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A Couple 4speed Muncie Questions??

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Old Apr 9, 2010 | 10:50 AM
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Default A Couple 4speed Muncie Questions??

Let me say thanks in advance...

1. How can you make sure you have a 68-70 Muncie and not a 71-74 ?

2. Can the rear seal be changed with the tranny in the car?

3. What about the bushing right behind it?

Reason I ask is because when I removed my driveshaft slip yoke, the outer area where it would seal looks really worn and bunged up. I

I'm going to replace it... but I want to replace the seal and bushing in there also - to give the new one a fighting chance.

-W
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Old Apr 9, 2010 | 01:54 PM
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Originally Posted by Clams Canino
Let me say thanks in advance...

1. How can you make sure you have a 68-70 Muncie and not a 71-74 ?

2. Can the rear seal be changed with the tranny in the car?

3. What about the bushing right behind it?

Reason I ask is because when I removed my driveshaft slip yoke, the outer area where it would seal looks really worn and bunged up. I

I'm going to replace it... but I want to replace the seal and bushing in there also - to give the new one a fighting chance.

-W
1. Take the numbers off the case and post them or look them up.

2. Yes

3. No
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Old Apr 9, 2010 | 02:04 PM
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1. The stamp for '68 would be P8xxx (month, date) with a suffix A for M20 or B for M21. For '69 it would be P9xxx, for '70 it would be P0xxx, etc.
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Old Apr 9, 2010 | 02:12 PM
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Thanks! Any idea what would cause the driveshaft slip-yoke to look like crap on its outer surface where it goes into the tranny?

-W
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Old Apr 9, 2010 | 02:42 PM
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Possibly an out of balance drive shaft. I know mine looked like crap when I took my Muncie out. I replaced the bushing when I had mine all apart.
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Old Apr 9, 2010 | 02:58 PM
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The rear seal on the muncie is really easy to do while it is still in the car - just be sure to go pick up a seal puller. It makes the job a whole lot easier having the right tool.
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Old Apr 9, 2010 | 05:26 PM
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Originally Posted by Clams Canino
Let me say thanks in advance...

1. How can you make sure you have a 68-70 Muncie and not a 71-74 ?

-W
Front input shaft should be a course spline. With exception of M22 case, there should only be 1 drain plug in main case.

1971 cases have 2 drain plugs and all input shafts are 26 fine spline.
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Old Apr 9, 2010 | 08:49 PM
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Originally Posted by Faster Rat
1. The stamp for '68 would be P8xxx (month, date) with a suffix A for M20 or B for M21. For '69 it would be P9xxx, for '70 it would be P0xxx, etc.
I believe the A-B suffix identifying the M20 and M21 started after the '68.
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Old Apr 9, 2010 | 09:03 PM
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Originally Posted by DZRick
I believe the A-B suffix identifying the M20 and M21 started after the '68.
Guess so. According to the NCRS Corvette Specifications Guide, the suffixes were added effective October 21, 1968. I neglected to read the fine print at the bottom of the page. Happens when your old eyes get tired and you've had one too many already on a Friday night.
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Old Apr 9, 2010 | 11:01 PM
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Originally Posted by Clams Canino
Thanks! Any idea what would cause the driveshaft slip-yoke to look like crap on its outer surface where it goes into the tranny?

-W

age and rust.. it will prevent a good seal and you will be complaining of puddles on the floor, get you a new one, they are 85-135$$ or so depending on your spline count..

you don't really need a seal puller just use a hammer and a punch , since it is going in the trash anyway when you put a new one in its OK to destroy the seal..
here's my old and new one.. guess which one leaked?.. it needs to be a mirror finish or it will leak....


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Old Apr 10, 2010 | 08:43 AM
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If I might ask, where's the $85 to $135 deal please??

Zip has them for $130 and $160 for the 2 types. (with mine being the cheaper one)

-W
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Old Apr 10, 2010 | 12:45 PM
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This might help
http://corvette-world.com/corvette_1...on%20Codes.php
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Old Apr 10, 2010 | 05:06 PM
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Originally Posted by Clams Canino
If I might ask, where's the $85 to $135 deal please??
I have a brand new 27 spline repop you or anyone else can have for $75 delivered
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Old Apr 10, 2010 | 10:05 PM
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Originally Posted by Clams Canino

3. What about the bushing right behind it?
Yes but its a little tricky.
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Old Apr 10, 2010 | 10:18 PM
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Originally Posted by Clams Canino
Thanks! Any idea what would cause the driveshaft slip-yoke to look like crap on its outer surface where it goes into the tranny?

-W
The original yokes were made a little short IMO which allowed a little wobble,the newer after market yokes are longer and slide on to the output shaft further and have better support and don't wear the rear bushing out.
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Old Apr 10, 2010 | 11:45 PM
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Originally Posted by redvetracr
I have a brand new 27 spline repop you or anyone else can have for $75 delivered
OK.. to clarify. Mine has 26 splines by count - but there is a large space where there's a "missing spline" - I presume to allow it to go on only one way?

The one in Joewill's pic is not the one I have - I have the other one that's a little smaller on the yoke and takes a u-joint.

But yes... I'll go for the deal if it's the right one for 68-70.
And what means "repop"??

-W

As I recall... you and I did a pumpkin deal a while back - yes?

Last edited by Clams Canino; Apr 10, 2010 at 11:49 PM.
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Old Apr 11, 2010 | 12:30 AM
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Originally Posted by Clams Canino
OK.. to clarify. Mine has 26 splines by count - but there is a large space where there's a "missing spline" - I presume to allow it to go on only one way?

The one in Joewill's pic is not the one I have - I have the other one that's a little smaller on the yoke and takes a u-joint.

But yes... I'll go for the deal if it's the right one for 68-70.
And what means "repop"??

-W

As I recall... you and I did a pumpkin deal a while back - yes?

"repop" is short for reproduction, yes we did a pumpkin deal a while back. it has some rust protection on it but it`s brand new. $75 delivered.


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Old Apr 11, 2010 | 09:09 AM
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Originally Posted by redvetracr
"repop" is short for reproduction, yes we did a pumpkin deal a while back. it has some rust protection on it but it`s brand new. $75 delivered.
OK cool! Please PM me your Paypal email addy.

For extra credit - you don't have an a SS e-brake upper spring do you?

-W (broke 1 spring)
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Old Apr 13, 2010 | 05:04 AM
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Hi Guys
Would i be right in saying P1K2TA is a 71 M20 gearbox thats in my 68?
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