Transmission Main Drive Gear A-7017
 

I am installing the transmission and find that the pilot bearing just slips on the shaft. While the bearing isn't sloppy on the shaft you can turn the inner race on the shaft. There is no interference fit. Are there any tricks to shim up the shaft just a bit so the pilot bearing is snug or is this shaft toast? Driving the car last summer, there was no problem with the transmission. Thanks for your help. Ed

Re: Transmission Main Drive Gear A-7017
 

Your pilot bearing fit should be snug, no more than .002 slop. If it's loose you'll get transmission growl, trans popping out of gear, and poor gear alignment. For all the trouble to pull a tranny, I'd replace the shaft if you have any doubts.

Re: Transmission Main Drive Gear A-7017
 

You can use Locktite or use a center punch to make a lot of small dimples where the bearing fits. If it's assembled in the tranny and you use a punch, then use a heavy plate for backup as you center punch the dimples.

Re: Transmission Main Drive Gear A-7017
 

You can have the pilot end of the shaft re-sleeved for a nominal cost. Contact Jim's Automotive services in Costa Mesa, CA 714-546-2969. Jim will machine the worn area and press a sleeve over it.

You want a nice sliding snug fit, not an interference fit as it would make installing the transmission difficult.

Tom Endy

Re: Transmission Main Drive Gear A-7017
 

While were discussing this gear, I was wondering if anybody has come up with a fix for the opposite end. I just dismantled a transmission that had almost no apparent wear on any surfaces except for the bearing pocket where the mainshaft goes in. The needle bearing had somehow brinnelled a series of longitudinal grooves into the outer bearing surface. Since a new open needle bearing will only resume that wear pattern, I was wondering if there might be a jacketed bearing that might be used as a replacement? The jacket or bearing cage would eliminate any problems resulting from the grooves because the jacket would form the new running surface. Any thoughts?

Re: Transmission Main Drive Gear A-7017
 

I haven't a good fix for the pocket end but you can turn down the pilot end and use a 203 special bearing on it, undersize id for the turned down pilot. You I have a 203 pilot tool I use for clutch setup. It workes pretty slick... mark the input shaft somehow so that anyone who gets into it knows not to try a stock trans input shaft into the undersize pilot.
Larry

Re: Transmission Main Drive Gear A-7017
 

Thank you for all your suggestions, Ed

Re: Transmission Main Drive Gear A-7017
 

I would either grind and sleeve the pilot, grind and use a smaller ID bearing, or replace the shaft. The costs of sleeving or replacing are roughly equal. Its a bit cheaper to use a smaller ID bearing, but can present a problem later when you need to replace the tranny with another for any reason. I would not use locktite. Imagine trying to pull the tranny later on if the locktite has a good grip on the bearing. Don't ask me how I know this.