tf727 question

[CJ5-Man]

I'm looking at putting a tf727 in my CJ w/ a 360, but want to keep the dana20.

Is the transfer case adapter off a IH tf727 removable? is there a way to kluge it onto a non IH 727? Did any of the scouts that came w/ an AMC I6 use the 727 and d20?

[ 09-22-2001: Message edited by: The Flem ]

[jdjanda]

OK, here is the deal. Yes you can use the tail housing off an IH 727 to bolt up a Dana 20 to your AMC 727. Couple of things, the IH D20 adapters use a 27 spline shaft to carry the bull gear, and a 27 spline D20 bull gear. This means you cannot use the Tera Low kit for D20's as Tera does not make a 27 spline kit, you cannot also do the D18/Bronco gear swap. Jack O'brien makes a 3.7 kit for D20's with 27 spline bull gears, but it is big dollars.

The D20 tail housing uses a special bearing that is currently no longer in production, so hope the unit you have is in good condition, you can also have the bearing reatiner opened up a tad to accept a more commonly available Timken bearing.

Now for some good news, I happen to have an extra D20 tail housing for an IH 727, but the bull gear is loaded with surface rust, you interested in a trade for the D300 tail housing, or I might buy it if want to sell it.

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

[ 09-23-2001: Message edited by: jdjanda ]

[CJ5-Man]

Originally posted by jdjanda:
<STRONG>you interested in a trade for the D300 tail housing, or I might buy it if want to sell it.

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

[ 09-23-2001: Message edited by: jdjanda ]</STRONG>

I don't have a d300, i have a d20. I'm trying to get a lower crawl ratio in my cj5 and from the looks of it, an auto tranny is the cheapest way to do it

[tsm1mt]

Originally posted by The Flem:
<STRONG>I'm looking at putting a tf727 in my CJ w/ a 360, but want to keep the dana20.

</STRONG>

In '72-74 you could get a 258/727/D20 in a Scout II.

The Dana 20 tailhousing adapter will swap onto a non-IH 727, but you'll need to tear down the 727 to get the Scout tail-shaft in it.

What did your 727 come from? You can swap a Jeep '300 in place of an NP231 to get a right-drop and 2.62:1 gear-drive.. that's what jdjanda was wanting. <IMG SRC="smilies/biggrin.gif" border="0">

[jdjanda]

Actually I want the tail housing, I can find a Heep Dana 300 fairly cheep. I was under the impression that the tail housing should just unbolt from the ass-end of the tranny. I do have an extra IH727/D20 adapter that I would be willing to trade for the AMC727/D300 adapter.

Maybe I'll save it until Tom has used up all the IH727/D20 adapters and sell it to him for big bucks.

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

[tsm1mt]

Originally posted by jdjanda:
<STRONG>Actually I want the tail housing, I can find a Heep Dana 300 fairly cheep. I was under the impression that the tail housing should just unbolt from the ass-end of the tranny. I do have an extra IH727/D20 adapter that I would be willing to trade for the AMC727/D300 adapter.

Maybe I'll save it until Tom has used up all the IH727/D20 adapters and sell it to him for big bucks.

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

You have to replace the tailshaft, too. Not just the adapter. Remember that 27-spline bit? ;-)

If I run out of Dana 20 adapters I know you can buy the Dana 300 adapters and tailshaft new.. I'll just have to go up in tire size to keep my effective gearing where it is (2:1 Dana 20 * 4.88s and 31s.. vs 2.62*4.88 and.. 35s?)

Either that, or I've had someone express an interest in seeing a 700R4 to SV-8 adapter being used in competition. <IMG SRC="smilies/biggrin.gif" border="0">

[Scout Dude]

Originally posted by jdjanda:
<STRONG>OK, here is the deal. Yes you can use the tail housing off an IH 727 to bolt up a Dana 20 to your AMC 727. Couple of things, the IH D20 adapters use a 27 spline shaft to carry the bull gear, and a 27 spline D20 bull gear. This means you cannot use the Tera Low kit for D20's as Tera does not make a 27 spline kit, you cannot also do the D18/Bronco gear swap. Jack O'brien makes a 3.7 kit for D20's with 27 spline bull gears, but it is big dollars.

The D20 tail housing uses a special bearing that is currently no longer in production, so hope the unit you have is in good condition, you can also have the bearing reatiner opened up a tad to accept a more commonly available Timken bearing.

Now for some good news, I happen to have an extra D20 tail housing for an IH 727, but the bull gear is loaded with surface rust, you interested in a trade for the D300 tail housing, or I might buy it if want to sell it.

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

[ 09-23-2001: Message edited by: jdjanda ]</STRONG>

this is directly from Tera's website:
"Available April ‘99. New five-gear kit for Dana #20s [...] ‘72-79 Scouts. [...]" So some Scout t-cases will work

[Old Scout]

Originally posted by Scout Dude:
<STRONG>this is directly from Tera's website:
"Available April ‘99. New five-gear kit for Dana #20s [...] ‘72-79 Scouts. [...]" So some Scout t-cases will work</STRONG>

It's all spelled out above,no Terra low for a 727 scout.

[tsm1mt]

Originally posted by Scout Dude:
<STRONG>this is directly from Tera's website:
"Available April ?99. New five-gear kit for Dana #20s [...] ?72-79 Scouts. [...]" So some Scout t-cases will work</STRONG>

Yep.. ALL Scout t'cases will work.

Too bad they won't work with all Scout *transmissions*. <IMG SRC="smilies/biggrin.gif" border="0">

Only a few very limited production runs of the 727->Tera20 and 727->Tera300 bullgears have been made, and those were early on.

The Tera kits will work behind a T90/T15/T18/T19 Scout II transmission just fine. So will Bronco 2.46:1 gears.

OTOH, with the 727 you can run the '300 tail-housing and use a Klune and a Dana 300 if you wanted. <IMG SRC="smilies/biggrin.gif" border="0">

[jdjanda]

The only option I know for low gears using the IH 727 27 spline, and Dana 20 is the Jack O'brien Rock Eater kit. If I remember correctly the kit gives a 3.7:1, but the cost is over $1,500.00, more then the cost of a used Dana 300, AMC 727 housing and 4:1 Tera kit. The O'brien kit is suppose to be the shit, I spent over an hour on phone with Jack discussing his kit, according to him the kit uses top notch material, improved teeth cut to provide less stress on the case, etc. I can track his number down if someone is interested.

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

[tsm1mt]

Originally posted by jdjanda:
<STRONG>The only option I know for low gears using the IH 727 27 spline, and Dana 20 is the Jack O'brien Rock Eater kit. If I remember correctly the kit gives a 3.7:1, but the cost is over $1,500.00, more then the cost of a used Dana 300, AMC 727 housing and 4:1 Tera kit. The O'brien kit is suppose to be the shit, I spent over an hour on phone with Jack discussing his kit, according to him the kit uses top notch material, improved teeth cut to provide less stress on the case, etc. I can track his number down if someone is interested.

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

No, there's another.

Mr.Scout sells their own "Doubler" that is a custom 'cased Dana 20 that mates where any Dana 20 used to live. It just uses standard '20 bull-gears on the transmission, so you can bolt it behind a T19 or 727.

It then provides 2:1 low-range and the output end of the doubler looks like a manual transmission Dana 20 adapter.

Thus you can run a 2:1 Doubler behind the 727, and then a 2:1 Dana 20, 2.46:1 EB geared Dana 20, 3.15:1 Tera 20, or a 4:1 Tera SII Dana 300 behind it.

If you're running a 4spd, the Doubler itself can have the 2, 2.46, or 3.15 gears installed (I think there's a 2.26-ish Bronco gearset, too, that'd work)

I think it's $1800 though - OTOH, you get 2x the gear selections, and even if you go the cheapest route, for $1800 you get 4:1 vs. $1500 and 3.7:1 with O'Brien's kit - and you have the option of shelling out more coin later for more crawl.

Some day when I'm done buying $$$ shop equipment and building motors, I think I'd try the Doubler behind my wide T19, and in front of the 2.46:1 Bronco geared 'case I've been waiting to reassemble. ~5:1 compound low and still a 2 or 2.46 low-range for the times the throttle is necessary.

[tsm1mt]

Originally posted by The Flem:
<STRONG>
I don't have a d300, i have a d20. I'm trying to get a lower crawl ratio in my cj5 and from the looks of it, an auto tranny is the cheapest way to do it</STRONG>

How can a 2.45:1 auto get you a lower crawl? Or even 2.77:1? Even a T90 3spd is around 3:1 in 1st gear.

In a SII, the 727 is an inch longer than the stick shift combination - but the T90/T15 3spds have longer transfer case adapters so the 3spd and 4spd sticks are the same OAL.

How much rear driveshaft will you have left in a '5?

[Scout Dude]

Originally posted by Old Scout:
<STRONG>It's all spelled out above,no Terra low for a 727 scout.</STRONG>

What did you expect me to read all of that? <IMG SRC="smilies/biggrin.gif" border="0"> I don't even have an auto. As it is now, I'm ditching my D20 for a 300. Too many options available for a 300 adaptor that the 20 doesn't have.

[jdjanda]

Originally posted by tsm1mt:
<STRONG>No, there's another.

Mr.Scout sells their own "Doubler" that is a custom 'cased Dana 20 that mates where any Dana 20 used to live. It just uses standard '20 bull-gears on the transmission, so you can bolt it behind a T19 or 727.
</STRONG>

Don't go there, we were not talking about 'doubler' options <IMG SRC="smilies/biggrin.gif" border="0">, purly gears for the 727 Dana 20. But yes the Mr Scout box is an option I have considered as well. I'd go with a Klune 4:1 if I was going to setup a doubler, but even the Heep guys can use the Mr Scout box if they have the D20.

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

[jdjanda]

Originally posted by tsm1mt:
<STRONG>How can a 2.45:1 auto get you a lower crawl? Or even 2.77:1? Even a T90 3spd is around 3:1 in 1st gear.
</STRONG>

'Torque converter multiplication'

An automatic at low RPM's acts a 3:1 multiplier to the gear, I.E. first in the 727 is 2.45 * 3 = 7.35. I able to wheel my 3.54 geared Scout fairly well, just need to keep an eye on the temp gauge. Still want to go to 4.10's and 4:1 in the T-case, should put me around a 120:1 with torque multi, 40;1 without. Of course it's all theory, and I still plan to use a manual in my other rig.

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

[tsm1mt]

Originally posted by jdjanda:
<STRONG>'Torque converter multiplication'
</STRONG>

Hogwash! <IMG SRC="smilies/thefinger.gif" border="0"> (not a flame, but maybe we can get a lively discussion going today.. <IMG SRC="smilies/biggrin.gif" border="0"> )

<STRONG>
An automatic at low RPM's acts a 3:1 multiplier to the gear,
</STRONG>

This "torque multiplier" has gone up in the last couple of years I guess. It used to be I saw 2:1 being used. <IMG SRC="smilies/biggrin.gif" border="0">

<STRONG>
just need to keep an eye on the temp gauge. Of course it's all theory, and I still plan to use a manual in my other rig.
Joe <IMG SRC="smilies/smokin.gif" border="0"></STRONG>

The only time you get any torque multiplication is *right* off the line when the converter is slipping (good idea to watch the temp! <g>) - but as soon as it "hooks up" you're stuck with whatever your TRUE numerical crawl ratio is.

Unless you can keep your transmission cool enough that you can slip the converter all day long (hmm.. maybe I see a market for some worn-out converters..) I don't really see where it matters.

Going down a hill, does the 2:1 or 3:1 help your creep ratio at all? <IMG SRC="smilies/biggrin.gif" border="0">

Even if you want to stick with the 2:1 reduction.. all it's really doing is effectively the same as starting off in granny-low on a wide T19 and then *immediately* shifting to 2nd gear. From 6:1 to 3:1 as soon as the Scout starts to roll.

Right? From 5:1 to 2.5:1 as soon as the converter "hooks up".

I've watched automatic rigs take "advantage" of this phenomenon on our snow runs.

They apply a little throttle, but can't get the tires turning.. a little more.. a little more go pedal.. then as soon as the tires turn, they're spinning. Meanwhile the stick guys just put it into granny and ease off the clutch and putter along.

BTDT myself when I wheeled my auto T'all. It's effective crawl is about the same as my Scout II if you take the torque multiplication into effect.

345 - 6.32 * 2 * 4.09 for the Scout.
392 - 2.45 * 2 * 3.73 for the T'all.

Two entirely different driving techniques are required.
I admit the converter makes it easier to take off on a hill, but I still think it shouldn't be included in any true crawl-ratio debate.

Or maybe I should start taking "clutch-slip" into account when I factor my T19's crawl ratio? I could go with an 8" clutch and let it slip and I, too, could get a torque multiplication.

In my other Scout I haven't noticed any "torque multiplication" from the converter - just the fact that it won't hook up until 2500rpm and the engine's making a lot MORE torque at that point than at 700rpm (it'll hardly idle at 700.. heh).

[jdjanda]

I'm up for a good one <IMG SRC="smilies/thefinger.gif" border="0"> I'm not a Binder newbie <IMG SRC="smilies/biggrin.gif" border="0"> (unlike ol Chewie, have not heard from him today) I can take it. Do you want to talk about blinker fluid properties.

It's not like the TC lock's up, there is always some slip, and we're not talking a lockup converter. I'd say with my worn out 727 I'm getting 5:1 multiplication. <IMG SRC="smilies/biggrin.gif" border="0"> So it's as if your ratio moves from 7:1 to about 2.7:1 before shifting. You might see 2.5:1 if held in first, but never 2.45:1. Agreed that slipping the clutch is the same concept, only harder to control as you only have two feet. We are comparing Apples and Oranges. The two are different styles, sorta like Unix and NT, Manuals are like Unix, hard to learn, but powerful once you have them down. Auto's are NT, appearing to be easy to first learn, but very difficult to master unless you are willing to work out of the box. I've driven both, I'm in the middle as to what I like. With a manual I know I'll always be able to get home even though I'm more likely to break drive train components. The auto I always have a little fear in the back of my mind that something will give out. I don't believe in trailering my rigs so it's got to get me there and back.

The auto requires two feet to drive in the rocks, I use the brake to control the speed when I start to move and the tire speed wants to come up. Not always perfect, but you can feel when you are starting to move, you've got to bring the RPM's down, but not too far that you lose momentum. Manuals are the opposite, start with the clutch out, if you move you're fine, if your not going anywhere then slip the clutch till you go. It's almost as if the autos are slow in fast out on an obstacle, and manuals are fast in, slow out. Meaning with autos you have complete control of the speed you enter with, but not always out with, manuals need speed to get started, but then can slip the clutch to slow on the way out. Both have there ups and downs.

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

[tsm1mt]

Originally posted by jdjanda:
<STRONG>
It's not like the TC lock's up, there is always some slip, and we're not talking a lockup converter.
</STRONG>

Right, "lock up" isn't the correct term, but there is a point where slip is minimal - where you're pretty much just losing some "efficiency" and not an appreciable amount of RPM to the slip.

<STRONG>
Agreed that slipping the clutch is the same concept, only harder to control as you only have two feet.
</STRONG>

One of the many reasons I have a hand-throttle. <IMG SRC="smilies/biggrin.gif" border="0">

One of these days I'll add my second hand throttle - a thumb-switch on the gearshift to go along with the dash mounted T-locking cable I already installed.

<STRONG>
I've driven both, I'm in the middle as to what I like.
</STRONG>

I used to despise autos. After building my race Scout and driving my Travelall daily, I have a better respect for 'em.. but my stick equipped Scout II is still the most street-legal fun rig to drive.

I am, however, re-evaluating whether to use one of my close T19 4spds or a built 727 for the "street" Scout I hope to get back to working on "some day"..

<STRONG>
I don't believe in trailering my rigs so it's got to get me there and back.
</STRONG>

I USED to not believe in trailering my rigs.

Then I snapped a main-leaf while in Moab with a 700+ mile drive just to get home, while towing with my Scout.

Not exactly something I carry in my "trail spares" pack..

FYI, I took the last SII main-leaf in town. <IMG SRC="smilies/biggrin.gif" border="0">


On my auto SII, I've also had problems with the shifter cable melting from one reason or the other. The last B&M cable I put in we wrapped with aluminized duct-tape before installing - so far so good. I now have an $80 super-duty B&M cable that I need to install - but I think I'll wrap it before it goes in, too.

I've ruined 3 of the $40 cables.. <IMG SRC="smilies/frown.gif" border="0">

Each time I made sure it was routed as far from the headers as I could get it.. but I guess wired against the block isn't enough?..

[ 09-25-2001: Message edited by: tsm1mt ]