Looked at a parts truck tonite. '71 J-4000, the question is this: what auto tranny should this truck have had, the one that comes with it has a 20 behind it but doesn't look like a T400, but then it doesnt look like a 727 either. looked like a GM with AMC (round with the starter on left side) bellhousing but the pan looked like a T350. It was kinda dark so I may be off base. Any thoughts? Also, the D60 flanged axle 5 lug, would it be likely to be 35 spline?

BTW: I don't actually have the truck yet, otherwise I would go outside and look again.

Look here:
http://www.jeeptech.com/models/jpu.htm

Should be a TH400

in those early years they used a regular th400 with a cast iron ring to adapt it to teh amc engines.

or without the adapter ring behind teh buick engine.

Originally posted by ozarkjeep
in those early years they used a regular th400 with a cast iron ring to adapt it to teh amc engines.

or without the adapter ring behind teh buick engine.

Then how did they mate it to the buick engine? I'm not familiar with the BOP pattern... it's not the same as an AMC is it??? :confused:

the AMC 360 wasn't used til 72 or so. a standard GM bellhousing was used with an adapter ring to mate a th400 to the buick 350. a special adapter was also used to mate the t400 to the d20, which is why these trannies are a hot ticket.

if the th400 is mated to an AMC engine, it will have a special AMC bellhousing (or should, anyway). there might be exceptions to that rule; i've heard of some th400s with adapters to the AMC bellhousing pattern.

the d60-2 is a 35 spline semi float axle.

I have no idea how hte th400 mounts to a buick engine, I just know that before AMC orderedn enough of the trannys to warrent a bellhousing redesign, they used a cast iron ring to adapt a th400 to an AMC engine.

Originally posted by ozarkjeep
I have no idea how hte th400 mounts to a buick engine, I just know that before AMC orderedn enough of the trannys to warrent a bellhousing redesign, they used a cast iron ring to adapt a th400 to an AMC engine.

you might be talkin about the AMC 327. that was before AMC even standardized their own bellhousing. when the 360s and 401s started getting put in trucks, the th400 had an AMC pattern.

The guy I bought it from said it originally had an adapter of some sort on it, but I thought it might have been for an engine swap of some kind. Is it possible that this is a TH-375(yes there is such a thing, though I've never seen one)?

I'm picking up the truck tomorrow. Should be able to look at it in the light, or at least with a flashlight then.

WillyPete,

actually , I was refering to the 304/360/401 series of AMC engines, ive seen a few of them with the cast iron rings and th400s, all very early 70ish rigs.

Turns out the thing is a TH-400, I must have been :smokin: that night.

New question: same guy has a 73 J-10 with a T-18 that he would sell the trans out of if someone else that has already looked at it doesn't buy it, this should have 6+ first gear ratio, right? not the 4.0:1 like my 73 CJ, right?

Originally posted by ozarkjeep
WillyPete,

actually , I was refering to the 304/360/401 series of AMC engines, ive seen a few of them with the cast iron rings and th400s, all very early 70ish rigs.

true true, i've heard of the early 70s AMC engines having adapters :); sorry, slipped my mind :emb:

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if it's a t18a it will have the 6.32:1 first. the t18 with the 4.03:1 first gear came out before 73. best way to check is to pop it in first gear and turn the input shaft. you'll have to turn it about 6 times to get 1 rotation out of the output shaft.

nevermind . . . I'm a dumba$$ who can't read . . .