly.

Wasted trans mount bushings are not just a racer thing - I seem to go through one poly T19 mount in my trail rig a year.

I know the 4spd adapter is stronger than the Dana 20 - I ripped the mounting ears off a '20 behind my 4spd but the T19->D20 adapter held together just fine.

I was in 2wd at the time, and I wasn't racing my trail rig - but I did have too much skinny pedal.

Originally posted by tsm1mt:
<STRONG>Well, if you didn't have your heart set on a Chubby 'mill..

There's an adapter to mate an SV-8 up to a TH700-R4 (and I imagine a TH350)

now wouldn't *that* be a fun combo? Built 392/TH700R4 (low 1st plus OD), NP203, NP205.. and take your pic on rear gear..</STRONG>

The TH700R4/203 combo wouldn't work. For that doubler set-up you have to have a 203 from a TH350 and a 205 from a TH350

You'd have to have a 700R4/NP205 combo. DID THEY EVEN MAKE THOSE????

I have a Caddy 500 sitting in the back of my blazer that will land in the front of my ScoutII. Then I will either get an adapter to mate it to the TH350 or I will get a BOP TH400 (we've had that Jeep conversation before) and go from there with a D20 etc etc..

I like Chevy motors (I have one for sale) but I LOVE Cadillac motors

[ 10-09-2001: Message edited by: Cliffhanger ]

Originally posted by TORC:
<STRONG>All this talk about crawl boxes and dual t-cases has got me thinkin' <IMG SRC="smilies/eek.gif" border="0"> My SII already has a D300 in it and I've got a Jeep D300 sitting on the garage floor. Anybody got any info on putting these two cases together for a dual-case setup <IMG SRC="smilies/question.gif" border="0"> <IMG SRC="smilies/question.gif" border="0"></STRONG>

You might be able to get a d300 flip kit (c/o yj's and tj's) and have the front 300 upside down (probably the jeep case) and put the back case on like a d300/d20 doubler??? Not sure how easy this would be or if there are adapters available. <IMG SRC="smilies/confused.gif" border="0"> I am sure its possible... A d300/D300 doubler would be nice w/ 4:1 in both <IMG SRC="smilies/biggrin.gif" border="0">