C2 tranny out - should I do anything to it?

[Timothy B.]

Its been awhile since I have touched my 67 or posted on this board. Glad to be back. Hurricane Rita prompted me to evacuate the car out of Houston, and in the process got me going on some work on the car.

The goal is exhaust pipe and tunnel insulation replacement, the latter of which requires me to take out the M20 Muncie tranny. Question is, which tasks should I consider performing on the tranny (or anything else down there) while I have things apart? The tranny makes no abnormal noises that I am aware of. I had it out in the early 80's (but probably only 10 or 20K miles) for clutch, throwout bearings, fork, ball, etc. replacement. The tranny has never been worked on internally as far as I know since we got the car in '75, but seems to work fine.

Any suggestions would be appreciated.

[Joe L.]

Re: C2 tranny out - should I do anything to it?

Tim-----

How many miles are on the transmission?

[Timothy B.]

Re: C2 tranny out - should I do anything to it?

Probably around 80K would be my guess.

[Timothy B.]

Re: C2 tranny out - should I do anything to it?

The only noise that the tranny makes is a light whine when the clutch is engaged just sitting there idling with the tranny in neutral. I have asked about that before on this and other sites and folks seems to think that was normal for a M20. I think that as a minimum, I will replace the pilot and throwout bearing while I have things apart. I will inspect the fork and ball, and clean and relube as required. I have determined from records from my work in the 80's where I replaced the fork and ball and that I installed the correct parts (thanks for earlier responses from Joe :-) Clutch action and feel seem just fine.

[Joe L.]

Re: C2 tranny out - should I do anything to it?

Tim-----

If the transmission works ok and your're not planning on putting a lot of miles on the car, I think that you could leave it as-is.

[Stephen L.]

Re: C2 tranny out - should I do anything to it?

You may want to replace the seals on the shift fork shafts. They are cheap, but they are also old and possibly deteriorated.

[Stephen L.]

Re: C2 tranny out - should I do anything to it?

You may also want to clean and lube the shifter mechanism and check for worn parts.......

[mike cobine]

Re: C2 tranny out - should I do anything to it?

If you have leaks at the shifter fork shafts, then change those. If you have a leak at the trail on the output shaft, then change that, also.

Otherwise, I'd leave it alone other than maybe change fluid, if it is dirty.

[Larry S.]

Re: C2 tranny out - should I do anything to it?

I am not sure what the going price of a rebuild these day are. But thinking you plan on keeping the car a while an knowing what a pain in the put it is to pull the trans.

I would suggest.

Sending the tranny to Ed Hartnett 4 Speeds 242 Penbroke Ave. Lansdowne, Pa. 19050 (610) 623-9381 I used him to rebuild the trans out of my 66 and he was a pleasure to deal with. He only replaces whats needed.Mine seamed to be working fine but had a leak in the front that I could never correct.I forgot what it was called but he had to rebush the fron of my case thats where my leak was coming from. that also tightened up the trans quite a bit.

I would also look long at hard at the clutch and assoceated parts.

Check U joints on the drive shaft.

All of the bushing with the Z bar

Condition of the trans mount.

And just some advice if you do change the clutch. Use a borrowed input shaft to align the clutch (Ed will loan you one when he ships you the trans in his shipping container).Check the size of the pilot bearing to your input shaft before you drive it into the flywheel Connect your clutch pedal and have some one depress the clutch when your 1/2 to 1 inch away while slightly rotating your trans and pushing foward to bring the trans home to its mating surface on the bell housing.

Allthough you dont have the same problem as I did " A Leak" I had my trans in an out about 5 times with in a 3 month span trying to fix/correct this leak untill finally some one from this board suggested I send it to Ed.Some of the best money I have ever spent on my car.

Good luck and be safe

[Joe R.]

Re: C2 tranny out - should I do anything to it?

I agree with Larry! While that trans is on the ground it should be disassembled, cleaned, inspected and a new seal kit installed including the shifter shaft seals (GM part number 3831716) replaced.

Eighty thousand is not a lot of miles but a quarter mile at a time could destroy the trans in one pass.

A rebuild kit for that trans that has seals, rings, bearings and counter shaft if less than $200.00 and would be cheap insurance. It will cost more than that to pay someone to pull it again.

JR

[don 42616]

Tim, The whinning sounds like the throwout bearing *NM*

[Timothy B.]

Re: Tim, The whinning sounds like the throwout bea

Well, the slight whine I hear is only with the clutch disengaged (released). I thought that if it were the throwout bearing it would make the noise with the clutch depressed not released?

[Michael H.]

Re: Tim, The whinning sounds like the throwout bea

Just my opinion but, if the transmission operates properly and has no "issues", I would probably put it right back in without a rebuild. Fixing things that aren't wrong usually starts a chain reaction of problems that only more money can cure. At the most, I would consider a new front bearing and rear seal. A rebuild can be a VERY expensive ordeal these days and in the end, the unit won't be any better than it is right now.

[Timothy B.]

Re: Tim, The whining sounds like the throwout bea

What is involved in front bearing replacement? Is that something I should be able to do myself with the tranny out? Special tools required?

[Michael H.]

Re: Tim, The whining sounds like the throwout bea

There is one special wrench required. After the front bearing retainer is removed and the front bearing is visible, you will see a very unique nut that retains the bearing to the shaft. There are only two very thin "flats" on this nut and it requires a wrench made for just this operation. Perhaps there's a transmission shop near you that allow you to borrow one. (caution, LEFT HAND THREAD)

Once the special nut is removed, it's just a matter of tapping the front of the input shaft rearward and removing/replacing the bearing.

There may be a pic of this operation in the GM overhaul manual, if you have one.

Don't over torque the four bolts on the bearing retainer when reassembling. If I remember correctly, that value is only 20 lb ft??