Leaking M-20
Thread Starter
Le Mans Master
Joined: Feb 2006
Posts: 5,073
Likes: 414
From: Maine
Leaking M-20
Hi,
Never had a problem until I put in new back up light bracket.
As I am restoring my 66 roadster, L79, I thought that after almost 40 years, (put in a Hurst in 1970 ) and broke the back up light switch, it was time to put in new switch.
Had to take out two bolts on side cover to attach switch. (30 lbs torque) Has been leaking since. Just a little, but after fixing my engine (Oil Pressure Saga thread) , oil on the ground makes my crazy.
Any suggestions on stopping it. Can I change the gasket without taking out tranny? Can I put something on the bolts?
Can over filling tranny cause leaking ?
Jack
Never had a problem until I put in new back up light bracket.
As I am restoring my 66 roadster, L79, I thought that after almost 40 years, (put in a Hurst in 1970 ) and broke the back up light switch, it was time to put in new switch.
Had to take out two bolts on side cover to attach switch. (30 lbs torque) Has been leaking since. Just a little, but after fixing my engine (Oil Pressure Saga thread) , oil on the ground makes my crazy.
Any suggestions on stopping it. Can I change the gasket without taking out tranny? Can I put something on the bolts?
Can over filling tranny cause leaking ?
Jack
Last edited by Jackfit; Aug 25, 2009 at 06:39 AM. Reason: material
Drifting
Joined: Jul 2005
Posts: 1,977
Likes: 195
From: Putnam Valley, New York. Amateur Radio Operator K2NS
Trans leak
Pull those 2 bolts out again, clean the 2 bolts, and then reinstall them with a coating of permatex #2 sealer or some equivalent. I guess that you could also use silicone gasket maker (blue snot) if you couldn't find anything else. I don't think that removing those 2 bolts would have ruined the cover gasket, but if the leak continues, the side cover can be removed with the trans in the car. Are you sure of the torque ??? They're only 5/16" bolts--30 foot pounds sounds a little high--The chassis overhaul manual states 20 foot pounds--I hope you didn't strip the threads in the aluminum case.
RON
Last edited by rongold; Aug 24, 2009 at 11:51 PM.
Le Mans Master
Joined: Oct 2000
Posts: 6,209
Likes: 33
From: Texas-out west
did you put car in a "hearst" 
sorry couldn't resist...it is "hurst"
agree on the permatex #2, use some grey gasket maker if you remove cover, similar to what toyota uses on oil pans when not using a gasket, works great, autozone has it. good luck with the leak.
sorry couldn't resist...it is "hurst"agree on the permatex #2, use some grey gasket maker if you remove cover, similar to what toyota uses on oil pans when not using a gasket, works great, autozone has it. good luck with the leak.
Last edited by LT1driver; Aug 25, 2009 at 12:16 AM.
Thread Starter
Le Mans Master
Joined: Feb 2006
Posts: 5,073
Likes: 414
From: Maine
Right 20 lbs
Pull those 2 bolts out again, clean the 2 bolts, and then reinstall them with a coating of permatex #2 sealer or some equivalent. I guess that you could also use silicone gasket maker (blue snot) if you couldn't find anything else. I don't think that removing those 2 bolts would have ruined the cover gasket, but if the leak continues, the side cover can be removed with the trans in the car. Are you sure of the torque ??? They're only 5/16" bolts--30 foot pounds sounds a little high--The chassis overhaul manual states 20 foot pounds--I hope you didn't strip the threads in the aluminum case.
RON
Jack
Thread Starter
Le Mans Master
Joined: Feb 2006
Posts: 5,073
Likes: 414
From: Maine
It might be mine
Thanks I will try the easy fix first.
Jack
Thread Starter
Le Mans Master
Joined: Feb 2006
Posts: 5,073
Likes: 414
From: Maine
Bolts not leaking seems to be lip seal on shifter shaft
Pull those 2 bolts out again, clean the 2 bolts, and then reinstall them with a coating of permatex #2 sealer or some equivalent. I guess that you could also use silicone gasket maker (blue snot) if you couldn't find anything else. I don't think that removing those 2 bolts would have ruined the cover gasket, but if the leak continues, the side cover can be removed with the trans in the car. Are you sure of the torque ??? They're only 5/16" bolts--30 foot pounds sounds a little high--The chassis overhaul manual states 20 foot pounds--I hope you didn't strip the threads in the aluminum case.
RON
Cleaned bolts and put Permatex sealer on all of them.. 20 lbs torque. Still leaks. Found leak. It seems to be leaking from 1 and 2 gear shifter shaft. My chassis manual shows a lip seal in the side cover. Can that seal be replaced without removing side cover? It seems pressed into side cover opening where shaft comes through cover.
Jack
Burning Brakes
Joined: Aug 2001
Posts: 1,104
Likes: 1
From: Frederick Md
Hi Ron,
Cleaned bolts and put Permatex sealer on all of them.. 20 lbs torque. Still leaks. Found leak. It seems to be leaking from 1 and 2 gear shifter shaft. My chassis manual shows a lip seal in the side cover. Can that seal be replaced without removing side cover? It seems pressed into side cover opening where shaft comes through cover.
Jack
Cleaned bolts and put Permatex sealer on all of them.. 20 lbs torque. Still leaks. Found leak. It seems to be leaking from 1 and 2 gear shifter shaft. My chassis manual shows a lip seal in the side cover. Can that seal be replaced without removing side cover? It seems pressed into side cover opening where shaft comes through cover.
Jack
Try putting the side cover on, the forks stick out about 5 plus inches, is there enough room to do this???? I don't think so.
Also if you attempt to do this, shift the trans into second, makes it a lot easier.
Last edited by muncieman; Sep 4, 2009 at 12:04 PM.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Burning Brakes
Joined: Aug 2001
Posts: 1,104
Likes: 1
From: Frederick Md
Let's talk about this.
You will need to rotate the trans so the side cover is facing down. Remove the side cover bolts and catch all the gear oil as it come out all at once, unless you have a drain plug.
Now you can remove the shift shafts, remove the old seals and replace them. If you don't have them, your local parts store will look at you like your nuts when you ask for them.
I have them, $1 each. Now you need to clean up the case for the side cover gasket. I also have those.
There is one thing that has not been mentioned, the side covers have been known to wear and get sloppy on the fit of the shift shafts, replacing the seal may not fix the problem.
Now, tack the gasket to the side cover, shift the trans into second gear, put the cover on. Spin her back into position and button it up.
Don't forget to get some GL-4 gear oil or the MT-90 syn by RED LINE.
.
Thread Starter
Le Mans Master
Joined: Feb 2006
Posts: 5,073
Likes: 414
From: Maine
Thank you for your offer
If you try this in the car, the shifter will need to come off, bolts out the trans to bell housing, bolts removed from the trans mount.
You will need to rotate the trans so the side cover is facing down. Remove the side cover bolts and catch all the gear oil as it come out all at once, unless you have a drain plug.
Now you can remove the shift shafts, remove the old seals and replace them. If you don't have them, your local parts store will look at you like your nuts when you ask for them.
I have them, $1 each. Now you need to clean up the case for the side cover gasket. I also have those.
There is one thing that has not been mentioned, the side covers have been known to wear and get sloppy on the fit of the shift shafts, replacing the seal may not fix the problem.
Now, tack the gasket to the side cover, shift the trans into second gear, put the cover on. Spin her back into position and button it up.
Don't forget to get some GL-4 gear oil or the MT-90 syn by RED LINE.
.
You will need to rotate the trans so the side cover is facing down. Remove the side cover bolts and catch all the gear oil as it come out all at once, unless you have a drain plug.
Now you can remove the shift shafts, remove the old seals and replace them. If you don't have them, your local parts store will look at you like your nuts when you ask for them.
I have them, $1 each. Now you need to clean up the case for the side cover gasket. I also have those.
There is one thing that has not been mentioned, the side covers have been known to wear and get sloppy on the fit of the shift shafts, replacing the seal may not fix the problem.
Now, tack the gasket to the side cover, shift the trans into second gear, put the cover on. Spin her back into position and button it up.
Don't forget to get some GL-4 gear oil or the MT-90 syn by RED LINE.
.
I was at Carl Hinkson's camp today, took him for a first ride in car with his engine rebuild, and mentioned the leak. He said that there is a possibility that my transmission may vented and that it may be blocked.
When I opened the drain plug when this leak first appeared , the oil squirted out as if it were under pressure. Does my M-20 have a vent? and if it were blocked could the oil find the least resistance in the shaft seal.
Thanks
Jack
Burning Brakes
Joined: Aug 2001
Posts: 1,104
Likes: 1
From: Frederick Md
I will contact you when I get ready to take apart the car again. I am going to live with it while the weather is great here in Maine.
I was at Carl Hinkson's camp today, took him for a first ride in car with his engine rebuild, and mentioned the leak. He said that there is a possibility that my transmission may vented and that it may be blocked.
When I opened the drain plug when this leak first appeared , the oil squirted out as if it were under pressure. Does my M-20 have a vent? and if it were blocked could the oil find the least resistance in the shaft seal.
Thanks
Jack
I was at Carl Hinkson's camp today, took him for a first ride in car with his engine rebuild, and mentioned the leak. He said that there is a possibility that my transmission may vented and that it may be blocked.
When I opened the drain plug when this leak first appeared , the oil squirted out as if it were under pressure. Does my M-20 have a vent? and if it were blocked could the oil find the least resistance in the shaft seal.
Thanks
Jack
Drifting
Joined: Jul 2004
Posts: 1,554
Likes: 168
From: Wi
If you try this in the car, the shifter will need to come off, bolts out the trans to bell housing, bolts removed from the trans mount.
You will need to rotate the trans so the side cover is facing down. Remove the side cover bolts and catch all the gear oil as it come out all at once, unless you have a drain plug.
Now you can remove the shift shafts, remove the old seals and replace them. If you don't have them, your local parts store will look at you like your nuts when you ask for them.
I have them, $1 each. Now you need to clean up the case for the side cover gasket. I also have those.
There is one thing that has not been mentioned, the side covers have been known to wear and get sloppy on the fit of the shift shafts, replacing the seal may not fix the problem.
Now, tack the gasket to the side cover, shift the trans into second gear, put the cover on. Spin her back into position and button it up.
Don't forget to get some GL-4 gear oil or the MT-90 syn by RED LINE.
.
You will need to rotate the trans so the side cover is facing down. Remove the side cover bolts and catch all the gear oil as it come out all at once, unless you have a drain plug.
Now you can remove the shift shafts, remove the old seals and replace them. If you don't have them, your local parts store will look at you like your nuts when you ask for them.
I have them, $1 each. Now you need to clean up the case for the side cover gasket. I also have those.
There is one thing that has not been mentioned, the side covers have been known to wear and get sloppy on the fit of the shift shafts, replacing the seal may not fix the problem.
Now, tack the gasket to the side cover, shift the trans into second gear, put the cover on. Spin her back into position and button it up.
Don't forget to get some GL-4 gear oil or the MT-90 syn by RED LINE.
.
Last edited by skids; Sep 4, 2009 at 10:09 PM.
Thread Starter
Le Mans Master
Joined: Feb 2006
Posts: 5,073
Likes: 414
From: Maine
Sounds like I have a leaky cover
I will ask for more detailed help, when it is 3 am and I am on my back under the car, with oil dripping on my face.
Thanks everyone for the advice.
Jack
Last edited by Jackfit; Sep 4, 2009 at 11:01 PM. Reason: additional material
Instructor
Joined: Apr 2008
Posts: 228
Likes: 8
From: northern Virginia
Jackfit, what part of Maine are you in? I lived in Brunswick for 4 and then later 2 years. Made it to the Owl's Head corvette show in 2007.
Didnt have my '66 then, was just a spectator.
Perfect time of year to be cruisin' in Maine!!
Didnt have my '66 then, was just a spectator.
Perfect time of year to be cruisin' in Maine!!
Thread Starter
Le Mans Master
Joined: Feb 2006
Posts: 5,073
Likes: 414
From: Maine
Cape Elizabeth
What a pain to have a leak after almost all the hard work on the engine and restoration is done,
Jack
Burning Brakes
Joined: Aug 2001
Posts: 1,104
Likes: 1
From: Frederick Md
That would be a Auto-Gear roller bearing side cover which uses a newer and stonger shift shaft, stock shift shaft is to small for the new side cover.
Drifting
Joined: Jul 2004
Posts: 1,554
Likes: 168
From: Wi
Thread Starter
Le Mans Master
Joined: Feb 2006
Posts: 5,073
Likes: 414
From: Maine
Lets talk about this
If you try this in the car, the shifter will need to come off, bolts out the trans to bell housing, bolts removed from the trans mount.
You will need to rotate the trans so the side cover is facing down. Remove the side cover bolts and catch all the gear oil as it come out all at once, unless you have a drain plug.
Now you can remove the shift shafts, remove the old seals and replace them. If you don't have them, your local parts store will look at you like your nuts when you ask for them.
I have them, $1 each. Now you need to clean up the case for the side cover gasket. I also have those.
There is one thing that has not been mentioned, the side covers have been known to wear and get sloppy on the fit of the shift shafts, replacing the seal may not fix the problem.
Now, tack the gasket to the side cover, shift the trans into second gear, put the cover on. Spin her back into position and button it up.
Don't forget to get some GL-4 gear oil or the MT-90 syn by RED LINE.
.
You will need to rotate the trans so the side cover is facing down. Remove the side cover bolts and catch all the gear oil as it come out all at once, unless you have a drain plug.
Now you can remove the shift shafts, remove the old seals and replace them. If you don't have them, your local parts store will look at you like your nuts when you ask for them.
I have them, $1 each. Now you need to clean up the case for the side cover gasket. I also have those.
There is one thing that has not been mentioned, the side covers have been known to wear and get sloppy on the fit of the shift shafts, replacing the seal may not fix the problem.
Now, tack the gasket to the side cover, shift the trans into second gear, put the cover on. Spin her back into position and button it up.
Don't forget to get some GL-4 gear oil or the MT-90 syn by RED LINE.
.
unbolt cover. Does cover come off with shift shafts ? Let me know what happens once I take cove off. I just replace seals this time I think, rather than change cover, Unless cover has real wear.
Any help on what to do when I have cover off will help. I will ask you for seal etc, later
Thanks
Jack
Burning Brakes
Joined: Aug 2001
Posts: 1,104
Likes: 1
From: Frederick Md
Thanks for advice. Now let me get this straight, Drain tranny, Unbolt linkage, No problem turning tranny. (yea sure) . Once that is done,
unbolt cover. Does cover come off with shift shafts ? Let me know what happens once I take cove off. I just replace seals this time I think, rather than change cover, Unless cover has real wear.
Any help on what to do when I have cover off will help. I will ask you for seal etc, later
Thanks
Jack
unbolt cover. Does cover come off with shift shafts ? Let me know what happens once I take cove off. I just replace seals this time I think, rather than change cover, Unless cover has real wear.
Any help on what to do when I have cover off will help. I will ask you for seal etc, later
Thanks
Jack
The side cover will come off with the shift shafts and forks along with all the oil!!!
Drifting
Joined: Jul 2005
Posts: 1,977
Likes: 195
From: Putnam Valley, New York. Amateur Radio Operator K2NS
Trans Side Cover
Put a floor jack and a 2X4 under the engine oil pan to slightly lift everything up while you spin the trans. Just don't let the trans slip backwards. You probably don't have to spin it more than 45 degrees to get enough room to pull the cover. Make sure the trans is in 2nd gear to allow the 1-2 fork to be removed with the cover. After you get the cover off, take a good look at how the lockout mechanism works and pull the 2 forks. Then remove the lockout spring. Swing the lockout levers out of the way, and you can then remove the 2 shifter shafts by just pulling them out. Remember which is which--I seem to remember that they are different and need to go back in the same location. With the shafts out, just take a screwdriver and pry the seals out. Be careful not to scratch the bores. Install the 2 new seals and then the shafts. Lube the seals with gear oil before you insert the 2 shafts. Reinstall the lockout spring and then the 2 forks while holding the lockout levers up. Make sure that the 1-2 shaft is in the second gear (forward) position. Clean the case and side cover surfaces and reinstall the cover along with a new gasket. Spin the trans upright and reinstall everything. Don't forget to refill the trans.
RON
P.S. I don't think you will be able to spin the trans while it is in gear unless you have the rear wheels off the ground. You will have to put it into 2nd after you spin it. Leave the 1-2 lever on to accomplish this, and remove it to pull the shaft out. After you have the cover back on, reinstall the 1-2 lever and put the trans in neutral to spin the trans vertical again. Hope I didn't confuse you.