Bob's Studebaker Resource Website


Bob Rausch, Missouri SDC member

Rebuilding T86E Trans. Part 1--Cluster Gear

Some time back I posted about needing to rebuild a Studey T86E 3-speed O.D. trans because of a chipped 1st-Rev sliding gear.

So I found a good NOS sliding gear on ebay for pretty cheap, and got it. I intended on only replacing that gear and not replacing the cluster gear, even though the cluster also had a very small chip out of one of the teeth. But you know how it is... I kept looking at that chipped tooth on the cluster, and then the guy I bought the sliding gear from, who also had an NOS cluster gear and a rebuild kit made me an offer I couldn't refuse. So for a little over $170 I got the NOS sliding gear, the NOS cluster gear and a rebuild kit that had all new bearings (Japanese, Nachi brand) new synchros, new seals and two gasket sets.

First I separated the OD case from the T86E case, and pulled out the old cluster gear. In doing so I discovered that this trans had been recently rebuilt. If you've ever taken apart a 50-60 year old trans you know what I'm talking about--black gooey crud! But this trans looked clean and pristine on the inside, and the gear lube looked clean and new. My guess is that somebody rebuilt the trans, and then somebody chipped the gears.

Here's the NOS cluster gear on the right, and the original behind it lying flat. The crud on the outside and bore of the gear is just that--crud. It's not rust, and it later cleaned off.

But wait. Notice the facing end of the NOS cluster and notice the facing end of the old one, visible in the next picture:

Notice the small slots milled into the facing end of the old gear.
What to do?
The thrust washer that goes against that facing end has two little bent tabs that fit into those milled slots. I can either bend those little tabs back down, or grind them off, or cut some new slots into the NOS cluster gear.
I don't want to bend them down, because the final tolerances need to be .005 to .017 thou. and I know trying to bend them will cause some distortion in the thrust washer. I don't want to grind them off--they're there for a reason... so I decided to cut some new slots.

Here are the new slots I cut, and you can see I've put 22 new rollers in the bore too, set in grease for easy of installation.

Next I put the remaining 22 new rollers into the bore on the big end. The wooden dowel is a faux-shaft that I'll keep in place while placing the cluster into the case. Then I'll use the real shaft to push the wooden one out and in the process keep everything in place.

Which is what I'm doing here--pushing the faux shaft out with the real one.

Here I've got the real shaft in position and locked in with the flat.

Here's a picture of the case before I cleaned it up. Very, very clean on the inside.

Here's the rebuilding kit I got on ebay. To it's right is the original input shaft and it's bearing.

(Next) week I'll mate the O.D. unit and mainshaft into this trans case and post about that.

And the original cluster isn't too bad at all.
Here is what it looks like:

Here's a close up of the damaged area. I was going to re-use it until the offer came through to get the NOS cluster.

Comment

OK... round II. I installed the new 1st/Rev sliding gear onto the mainshaft.

Got a nice new gasket out of the package and slipped it on:

Slid the mainshaft and OD unit into the main case, and got the 14 little
rollers installed into the input shaft and slid it in from the other end:

Then I mated both shafts together.

And I tried to install the oil slinger and the front input shaft bearing. Long story cut short, I couldn't get the bearing seated because the oil slinger wouldn't seat--it wouldn't work because it was abnormally dished too concave. Don't know how that came to be, but I suspect the previous owner of this trans assembled it incorrectly when it was rebuilt--this was not the only thing I found wacky on this trans. So I pulled the input shaft and removed the mainshaft/OD unit from the main case and went to my rat-hole and dug out another T86E input shaft that had the correct oil slinger on it. However that was Fri. night, and so I had to wait until yesterday to get that bearing pressed off. Got the bearing pressed off and in cleaning up the main case etc. I noticed I only had 13 of the input shaft rollers. Now where had that 14th roller gotten off to? I checked the main case and the tabletop and the floor and the walkway into the house and the kitchen floor and my shoes.

.. I eventually located it stuck into the synchronizer ring. Whew!

So today I stuck the rollers back in:

Mated the mainshaft/OD and the input shaft together again:

And successfully got the input shaft bearing and oil slinger and positioning ring and the locking ring all in. Got the front cover and gaskets on and stuck the shifter on the top. I still have to "adjust" one of the shift forks, but it's getting there. This will go behind a 259 in my buddy Bob's '49 Studey 3/4 ton truck that belonged to his dad.