Muncie rebuild question

[Donald H.]

I'm hoping Tom Parsons or anyone who has used the D & L Transmission rebuild kit can answer this.

The oil slinger washer that goes on the input shaft that Larry provides has an indented center (see picture). I need to know if the indention (bumped out area in the center) goes against the 4th gear face or against the back side of the front bearing?

Thanks,

DonOil Slinger washer.jpg

[Tom P.]

Re: Muncie rebuild question

The indented area goes against the 4th gear.
Additionally, you can add ONE (NOT two) shim between the bearing and the oil slinger. Larry always installs shims in his rebuild kits.

[Donald H.]

Re: Muncie rebuild question

Thank you Tom.

[Donald H.]

Re: Muncie rebuild question

The indented area goes against the 4th gear.
Additionally, you can add ONE (NOT two) shim between the bearing and the oil slinger. Larry always installs shims in his rebuild kits.

Tom, the kit I got did not have any extra shims in it. What does adding another shim actually do? Does it just push the input shaft/gear closer to the main shaft?

Thanks,
Don

[Wayne M.]

Re: Muncie rebuild question

Speaking of shims, here's an M22 input gear on the left. IIRC, the shim was marked .037"; the slinger raised center was facing the bearing, not the gear (I understand this may not be correct). The M21 on the right had no slinger and the brass shim is .048" thick.

[Patrick B.]

Re: Muncie rebuild question

Wayne--- The shim on the M22 looks like a rear end shim and the brass shim on the M21 looks like an aftermarket cam sprocket wear spacer. The 1967 Chevy Overhaul Manual does not show any shim between between the gear and the bearing. The parts book does not show any shims for the Muncie 4 speed, but it does show something that might be similar on T-10 4-speeds. However, the T-10 shims were not between the bearing and the gear but rather between the bearing and a forward snap ring (which I guess takes the place of the Muncie bearing nut).

Are you sure these shims are not some kind of hot rod modification rather than original parts?

[Joe L.]

Re: Muncie rebuild question

Speaking of shims, here's an M22 input gear on the left. IIRC, the shim was marked .037"; the slinger raised center was facing the bearing, not the gear (I understand this may not be correct). The M21 on the right had no slinger and the brass shim is .048" thick.

Wayne------


As far as I know, the slinger was first used for 1968 model year Muncie transmissions and then used for all Muncie variants thru 1974. The slinger was originally GM #3916111 and later GM #3925692, the latter being discontinued without supercession more than 25 years ago.

I know of no shims as-shown that were used as part of original Muncie assembly. If there were any such shims used, they were never available in SERVICE from GM.

[Tom P.]

Re: Muncie rebuild question

For a Muncie------------NOT, repeat, NOT a T-10, the addition of a (pinion) shim (.030-.032) is good to do during a rebuild. IT IS NOT, repeat, NOT A FACTORY PART FOR A MUNCIE!!!! Nor, is it a "hotrod" modification. By installing a shim (in addition to the oil slinger) BETWEEN the front bearing and the input gear, the input is moved deeper into the 3-4 synchronizer, thus assuring a somewhat more secure engagement. Most, if not all, of the transmission rebuilding suppliers for Muncies include the shim in their rebuild kits, and recommend installing it between the front bearing and the input gear. I have followed this recommendation for the 40+yrs that I've been rebuilding 4spds (mostly Muncies) and there have NEVER been any issues arise. NONE! Also, on MOST Muncies and T-10s that I rebuild, I also replace the stock synchro sliders with Torkloc sliders. The additional machined back cut in the splines of the slider help to keep the slider pulled tighter into the engagement teeth of each gear, which greatly reduces the possibility of the tranny popping out of gear. This is an especially good upgrade for trannys which have worn engagement teeth.
Below is a comparison of a Torkloc slider (left) and a stock slider. The additional machined back cut in the splines of the Torkloc slider can be seen clearly.



DO NOT, DO NOT, DO NOT add a shim between the front bearing and the input gear on a T-10!!!!! DON'T DO IT!
If a shim is added to a T-10, it causes the input shaft to apply pressure to the main shaft which USUALLY will cause shifting problems, PARTICULARLY 2nd gear! In fact, if a shim is added to a T-10, it may be nearly impossible to shift into 2nd gear.
As mentioned above, a spacer is installed BETWEEN the front bearing and the front snap ring--------------that's all.

[Joe R.]

Re: Muncie rebuild question

Tom,

I've used the Torkloc sliders on the T-10's and never had a problem.

Thanks for the great advise and experience.

JR