T-96 Transmission Overhaul

by Tom Jennings, 04-07-2020, edited by Frank Swygert 01-26-2026

new ~ 2010

The following was written before I broke two T-96’s without doing anything particularly stupid to them. I’ve since re-assessed my opinion of it, which is now that it might be suitable for the 80 hp of the flat-head six it was first used with, but no more. Certainly not even the 125 hp of the OHV engine. I drove it moderately hard, but generally shifted it as slowly as it wanted (and it is slow), not
crashing gears and definitely not downshifting to first. It’s weak. I will not own a T-96 car again, out it goes. Too bad, as the T96
with OD and the optional second gear ratio was a perfect match gear-wise for the OHV engine.

Frank: Tom’s assessment isn’t far off. I’ve driven t-96 equipped cars more extensively though. For it’s intended use, normal driving for the 40s-early 60s, somewhat sedate by today’s standards, it’s fine. But you can’t push it much. Most of the problem now (and that Tom had) is that the little transmissions are old and have already seen a good bit of “abuse”. I have that in quotations because today’s driving styles are abusive to that trans — it just wasn’t designed for modern driving. Drive it like the average 1950s commuter not in a terrible hurry and it would be okay. Buy it as a cheap used car for a 1960s-70s teen (like my first one) and it’s getting abused! Just drive it sedately and it will last. I rebuilt the HD version (early 70s T-96J – had a slightly larger input shaft bearing and slightly harder material used for some shafts and gears for 232 powered base model Gremlins) with overdrive and used it for 18 months behind a 4.6L stroker (4.0L w/258 crank). The synchronizer lasted about 200 miles before it went, and I was driving carefully. Then it was double clutching to down-shift, but otherwise it was fine. About a year in, roughly 4500 miles, one of the synchronizer rings actually cracked and jammed it in gear. I took the trans out, pulled the main shaft, took cracked ring out, and drove it another six months while looking for a better transmission. When I took it apart the new gear cluster looked like it had 50-60K miles on it, not 4500-5000. It was finally replaced with a Jeep AW4 automatic, as I couldn’t find a Jeep XJ 2WD five speed at the time (in 2000). 

 

The transmission in this little car is the widely-reviled T-96 by Borg Warner. Tales of the frequent failure of this tranny are common, but unwarranted. It’s light duty, but fine in this car.

The real problem is that no one knows how to drive a non-synchromesh car any more, crash first gear, and break off teeth. Simple as that. This isn’t a valid complaint, it’s an old car from another era being driven like a modern car — it just doesn’t work.

I have a T-14, but it has no OD unit, which really makes this car (63 American). It’s a more rugged transmission, and parts are a lot easier to find. Without the OD I set it aside.

I knew the rebuild job would be a big deal; it was even bigger. This is a car from a previous era; it’s not a “60’s” car, it’s a 40’s/50’s car, and all attendant peculiarities.

Some parts were very hard to find, mainly the commonly-broken first gear. The counter gear was hard to find because this has the optional “Twin Stick” second-gear ratio. Twin-Stick models have a big “gap” between second and third gears so second+OD can be used as “third” gear (making actual third “fourth” and third+OD “fifth”). The rest of the stuff was available, mainly seals and bearings.

Assembly was pretty straightforward, and pretty enjoyable overall. I made the tool as suggested by the Technical Service Manual, a .677″ diameter steel rod. No mysteries, no extra parts. There’s a transmission section, and an overdrive section; there’s one section in the
middle that’s not well documented, which is in the overdrive to transmission adapter. I left accidentally out the oil baffle from the adapter; the whole trans had to come apart to install it, but otherwise things went well.

It all installed OK. Assembly of the driveshaft is slightly peculiar, in that the driveshaft slides at both ends until the big nut is tightened. I had the axle dangling by the springs on the rear shackles. Installation requires pulling the axle up and forward to get the front spring
perches back in place. It’s a PITA. I found a simple solution — a nylon web cargo ratchet strap, wrapped around the rear crossmember and axle, and just cranked into place.  (Frank: It’s designed to be put in place with weight on the rear wheels. If jackstands or jack are under the axle or using a drive-on lift this isn’t necessary, only if the rear axle is dangling on the springs. )

The T14 will just about bolt onto the microscopic bellhousing, fits the clutch, and fits the pilot bushing. Need to lower the bottom two mounting holes, a few hours work. So I will watch out for a T14 with overdrive.

Turns out, there are few parts needed to fit an R10 overdrive unit form a T96 onto a T14. You’d need a transmission (output) shaft for a T14 overdrive; somewhat hard to find but specific at least. Bearing, straightforward. Last, bore the back of the T14 case to accept the OD adapter; it would need a hole, concentric with the existing bearing hole, for the adapter. It would need to be accurately bored. The OD/reverse lockout would have to be adapted or sacrificed. But it’s doable…

Dart the dog helps measure the clutch shaft prior to hunting for a new clutch.

Dir-tee tranny! That’s a half-century of use for you.

Yep, first gear teeth busted from someone slamming first gear (down-shifting into first without double clutching or at a stop/near stop).

Walking the clutch shaft bearing out without the proper tool.

Disassembly photos to help reassembly!

Parts after the second washing. A third washing, in lacquer thinner with motor oil added, was required. I hate using solvents but
there wasn’t much choice with this job.

Damage to first gear teeth on countershaft not visible until the third wash.