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What I did this Winter -- or what my C3 did do me. . . (1/12)
 4/14/19 3:37pm
BillHanna
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Cana, VA - USA

Vette(s):
1975 Stingray


Joined: 7/3/2016
Posts: 161

My 75 coup has been jumping out of 2nd gear when decelerating since I got the car 3 years ago, so I pulled the engine/transmission last fall to fix it.

After disassembling the Borg Warner Super T-10, I could not see anything amiss so I installed new bearings and synchros and put it all back together again.

It still jumped out of 2nd gear, so I pulled the engine/transmission again and took the transmission to a transmission shop for them to go through it.  After puzzling over it for a week, he asked another shop to take a look at it and they finally realized that the sleeve under the 1/2 gear set was not pressed on all the way.

While the engine was out this time, I decided to replace the camshaft.  It was starting to wear and I wanted a bit more power (who doesn't!).  After getting it all back together again, I drove it about 10 miles and the camshaft destroyed itself.  I've build many engines over the years but never had an issue like this.

Since the engine was now full of metal from the camshaft and lifters, I took it to a machine shop to be tank cleaned and checked out.  I showed them the camshaft, and the first question asked was "Did you add zinc additive to the oil?"  Since 1980 this and other additives were removed from the oil because of the catalytic converters.  I did not know this and there were no instructions with the camshaft.

The machine shop found that the crankshaft needed to be turned and the cylinders needed to be bored.  So I put flat-top pistons in to gain a little compression (I get about 180 PSI and it should be about 10:1 compression ratio).  I also got a Comp Cams camshaft which came with about 10 pages of instructions on oil/additive to use and break-in procedure.

After putting the engine back in for the 3rd time and starting it, it made an awful racket.  It sounded like valve-train, but I could not pin it down.  So back came the engine again (this time I left the transmission in place, thinking it would save some time).  I took the heads to the machine shop and they found the valve springs were very weak.  So they replace these and used the new style valve seals.

Back in whet the engine for the 4th time, but we could not get it to line up with the 4-speed transmission in place, so we pulled the transmission and put the engine/transmission in together.

It now runs great, and sounds a lot more powerful -- which is what I was really looking for in the new camshaft.

So a simple rebuild of the transmission turned into a complete overhaul of the engine.  And guess what -- the transmission still jumps out of 2nd gear!





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Re: What I did this Winter -- or what my C3 did do me. . . (2/12)
 4/14/19 6:11pm
73shark
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Overland Park, KS - USA

Vette(s):
1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.


Joined: 7/9/2003
Posts: 550

I thought all camshaft manufacturers supplied a bottle of Break In Lube to pour over the lifters and bearings during installation. Sounds like you need to get a Muncie 4-speed and drop in it. ;)

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1973 L-82 4 spd

Re: What I did this Winter -- or what my C3 did do me. . . (3/12)
 4/14/19 7:47pm
BillHanna
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Cana, VA - USA

Vette(s):
1975 Stingray


Joined: 7/3/2016
Posts: 161

73shark said: I thought all camshaft manufacturers supplied a bottle of Break In Lube to pour over the lifters and bearings during installation. Sounds like you need to get a Muncie 4-speed and drop in it. ;)

I did use assembly lube but that was not adequate.
The Comp Cams camshaft instructions said that a bottle was included, but it was not.
I used a high-pressure graphite break-in assembly lube, along with break-in oil for the 2nd camshaft and that seemed to work fine.
I also will add zinc additive to the next oil changes just to be sure.

When I was a teanager I bought a Muncie 4-speed for $100.00 but they are a bit more now. . .


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Re: What I did this Winter -- or what my C3 did do me. . . (4/12)
 4/14/19 9:30pm
73shark
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Overland Park, KS - USA

Vette(s):
1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.


Joined: 7/9/2003
Posts: 550

I guess neither one of your cams were roller cams then. GM makes an additive called EOS which stands for Engine Oil Supplement. They recommend adding a couple of bottles for the initial oil fill and it has a high zinc content. I'm sure there are other aftermarket high zinc additives you can use also. Sounds like you've got it handled though.

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1973 L-82 4 spd

Re: What I did this Winter -- or what my C3 did do me. . . (5/12)
 4/15/19 12:23am
NorskyLifetime Member
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Twin Lakes, CO - USA

Vette(s):
SOLD - "The Toy" - 1970 Convertible
SOLD - "The Beast" - 1990 ZR-1 (#682)
"BLKBRRD" - 1978 Trans Am, 400ci/225hp, 4 spd, Black w/black interior, Hurst t-tops


Joined: 1/23/2002
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My, my - you have been a BUSY fellow...!!!  Shocked

SUPER frustrating to have gone through all that time, energy and $$$ to not have everything working perfectly.  Does the tranny shop have any other ideas on what could be wrong?  Hopefully they'll stand behind their work and make it right.


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Jim Olson 

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Re: What I did this Winter -- or what my C3 did do me. . . (6/12)
 4/15/19 1:08am
73shark
Standard Member
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Overland Park, KS - USA

Vette(s):
1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.


Joined: 7/9/2003
Posts: 550

I remember a co-worker with a 73 Coupe with a 4-speed that actually removed his transmission in his apartment's parking lot during the winter. So it can be done without removing the engine.

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1973 L-82 4 spd

Re: What I did this Winter -- or what my C3 did do me. . . (7/12)
 4/15/19 1:13pm
Adams' AppleLifetime Member
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Duncanville, TX - USA

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#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas


Joined: 11/8/2003
Posts: 19627

 Dang Bill......Ouch
Iffin you weren't so far away, I'd suggest sending the trans down to Texas...I can fix it for ya. Chances are there is simply too much end-play in it, and most places won't take the time to actually check stuff like that.



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Joel Adams
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Re: What I did this Winter -- or what my C3 did do me. . . (8/12)
 4/15/19 2:00pm
BillHanna
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Cana, VA - USA

Vette(s):
1975 Stingray


Joined: 7/3/2016
Posts: 161

73shark said: I remember a co-worker with a 73 Coupe with a 4-speed that actually removed his transmission in his apartment's parking lot during the winter. So it can be done without removing the engine.

I've heard of others taking the manual transmission out without the engine but it has to be a very tight job.  You would at least have to remove the exhaust pipes, which can be a bit of a job in itself.
I also have heard that some cut the cross member to make it removable, but that would also require removing the exhaust pipes -- not an easy job laying on your back under tight quarters.
After pulling the engine 4 times this winter, I can almost do it in my sleep. . .



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Re: What I did this Winter -- or what my C3 did do me. . . (9/12)
 4/15/19 2:03pm
BillHanna
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Cana, VA - USA

Vette(s):
1975 Stingray


Joined: 7/3/2016
Posts: 161

Adams' Apple said:
 Dang Bill......Ouch
Iffin you weren't so far away, I'd suggest sending the trans down to Texas...I can fix it for ya. Chances are there is simply too much end-play in it, and most places won't take the time to actually check stuff like that.


Appreciate the thought, but I'm done pulling it for a while.  It only comes out of gear when decelerating in 2nd, which I can avoid pretty easily.

The people in this forum have been lifesavers many times over with answers to issues that I have run into.  Thanks to all!  Hope to see many of you in Canada this summer.


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Re: What I did this Winter -- or what my C3 did do me. . . (10/12)
 4/16/19 3:22pm
BillHanna
Standard Member
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Cana, VA - USA

Vette(s):
1975 Stingray


Joined: 7/3/2016
Posts: 161

Norsky said: My, my - you have been a BUSY fellow...!!!  Shocked

SUPER frustrating to have gone through all that time, energy and $$$ to not have everything working perfectly.  Does the tranny shop have any other ideas on what could be wrong?  Hopefully they'll stand behind their work and make it right.

I stopped by the transmission shop today.  He said that if I pull it again, he would take another look at it -- but I'm done for now.  Time to drive it!




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