Thoughts on automatic trannies....

[NECKSTER]

I'm thinking of going with a 727 in my rig. I've had an NP 435 for about 9 years, and I'm thinking it may be time for a change. Any of you guys use one for rock crawling? I have never owned any sort of wheeling rig with an automatic, so this is all new to me. I am running a 318/435/300 combo right now and would like to try 318/727/300.

BTW- if I do this, I will have an NP 435 for sale with the adapter for a dana 300 (just the tranny and adapter, no t-case)

[oiler]

I think that you would be happy with the change. I had a t-18 and switched for a 727/20 combo in a jeep and really liked it. In fact, my new project jeep will use a 727. Go for it, I think you'll like it.

[Lloyd]

I just went from a CJ-5 with a T-18 / D20 / 4.27's to an M880 with a 727 / NP203 / 4.10's. While I don't claim to have done any "rockcrawling" with the new one, it has seen a little abusive trail time (despite the lack of progress on the buildup, house construction, etc). Neither have deep enough gears to suit me (T-18 was 4.02:1 1st), but the torque converter really makes up for a lot. To me the major difference is seen in compression braking - or lack thereof. In practice this just translates into more use of the brakes, but I hate to ride'em and will change gearing to fix that. I've got a 205 that'll go on as the back end of a doubler someday (soon I hope). Depending on how that feels I may or may not have Wagoner put their 3.6 gears in the 203. With the auto, it's very nice to be able to approach an obstacle, feel the tire come up against it and the vehicle stop, then slowly throttle up until it walks over. It makes a lot of maneuvers much easier; and overall the transition from a manual to auto tranny on the trail feels about the same magnitude improvement as going from manual to power steering. It's really so nice to not need three feet, there's no way you'll regret the change - provided that you do keep a low enough crawl.

To this end, two things that you might want to consider are O'Brien's tcase gears for your 300, and if you're going to build the 727 for this purpose perhaps the 2.77 1st-gear for it. Old Scout posted this link a while back: http://shop.store.yahoo.com/chucker54/lowgearsets.html Having said that, the torque converter really does seem to give you at least a 2:1 advantage in most situations except compression braking (where it's more like 1:2) and climbing in very slow stuff where you're right at stall it feels probably closer to 3:1 extra advantage. But, when you get some engine speed up, ie. clear an obstacle or break over the top of something, the "real" crawl ratio shows up and the converter has the tendancy to shoot the rig ahead somewhat faster than you might want, especially if you're not expecting that effect. You'll get used to it fast though, and learn to lift just a bit sooner.

A big auxillary cooler will be necessary; autos generate a lot of heat. A while back you said that your rig's cooling was "marginal" so don't add the transmission heat to the radiator (neither with an in-tank cooler nor by mounting the trans. cooler in front of it) just mount a big trans. cooler somewhere else and put an electric fan on it.

It's a much different feeling than wheeling a manual. It does take a little getting used to. I'm beginning to think that the only reasons people still run manuals on the trail are that a) they've never tried them, b) they tried something not set up properly - ie. not low enough crawl, or c) they've got a manual and that's what they're gonna run. Overall I think the auto has the potential to be a much better choice.

[NECKSTER]

LLoyd, thanx for your thoughts. I can see what you're saying. I went to the link, and saw some cool stuff, but they don't go into alot of detail. They want to sell you lower gear sets for $400, but don't tell what they are. Also, the lowest converter I could find was 1900-2100 stall speed. Does anyone know a stock converter is? I would think it would have to be a lot less than that.

Also, I had cooling problems years ago when I had "water wetter" in my system. Last year in the hammers, it was 112* outside and my 318 never got above 180* crawling through the canyons. I'd say I have great cooling now. However, that doesn't change the fact that you are right about needing a completely separate cooler with it's own fan elsewhere.

[NECKSTER]

As I think about this more, I wonder if I'm not crazy to just go and throw what seems like is going to be a couple thousand dollars at an auto tranny. A buddy of mine has an adapter to go from the 727 to a dana 300. I wonder if I shouldn't go buy a junkyard tranny, and throw it in for a weekend of fun. I've got external coolers laying around, I have a shifter I can use, and I can make new drivelines myself (I assume the old ones aren't going to work already LOL). If I do get one, I would just need to get the flex plate, converter, and tranny right? I'm starting to like this idea more and more. So, I guess the next question would be, what to get one out of? Are they all the same in older dodge trucks and ramchargers? Can I just go to pick n pull and grab one out of the dozens of 70's and 80's dodge trucks they have there?

Thanx for your help.

BTW- if this doesn't sound like such a hot idea to you guys, let me know. I'm open to suggestions.

[FULLSIZE]

I LOVE MY 435! i will never go auto as i just think theres too many components that can go wrong. don't get water in it, overfill it a quart so it won't starve climbing, but don't forget to drain it back down a quart for the drive home so it wont foam up and start pukeing. i just dont think its an advantage if your geared low enough. just my .02

[Lloyd]

Sorry about the cooling comment, I'd confused you with Fullsize (http://www.pirate4x4.com/forum/showt...threadid=37449). Mancini's gears give you a 2.77:1 first, as opposed to 2.45:1; 2nd and 3rd remain the same. It's a shitload of money for 0.32 improvement in gear one. My transmission was virtually new when I opened it up a while back for a fluid/filter change and B&M TransPack (auto/man valvebody conversion + shift kit) so I have no intention of getting into it again anytime soon. Especially with the option to get 1.96, 3.6, and 7.2:1 in the doubler.

A junkyard auto should easily last long enough to let you know if you want to keep it or not (provided that it does work). In humid areas, AT's stored in yards tend to rust the internals some, which then comes off when you start using them again and shreds the clutch packs. Fortunately (if you do intend to keep it) a complete B&M TransKit only costs $216.75 from Summit; their part # BMM-10229 - and likely that'd be about all you'd need to do to it, besides a good internal cleaning. Easy, simple auto transmission and very tough. All internals are the same '70-79, except for minor differences in the valve body. Cases differ from LA and B/RB patterns. Torque converters/flexplates are balanced to the engine; post-67 318's, 72-back 340's, and all 273's are internally balanced (no weights on converter). You could use a '73 340 or any 360 torque converter if you're willing to grind off that balance weight.

I can't help much with the t-case end, except to say that my 727-203 has a big tailshaft housing with a seven-bolt flange that looks like \_/ with a round top. Mounting foot is cast into this tailshaft housing, and the 203 range box bolts directly to this. Since I don't know what your 727-300 adapter looks like, can't make any comment.

[Lloyd]

Oh yeah, and stock stall speed for converters is around 2000. Some time ago there was a post (Patman?) about some shop making extra-low ones, 1200 or less. Procedure was the same as for a high-stall converter, just tweak the fins the other way. It was before the BB software change, so it's gone now. I haven't felt the need for a low-stall converter yet.

I'm sure that transmission choice is as much a matter of personal taste as anything else. Perhaps my steering analogy was a bit overstated (since a manual transmission usually won't break your thumbs off while driving through the rough) but it sure does make it nice.

[NECKSTER]

So what did you mean by "Cases differ from LA and B/RB patterns." And since my motor came out of a 76, it is externally balanced then? I am going to be throwing my other motor in shortly. It is a 68 318. If I understand you correctly, you're saying they use a different flex plate?

[Hayraker]

I like the 727, my current rig 76 IH scout traveler, bought the rig for $650, the tranny bleeds like a stabbing victim, but never lets me down. It is a trail only rig that sees moderate rock crawling, all I have done is add an external cooler. Because of the auto I am getting away with running the stock high gears in the diffs until I do my axle swap.

[RufusTheRam]

LA motors are the small blocks, 318,360, etc. B/RB are the big block family, 383, 400, 440, 426, etc. they used different cases as mentioned between the two, and in some instances different internals too i think? the big blocks obviously got some stouter stuff. 727's have proven to be bulletproof in drag racing. i haven't heard of alot of people using them for crawling, dodge drivetrains aren't too popular for some reason. i'd imagine they'd be great, though 4 wheeling is a whole other world of stresses than drag racing. the 727 is what i've seen backing about every mopar mud/sand dragster i've seen.

[Lloyd]

LA engines (273, 318, 340 and 360) have a different pattern where the transmission case or bellhousing bolts to the block than B or RB engines - the Hemi uses the same bellhousing pattern as the B or RB wedge-head blocks.

You have two 318's - '76 and '68. Both are internally balanced, both use the same flexplate and flywheel. From '68 to the advent of the Magnums, all 318's are the same - and best identified by five bolts in each valve cover. In the Magnum 5.2, there are a series of changes in the valvetrain, heads, and intake. These have ten bolts in each valve cover, but retain the same internal balance, same bellhousing pattern, same rods, same crank flange pattern etc.

The only externally-balanced LA engines are the 360 (all) and the '73 340 (last year of production). If you find a 727 from '70-79 for any 318, it'll bolt to and work with either of your engines. This year range is best (IMHO) because all those transmissions are nearly identical, and there are lots of parts, lots of junkyard transmissions, etc.

Where you get into trouble with the 318 is in 67-back: this is a different engine altogether, the original A block (although people often mistakenly call the LA engines A engines, and Mopar does it too). The OLD pre-67 318 "A" block has TWO bolts in each valve cover, polyspherical combustion chambers, completely different valvetrain geometry, and NO parts interchange with the '67-up LA-series 318 (although it does have the same bore and stroke). They had more in common (at least in general design) with the early Hemi than with the LA-series wedge-head engines, and were too expensive to make to stay in production. 8 bolts in the crank like the OLD Hemi (332-392 cid) and the early B engines.

[NECKSTER]

Thanx for the clarification on that. But now you have my curiosity. Why do they call it an "LA" motor? What does that stand for? How bout the B/RB?

[FULLSIZE]

cast crank 318s are external balance. different imbalance than a 360.

[Lloyd]

Long ago (1956) Chrysler created the "A" engine. Next (1958) they made the "B" engine (350, 361, etc) which was Bigger. Then they stroked it and increased the deck height for the 383, making the "Raised B". This 383 had a 4.03 bore and 3.75 stroke; it was only made in 59 and 60. Then the "modern" 383 was made on the B in '61-on, and the RB became the 413, then the 426 Wedge and then the 440. Then the polyspherical heads on the A became too expensive to be competitive, and they made the 273 to replace it in '64. Next they dropped the A series altogether, and put the 318 bore and stroke on the 273's basic configuration in '67. Beats me what the L is for, but it differentiates this series from the original A engines. I think it's "Little A" because these are relatively small and light; while the original A was an enormous casting. '68 was the first year for hydraulic lifters on the LA engines.

My book says "All 273 and 318 engines are internally balanced, regardless of whether they have forged-steel or cast crankshafts." Now there was a difference in the 340; they went from internal balance with forged cranks ('72 and back) to external balance with cast cranks ('73 only).
Perhaps this book is wrong (I know it happens ) but that is what it says

[FULLSIZE]

on a 318 with cast crank, the balancer has the carved out counter balance, its not much but it has it. i used a zero balance converter with a cast crank 318 once and it only shook very little. if it were for a weekend to decide if you want an auto, any converter would probably work(note: never tried the durability test with this set-up)

[mtndewmaniac]

Some really great info here. I have been doing some research into dropping in a 318 into my cherokee XJ and for some unknown reasons, there isn't alot of available info concerning Dodge related stuff. Since chrysler owns jeep, I feel my decision using Dodge related component is justified.
I had a '63 D100 that ran like theres no tomorrow, was very pleased with it's performance. Also owned a 72 B100, it too ran great. Since upon finding your info, I have learned that they were entirely different engines.
I agree on why some people are skeptical about using auto VS. manual. I use to be that manual guy. Once I wheeled in my Auto XJ, I have been VERY pleased with its performance. Sure Auto trannys do have more parts, but if maintained properly, they can last.
Once again, THANX for all your input.

[Lloyd]

I'm going to need to do some more research on this 318 balance issue. Now I don't trust that book, and I'll need to bug some other people to sort this out. Fullsize, what years for these different cranks? Hmmm....

[Lloyd]

Mopar Performance claims that all 318's are internally balanced.

[hy_desert_4wheeler]

Every 318 I have run across has been internally balanced.. and they have run the range from 68 all the way to 86..And me and my buddies go through several of them every year along with 360's 383's 400's 440's in our demolitian derby cars..

[FULLSIZE]

news to me..........

[troutbum]

seems to me that if you have a SB 727 just steal a waggy rear output swap it for the dodge rear output and the d300 bolts on.... Am I missing something? s/b really cheap.

Autos are the only way to go... the only thing I miss is the compression braking, I have had a 727 behind a IHC 345 and a BB440 and they have performed beautifully... I am running a full reverse manual valve body and love it. It makes me look like a better driver than I actually am

[FULLSIZE]

i could be wrong, but i could have sworn that if a balancer has part of it carved out(half moon shape), that was the counter balance? auto's aren't the "only way to go". try it neckster, i'd like to know what you think.

[NECKSTER]

So troutbum, are you saying they put 727's in waggoneers?? If so, how common are they? That would be a lot simpler to do.

[Ben W]

Originally posted by NECKSTER
So troutbum, are you saying they put 727's in waggoneers?? If so, how common are they? That would be a lot simpler to do.

Neck -

The '80 and newer Wagoneers and Grand Wagoneers had the 727's that the Jeep D300 will bolt up to. Unfortunately they were for AMC 360's, so they have a different bellhousing bolt pattern. I believe the D300 will also bolt up to some of the Dodge 727's, but they have a longer tail housing than the Wagoneer 727's. Ask Rick W. on the 4x4NW list, I think he looked into this when he was putting the KluneV in his Scout.

You might also want a deeper tranny pan, I think there is one available from Mopar Performance for not much money. Hooper was just researching this recently.