TCI appears to be the only one that makes a LONG tailshaft turbo 400. I'm going to try to get ahold of Camaro Bob and see if I can get the trans through Pro Musclecar. I just need to make sure I have the 12" tailshaft and not the 9" one before I order it. Since it's good for 450hp, I should be ok, even with all the torque and weight.
Kind of sucks though, as I'd rather not spend $1100 on a trans. With the broken stuff, it doesn't appear that I'd trust rebuilding this one either.
So this weekend I took a couple sessions and pulled the old Turbo 400 out. I don't have a new trans yet, or even have one ordered, but I figured it had to come out either way.
So after an all day session with 32V, the new transmission is in the car and seems to be fine. But while running the trans through its paces on the jackstands, I came to the sad realization that the noise I was hearing was not a broken transmission afterall. While it was idling in gear, I put my long screwdriver to the rearend to listen, and that's where the noise is coming from. So obviously I'm pretty disappointed.
Now I need to focus on selling the Trans Am so I can afford to put the right rearend in the Caddy because I'm not replacing another one of the junky ones.
Very disappointing. Nothing to do now but move on.
With that thought in mind here is something I found on a Cadillac forum;
Posting question
I have a 1969 deville that i'm looking to swap the differential in. But before i get into it i'd like to know if it was a proprietary differential or if there are other gm diffs that will fit the carrier rearend. Any help is greatly appreciated as it could save me a bunch of time and money.
Answer
Its been a long time since I pulled out spiders and pinions, set backlash, etc .. but ...
An entire rear end from another GM product is a bolt-in fit as long as you're doing it in the same body style. Minor differences such as brake lines and U-joints are the only minor trouble spots. Cadillac, Buick, Olds, and Pontiac rear ends are interchangeable if they are the same frame size.
1964 to 1967 A-body 10 bolt rear axles, with 1968 to 1972 A-body axles, the entire housings will swap.
1964 to 1967 axle is ¼" narrower. But at 1/8" per side means, for all intent and purposes, they are the same.
As a general rule, most of the axle shafts will swap as long as they have the same spline count, excluding 10 bolt "C" axle shafts (Chev) which have an internal "C" clip to retain the axle in the housing and use a roller bearing in the tube end.
The rest have a bearing pressed onto the axle and then bolted to the tube end.
Most GM diffs carriers carry ring and pinion sets up to 3:42. After that (3:73 and up) you have to change the carrier. As the pinion gets smaller with the lower gear ratio, the deeper the crown gear gets. Instead of making extremely thick crown gears, GM made two types of carriers instead.
As for gear combo, say if you had just a posi carrier with say a 2.73 gear, you could put a 4:10 gear or even 4:33 with compatible gears, shim it because when you put higher gears on the carrier, the carrier shifts. These shims go between the carrier bearings and the start of the axle tubes in the housing.
OR, do what I did the last time I swapped .. I bought the whole darn axle with the gear set I wanted, opened it, drained it, washed it with solvent, new seals went on, then I unbolted mine from the car, bolted the replacement axle set, installed new brakes, lines, filled the rear end with 90W, etc .. and off I went. Tools needed for this method? a set of box ends, sockets, chisel, hammer, pliers.
but, getting back, the year was 1969 .. 50 years ago .. your car has what in it?
you dont know .. for all you know, the rear end has been changed or retro or mod or fixed or ????
also, that is about 4 years before big government jumped in and started telling the auto industry what to do with the drive trains so .. there were not many rules, or at least, not many when it came to the drive train. In those times, people that knew next to nothing about cars, would pick up parts at their local yard and drag them home, made them fit.
And THAT is my simpler answer .. hit the pages of Craigs or search the huge yards of vintage cars in the deserts (Arizona, Nevada, New Mexico, etc...) for vintage rear ends of that era of similar body size of your car .. open it up, inspect the teeth, calculate the gear ratio of the, drag it home. If you should make a mistake, do***ent what you got, rations/condition/car body, put it on Craigs for the next guy doing a project.
Its a project, right? In a project, anything (almost) is a possible solution.
This isn't an a-body so that doesn't apply here, it's a b-body. This would be only the FULL size stuff like the Electra 225, Olds 98, and the Caddy. I searched all night for a picture of a rearend out of the Buick or Olds, with no luck. I think I'll take a trip to the local yard after work tomorrow to see if I might get lucky. I see a couple options on Craigslist for Caddy rearends, but I really don't think that's the answer.
If anyone has any idea where I can see a '68-70 big Olds or Buick, let me know so I can look and measure.
That Olds rearend looks like the one with the same LOW shock mounts and WIDE upper control arm mounts. I'm probably not driving to NH to get one, and I still need to measure the width, just to be sure. Somehow the Impala, Bonneville, Lesabre are smaller. These are only for the real ocean-liners.
There's a free breakfast in it for anyone that can find one local, faster than me. It doesn't need to be posi, I just need the carcass and I'll put new stuff in there.
After determining there's not a real 12 bolt out there (12 bolt cover, 10 bolt guts) for a true full size car, I figured the only thing left to do is put the 9" that I've stored for years into the car. AKRover might recognize this as the one from his old t-bird. After some measuring, it appears to be 1.5" narrower to the backing plates than the rear in the car, which doesn't appear to be a problem. I measured some angles tonight, and plan to pull the rear out next weekend. Hopefully over the next few weeks I'll be able to borrow Racin' Jacin or his partner in crime, StantheMan, for some plasma cutting fun to carefully remove the mounts from both rearends.