Please identify this mystery part for me

[BlueCorvette]

Hi everyone, I recently acquired a 1985 4+3 that, you guessed it, needs work. I was disassembling the drivetrain, when I noticed that there was a washer floating on the transmission bottom, visible through the manual transmission drain hole. I removed it through the side cover. It's dimensions are: 1.623 OD, .034 thickness, .886 flat to flat on the ID hex shape.

Can somebody ID this for me?

My guess is it could be a washer from the reverse idler gear. Thrust washers I see with slots and tabs, this one is just flat. You can see the gap in my gear pic. Looks like something should be there from the T10 parts diagrams I have seen. Transmission serial matches VIN, got car from my family, 1 owner. No transmission rebuild, but the O/D unit was worked on. Could this be from the original factory build?

Here are two pics. The washer, and the reverse idler gear.

Any help would be appreciated, thanks

 

[forrest]

Hi everyone, I recently acquired a 1985 4+3 that, you guessed it, needs work. I was disassembling the drivetrain, when I noticed that there was a washer floating on the transmission bottom, visible through the manual transmission drain hole. I removed it through the side cover. It's dimensions are: 1.623 OD, .034 thickness, .886 flat to flat on the ID hex shape.

Can somebody ID this for me?

My guess is it could be a washer from the reverse idler gear. Thrust washers I see with slots and tabs, this one is just flat. You can see the gap in my gear pic. Looks like something should be there from the T10 parts diagrams I have seen. Transmission serial matches VIN, got car from my family, 1 owner. No transmission rebuild, but the O/D unit was worked on. Could this be from the original factory build?

Here are two pics. The washer, and the reverse idler gear.

Any help would be appreciated, thanks

There should be a flat spacer/shim in the place you are showing the shims with tabs and groves cut in the face go by the counter shaft in the bottom of the trans. your shim can be fairly easily installed if you have the trans. out for a clutch or some other repair it just requires splitting the O-D case from the T-10 and a gasket between the two parts.

you indicate that the O-D has been worked on well that is when it fell out, when you separate the two the shaft that holds the Reverse idler is removed leaving the part free to roam. best way to put the two back together is to find a old car rim with a good offset ( like a Corvette ) put the input shaft thru the rim and make a stand have Trans pointing up have your shim in place line up all the the parts (make sure you make connection of the reverse gear and slide between the cases) wiggle it all together put bolts in (Lightly tightened) and confirm that the reverse linkages are working if not now is the time to find out. if all is well tighten the bolts the rest of the way

 

[BlueCorvette]

Thanks, that makes sense. It doesn't seem to cause any problems, but I will pull the O/D unit off to make sure all the parts are on the idler gear and reassemble.

 

[BlueCorvette]

I removed the O/D unit. On the reverse idler shaft, front to back, gear, reverse idler gear w/ snap ring, bearing, washer.

I tried to put the washer on the 1st gear, but the ID is too small for the front end of the reverse idler shaft to slip through. This pushes the idler gear out just enough that the O/D won't seal back to the manual.

So it's not the front washer. I think that the same problem would occur if it was in front of the bearing, like washer, bearing, washer. From above you have the bearing riding on the surface of the rear of the idler gear, and a washer on the rear side.

So I'm at a loss as to where this goes. I'm thinking that when the O/D was serviced, they had a bunch of parts that would have worked for the different styles of T10 reverse idler gear assemblies, and this washer got dropped in somehow. I still think it's missing that front washer though.

 

[forrest]

I removed the O/D unit. On the reverse idler shaft, front to back, gear, reverse idler gear w/ snap ring, bearing, washer.

I tried to put the washer on the 1st gear, but the ID is too small for the front end of the reverse idler shaft to slip through. This pushes the idler gear out just enough that the O/D won't seal back to the manual.

So it's not the front washer. I think that the same problem would occur if it was in front of the bearing, like washer, bearing, washer. From above you have the bearing riding on the surface of the rear of the idler gear, and a washer on the rear side.

So I'm at a loss as to where this goes. I'm thinking that when the O/D was serviced, they had a bunch of parts that would have worked for the different styles of T10 reverse idler gear assemblies, and this washer got dropped in somehow. I still think it's missing that front washer though.

with washer in hand does it slip over the reverse idler shaft? (the stainless bar mounted to the O/D) it should unless it a wrong part, I will grant you that I am doing from memory from things I have not needed to do since the real early 90s. there should be a Needle baring pack with race by front cover of O/D (the stainless shaft) goes thru it and the reverse gear the washer should sit inside the case and wiggle together, there should be no Snap rings to removed for this job.

so first does the shim slide over the shaft?
is the trans. pointing up with Input shaft down and output shaft pointing at the sky. if not the shim will not line up to easily and fall out of position.

 

[BlueCorvette]

I didn't notice before but the front bronze bearing of the two in the gear shaft had walked out and was keeping the front thrust washer that I found from seating correctly. Probably started walking out when they reassembled with the washer missing. That is what is keeping everything from fitting together now.

I need to press the bronze bearing back in, but using moderate pressure in a vice did not work. I don't want to deform the bearing, it rides on the inner shaft. It is a thin steel cylinder with a bronze cylinder inside. if necessary I could grind off the protruding part. It's only a fraction of an inch out, just enough to screw up the reassembly.

 

[BlueCorvette]

Here is a pic of the front side of the reverse idler gear with the bushing coming out. You would think I could press it back in, but I am afraid of damaging it.

 

[forrest]

Here is a pic of the front side of the reverse idler gear with the bushing coming out. You would think I could press it back in, but I am afraid of damaging it.

Looking from the other end can you see were it has moved away and left a void, as for pushing it back I think it would take more force then a household vise could give, it is safe to say that is on of those things that is assembled with heating and liquid Nitrogen. If the evidence shows it has slid I would say you need a good Machine shop that has the Know how or the force needed to do the job or see if you could locate a new one.

 

[BlueCorvette]

The bushing is about an inch long. I can see a circular scratch on the inside of the shaft about where the other end would have been pressed to originally. I probably need to take it to get pressed in for a few dollars. It have heard elsewhere that the bushing should not be that tight a fit. Thanks.

Update:

I got a loaner ball joint press from the auto store and it pressed in with little effort. My vice is weak. It's all reassembled now. Thanks everyone.