Munci help (again!!!)

[Jim K.]

First, thanks to all the replies on my original Munci question, but I need more help. My original posting was after I tried to seperate the tail section. I tried to get it back together before removing the whole unit and had no luck. I now have the munci out and tried to make it close. In short, I have the thing all apart and a few small peices bouncing around, namely:
1) 17 loose roller bearings with a cage toward the front I think I can reassemble with grease to hold them together and
2) 3 - 1" long keys for lack of a better term that I have no idea where they go.
3) there is a washer/shim that sits under the reverse gear in the main case that I bent trying to close the case before I removed the whole unit, how chitcal is that being perfectly flat?
4) with the tail section off the main case, I sliped it over the yoke and there is more play in there than seems possible, like in the 1/16 to 1/8" range not 1000th's, what should I expect?
If someone could forward me a munci exploded view or point me in the direction of a manual, I will still try to put it together myself, but may bring it to a trans shop nearby who I have some faith in....
Thanks!!!
Jim

[William C.]

Re: Munci help (again!!!)

The keys fit between the slider that engages the gear and the hub that it slides on, There are two large round springs that fit into the hub to keep potward pressure on the keys. The keys engage the brass ring that is the clutch in the synchronizer. Any GM service manual or Motors manual from the '64-69 era will geive you information on the assembly.. The washer should be perfectly flat, and it comes as part of a "small parts kit", readily available from many vendors at about $25-30 for the kit. From the play in the rear you describe, it is likely you will also need a new rear bushing that presses into the tailhousing, and a new rear seal as it must be removed to install the tailhousing bushing. Patience, a little time, and a reference manual from the era (all the Corvette shop manuals also show the trans assembly0 will get you thru. If you don't feel comfortable, the local shop should be able to do the job.

[Joe C.]

Re: Munci help (again!!!)

Jim:

Please get it reassembled by a reputable transmission shop. If you assemble it incorrectly, and then run it, you will possibly damage/destroy parts which cost much more than the price of a rebuild.
The roller bearings and cages are for the idler/cluster gearset shaft, aka "the pin". There is a trick to installing these, which involves sliding a wooden dowel through the maincase in place of the "pin". The keys, as you refer to them, are for the synchro sliding collars, three per collar.
The Shop Manual for your Corvette has some very good exploded views, with good text to help you. If you are unsure, then, again, I suggest that you get it done by a pro. Some good vintage trans shops can be found in the Driveline, the Corvettes at Carlisle advertiser index, or Hemmings.

Joe

[Dennis D.]

Re: Munci help (again!!!)

Where did you find the tolerence for shaft endplay? Or , what is it.

Don't know where you live, but Ed Hartnett rebuilt mine a few years ago. Believe he's familiar to NCRS. Did a great job. He's in the Philly area. Good luck.

[Terry F.]

Re: Munci help (again!!!)

The chevrolet shop manual will go through it step by step. You should not have to force anything back together. You need to be confident it is right or it will explode ($).

[Joe L.]

Re: Munci help (again!!!)

Jim-----

The 17 "loose" roller bearings are likely for the input shaft-to-main shaft junction. They fit into the recess on the inner end of the input shaft. These bearings have a larger OD than the needle bearings used for the cluster gear and can be so-distinguished. Also, these input shaft bearings do have a cage. However, the cage is only on one side, so the bearings are not "captured" and can end up appearing as loose bearings. The point is, that you should also find the cage for these bearings and need to reinstall it properly with the bearings. It may still be in the input shaft.

The reverse idler gear uses TWO washers, one on either end. The front washer is GM #3834739. The rear washer is GM #3774909. I would want these washers to be perfect. Both are still available from GM. Also, you can get them with transmission rebuild small parts kits as Bill mentioned. A transmission rebuilder might sell them to you seperately, too.

In order to do this job right, you MUST obtain and use a Muncie rebuilding guide. This can be found in the Chevrolet Service/Overhaul manuals in the year range that Bill mentioned. Manuals are cheap; mistakes made for want of one can be VERY expensive.

[Jim K.]

Re: Munci help (again!!!)

Thanks all, I'm getting there, I understand a whole lot more now!!! I usually know my limmitations and don't push them too far (except this time). I'll let you all know how I make out. Thanks again!!!
Jim

[Tom P.]

Re: Munci help (again!!!)

Jim,
I don't know where you are located, but if it is close to the Okla City area, you can bring it over here, I will put it all together while you watch and explain how/why everything goes where it does (too bad people's location is not included in these posts).

[Jim K.]

Re: Munci help (again!!!)

Tom, I appreciate your offer, this is what I like best about this group!!! Unfortunately for me, I'm a RedSox and Patriots fan (well... I guess it's not so bad right now) I'm in the Boston/Providence area and Okla City is a stretch for me. I really do appreciate your offer though. Thanks!!!
Jim

[Michael H.]

Re: Munci help (again!!!)

Jim,

If you can't find a GM or aftermarket overhaul manual, I can scan and send some or all of the pages on 4-speed overhaul from mine. There are only eight pages which cover the entire build. I consider it required reading if you're new to this.

Michael

[Terry F.]

Re: Munci help (again!!!)

Tom,

You seem to be a great resource for muncie information. I have a wide ratio that was taken from a car back in about 1971. It has a broken counter and input gear in it. The rest of the gears are near perfect as far as I can tell (engagement teeth look perfect, nothing chipped and the cluster gears turn free on the shaft). I would like to put it back together as a project. Can you recommend a source for these gears I need. Also, are the reproduction gears that are out there (from Italy) as good as original? I remember when I took this transmission apart it had automatic transmission fluid in it, also the counter shaft gear had a gear shaped plate rivetted to the front of it, the input had a thin round plate on the front of it that was located between the input shaft bearing and the flat surface of the input gear. Any comment on those would be great. Thanks in advance, Terry

[Page C.]

Re: Muncie help (again!!!)

Hi Terry,
This is the way all of us who do work on your own cars learned. This is a very doable project with the GM service manual.A great source of Muncie parts and info in your area is Larry Fischer.
D&L Transmission
180 W 19th St.
Huntington Sta. N.Y.
11746
(516) 351-4837
Hope this helps,
Page Campbell

[Terry F.]

Re: Muncie help (again!!!)

I have no problems pulling a muncie apart and putting it back together. Essentially, I have a very very nice transmission that I would like to make whole again. I prefer putting new gears in it versus some gears that have a million miles on them. I would like to know how the repro gears compare in quality to the NOS stuff. Also, there is some variablity from year to year all though it is not much. I have heard of people taking the dampener/stamped steel plate off the counter shaft and reasembling it without it because it causes problems, etc. Terry