Borg-Warner T-90 Transmission

Note: For a How-To on rebuilding a T-90, see Rick Stivers guide.

I will simply show you a few pictures of my rebuild, and comment on a few unique things I learned about my transmission.

1. The number one problem most people seem to have with their transmission is it popping out of second gear. Next is hard shifting into second gear. Next is noise. Replace second gear and either the whole syncho assembly, or at least the blocking rings if you are popping out of second. This is caused (mostly) by a worn bushing in second gear. Hard shifting will be fixed by the synchro replace/repair, and noise will be fixed by new bearings all-around.Also do not forget to replace the pilot busing in your crankshaft. A worn pilot bushing, will have you fixing your T-90 again real soon. :-)
   However, This jeep came to me not running, I have no real driving experience with the tranny. So I evaluated the parts and made my best judgement. Second gear felt perfect, the cluster gear shaft was worn, bearings needed replacing. That's about it. I suspect that this transmission was repaired at some point in the jeeps history.
2. Use the ziplock baggie-in-hot-water method to heat the bearings. They will slide easily onto the shafts. See Ricks guide for details.
3. Wire the mainshaft as shown so it does not fall out while you are trying to fit it to the transfer case.
4. do not forget to use non-hardening gasket paste on all bolts that go thru the case.
5. Use spray-on Permatex for the flat gaskets.
6. Be careful of the OEM rebuild parts that comes from the willys dealers. I was not able to use the snap ring on the end of the output shaft, synchro springs, reverse idler shaft and countershaft. All were dimensionally incorrect. I reused my old parts, except for the shafts which were purchased from Novak Adapters.
7. Bearings    Front: NACHI 6208N C3      Rear: SKF 65307

Here's our nice boiled clean case, painted and ready to go.....

Well I left out a few steps here :-) , but we're done.

Another view of all those pretty gears and such...

Here's where I made on bad mistake. Note these two Shaft plates. The thin one came out of my transmission, and the bigger one came from the rebuild kit.

I mistakenly assumed (danger, danger!! Dr. Vern) that I could replace my old plate with the new one. BUT, look at the subsequent photo's to see why you cannot. The Transfer case is relieved to only to fit over the skinny plate. I guess there are a couple versions of the D18. So be aware of this.

More details on the two plate types.

In the end I was able to modify the larger plate to fit into my case. Good thing, cause otherwise I would have had to take it apart completely in order to drive out the rear idler shaft to re-orient it.

The finished T90/D18 assembly. Note I left the levers and shift tower off. I think this will make installing the tub easier when the time comes, we'll see.