No expert here but we have done these before........Late M21. I bought parts from a reputable place not some generic ebay parts. It goes all back together, rotates fine, gears shift BUT the bearing sticks too far out the end. The bearing retainer won't go back on all the way. I know there are different sized gaskets but we are off further than that. The input shaft on the new one appears to be slightly longer. Pics attached. I called the place I bought them from and he said he can see the difference but doesn't know what to tell me. Any ideas?
I'm not going to name the business at the moment until I make sure it's not my fault somewhere BUT he says all of his are the same and has never had an issue. It is a major supplier which is why I am asking. Unless someone knows something I don't (which is extremely possible. LOL) I'm thinking I'll simply have to send it back and order elsewhere. He did initially send me one from an M22 and I haven't received a refund on it yet. He quickly sent me out another but charged me for it.
I have put together a few M21s and have never seen that issue.........but, I use all NOS parts (in GM boxes), not aftermarket parts.
Have you measured all sums from the other direction? Perhaps beveled end for synchro is where things are off.
Everything goes together good. It's just the bearing sticks too far out. It rotates nice and smooth. The gears all engage as they should. There are no gaps anywhere. I wish I had taken pics before it was taken back apart.
Are you certain it is the correct application ? Several dimensions look wrong just by looking at it,,,,,the area where the bearing sits looks narrow. And even the threads for the locknut look like the wrong pitch ? Tommy
I'm agreeing with Tommy and squirrel on the cone height and the bearing race, not sure on the thread pitch but the length of the threads is suspect to me.
How much was the bearing sticking out of the case? Actually, isn't their a snapring on the front bearing that goes tight to the case under the retainer? How much of a gap is their between case and the snapring? Might be excessive tolerance stack-up.
There should not be any gap between the bearing snap ring and the case. If there is, the syncro ring is either bottomed out on the gear or the main drive is hitting the main shaft. Are you sure the rear bearing and snap ring are fully seated in the mid plate? The syncro ring register does look longer and the overall height looks taller in the photos? When you install the front bearing retainer on the trans without a gasket and snug it up, is the 4th syncro locked up? If it is then either the main shaft is too far forward or the main drive is too tall. Also that's likely a Korean main drive gear, due to it having back cut engaging teeth. That gear should be really used with the back cut Torque Loc style slider also. All of the way better Italian (Auto Gear) gears that I have seen, do not have the back cut engaging teeth, like OE and should use an OE style straight cut slider. If the bearing snap ring is bottomed out on the case and there is play in the syncro ring, and the main shaft will easily turn independent of the main drive, in neutral, then the most likely cause for the bearing retainer being too far away from the case is, the new bearing snap ring has too large of an OD and wont fit the snap ring register in the bearing retainer. Use the original snap ring. I see that all the time. Bill
I'm not 100% certain of anything. It ordered it through The gearbox. I saw where they had been recommended. I didn't order online. I called. I told them what I had. He originally sent me an M22 input. OK, things happened. I called back and he sent me this. I sent them a pic and he acknowledged it was different and simply said "I don't know what to tell you. maybe you can have it machined". I wanted other opinions before calling back.
We considered everything. I'm over a 1/16 or so. It operated really smoothly when together and the gears engaged just fine. You just couldn't put the end bearing retainer on. Just to make sure before calling I think I'll put the original back in and see if it all fits then.
I don’t think I would have it machined,,,,,,I would ask for my money back . Something just doesn’t look right about it . I bought a new pilot for my BW T 10,,,,,it was almost a duplicate of the old one,,,,,looked great . Also,,,,,several gears as well,,, top quality . You might have to keep looking for a supplier . Fit and function on transmission parts is very important,,,,at least to me . Tommy
I get stuff from the Gearbox. He is the only one who will tell you where the parts come from that I have found. I have never had a problem with them. That said, there is always a possibility of miss machined parts. The height difference is not huge. Usually there is a lot of clearance in the 4th sycro , that I would think would compensate for the difference in height. When you snug up the retainer, is there slop in the syncro ring? If not then the problem is there. If there is slop, then the only other explanation is the main shaft is hitting the main drive. Possible that the bore in the main drive is not deep enough? Never seen that before but anything is possible. Bill
The guy who fixed mine a few years back used what is known as "italian gear" sets. Maybe that is a better option. Shoot Paul at 5speeds an email, he's good at getting back with answers.
Just documenting in case anyone else runs into this. We have checked everything. I'm getting ready to call to send this back. I'll call the guy in Kentucky but with bearing installed you can see the difference.
So....it must be something else at least also........we put the old shaft and input shaft etc back in and it's still to tight. It may be closer but when you put the bearing retainer on and tighten it, it locks things up.
Okay,,,good to hear this information . It does sound like something is not seated correctly in the main shaft area . I would go back and strip the entire main assembly down and look it over. If you want to keep the pilot and grind the cone area down,,you could . However,,,I would want an assurance from your supplier that you would not be responsible for the result . I know these parts are fairly expensive,,,I’m guessing 150 or better,,,,,? If you don’t feel comfortable grinding it ,,,I can’t blame you,,,,I wouldn’t either . It’s a brand new part and should be closer to spec then that . Tommy
The outer snap ring on the rear main shaft bearing has to be rotated correct to seat proper in the mid plate. Edit, after looking guess that isn't so.
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