Transmission overhaul

updated 07 apr 2020

new ~ 2010

The following was written before I broke two T96'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 flathead six it was first used with, but no more. Certainly not even the 125 claimed hp of the OHV engine. I drove it moderately hard, but gnerally 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 T96 car again, out it goes. TOo bad, as the T96 with OD and the optional second gear ratio was a perfect matchm gear-wise, for the OHV engine.

The transmission in this little car is the widely-reviled T96 by Borg Warner. Tales of the frequent failure of this trannie 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.

I have a T-14, but it has no OD unit, which really makes this car. 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 countergear was hard to find because this has the optional "Twin Stick" second-gear ratio. 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 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.

(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.

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

Dir-tee trannie! That's a half-century of use for you.

Yep, first gear teeth busted from someone slamming first gear.

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.