Transmission Leak MN6
Thread Starter
Instructor
Joined: Jan 2004
Posts: 152
Likes: 2
From: Pine Brook NJ
Transmission Leak MN6
I have a '00 FRC w/ 7K miles that just developed a transmission leak (found a small stain of red trans fluid in the garage). It is where the trans cases are bolted together towards the back of the trans just in front of where the trans is bolted to the diff. Did a search but can't find anyone with exact similar problem. It is not coming from the top of the trans so it is not the vent tube. Looks like the trans cases have silicone sealent between the two halves which is where the leak is - does any know if there is an O ring in there as well? (I have the 3 volume shop manual, but of course it only tells you how to remove and install the trans, not how to disassemble/assemble the cases). I can put a bead of silicone on the outside and retorque the bolts but I suspect it is wishful thinking that this will work. Has anyone else experienced this. The idea of dropping the trans just to reapply $.05 worth of silicone has got me more than a little pissed off. Any help/thoughts on this would be appreciated - thanks.
Le Mans Master
Joined: Dec 2003
Posts: 5,561
Likes: 448
From: Atlanta metro Ga.
Originally Posted by ZX-11
I have a '00 FRC w/ 7K miles that just developed a transmission leak (found a small stain of red trans fluid in the garage). It is where the trans cases are bolted together towards the back of the trans just in front of where the trans is bolted to the diff. Did a search but can't find anyone with exact similar problem. It is not coming from the top of the trans so it is not the vent tube. Looks like the trans cases have silicone sealent between the two halves which is where the leak is - does any know if there is an O ring in there as well? (I have the 3 volume shop manual, but of course it only tells you how to remove and install the trans, not how to disassemble/assemble the cases). I can put a bead of silicone on the outside and retorque the bolts but I suspect it is wishful thinking that this will work. Has anyone else experienced this. The idea of dropping the trans just to reapply $.05 worth of silicone has got me more than a little pissed off. Any help/thoughts on this would be appreciated - thanks.
Yes, there indeed is an O-ring (it sits on the end of the transmission, it's around 5 inches in diameter), but obviously you will have to separate the diff from the trans to get at it. In addition, no sealant applied on my set, just the o-ring.
And now the bad (or is it worse) news; that o-ring doesn't seal the transmission end, it seals the diff end (keeps the diff fluid from coming out). So even if you seal the case halves, you still have a problem because your trans fluid is leaking into the diff gear oil via the transmission output shaft seal. I suppose eventually you could blow up the trans (from lack of fluid) and the diff (via the gear oil being diluted w/ trans fluid). Sorry.
Drifting
Joined: Jul 2003
Posts: 1,647
Likes: 2
From: Peoples Republik of Kalifornia Ka
My 00 FRC with 8500 miles just went through the SAME problem. It turned out to be the axle seals. My after market warranty took care of the bill: $1400 worth. Its ashame but what else can ya do. IMO it is a must to purchase an after market warranty. Good luck 
Racer
Joined: Aug 1999
Posts: 466
Likes: 71
From: West Chester PA
ZX-11: I have the exact same problem on my ’98 MN6. This is not from the axle seals and not from the o-ring between the end of the transmission and the differential, as others in this thread suggest. It leaks where the end cap of the transmission bolts to the main case of the transmission. It just started a few weeks ago and is leaking a lot of fluid (3-4" puddle). It looks like there is just silicone used to seal the case. I’m not sure I trust any of the dealers to do this without messing up something else. I am still debating doing this myself but as you said it seems like a real waste to have to pull the transmission just to replace the silicone. If you find out anything more please let me know since I think we have the exact same problem. I will do the same if I learn anything else.
Regards, Ed
Regards, Ed
Le Mans Master
Joined: Dec 2003
Posts: 5,561
Likes: 448
From: Atlanta metro Ga.
Originally Posted by 98IndyPacer
It leaks where the end cap of the transmission bolts to the main case of the transmission.
Last edited by Dan_the_C5_Man; Aug 10, 2004 at 12:28 AM.
Drifting
Joined: Jul 2002
Posts: 1,262
Likes: 7
From: Kissimmee, FL
Here is something to consider - Red Line Fluids. Change both the trans and Diff fluids with the correct Red Line fluids. Red Line (in my opinion) causes just a bit of seal swelling - not enough to hurt anything but enough to fix some of these leaks. It won't cost you much to try it and it is better than the alternatives if it works. It did for me and it also helps improve the shifting. Good Luck!
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Drifting
Joined: May 2004
Posts: 1,917
Likes: 18
From: Tulsa OK
From the title of the post, I assume this thread refers to the manual tranny. I have an auto tranny and noticed drips on the garage floor right in the center rear of the car. It is not redish tranny fluid though; it is black like engine oil. I had it checked yesterday and was told it looked like it is coming from the pan area, possibly a gasket or seal needs replacing. I was told to have the pan dropped and the filter replaced. Does this sound reasonable or could it be something much more severe (and expensive 
)?
)?
Thread Starter
Instructor
Joined: Jan 2004
Posts: 152
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From: Pine Brook NJ
Thanks for the replies guys. Ed, sorry to hear that you are having the same problem but it helps to know that I am probably right about it being a problem with the mating of the case halves. I will try the redline, a bead of silicone and retorque the bolts. I can't believe that they designed a fluid holding case that is split vertically and they only have a bead of silicone to prevent leaks. Motorcycle case halves used to be like this until they figured out 30 years ago that this is a recipe for disaster in terms of leaks and swithched to cases that split horizontally.
Ed, let me know what you decide to do. Any other input would be appreciated.
Jim
Ed, let me know what you decide to do. Any other input would be appreciated.
Jim
Thread Starter
Instructor
Joined: Jan 2004
Posts: 152
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From: Pine Brook NJ
Ed - did you ever hear back from Crashed? I really don't have the time or desire to drop the trans. I see Cartek has a good deal on 3.90's - maybe I will spring for this and while they have the trans out they should be able to unbolt the trans cases and re-apply silicone for little extra money.
Let me know if you hear anything - would like to fix this soon.
Let me know if you hear anything - would like to fix this soon.
Racer
Joined: Aug 1999
Posts: 466
Likes: 71
From: West Chester PA
ZX: No response yet from Rodney. I sent him another email note. He may be really busy or even on vacation. I'll let you know if get a response.
Ed
Ed
Last edited by 98IndyPacer; Aug 14, 2004 at 06:08 PM.
Thread Starter
Instructor
Joined: Jan 2004
Posts: 152
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From: Pine Brook NJ
The car has been sitting for a few days with no drips. Will brake clean the **** out of the area and put a bead of silicone on it this afternoon. Hoping that since it hasn't dripped, the silicone will be able to set properly. Will also check to see if any of the bolts are loose. Will take it for a spin tomorrow and see what happens. I will let you know.
Former Vendor
Joined: Apr 2001
Posts: 10,976
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From: FL
St. Jude Donor '13
It is common for the silicone sealer on the rear trans reverse gear housing to deteriate and leak.The good news is that you do not have to remove the trans to reseal it,just the rear diff 
It is also possible for trans fluid to leak past the output shaft seal.This is a double seal that has dead air space between them.There is a bleed hole between the 2 seals that prevents fluid from leaking into the rear diff,or vice versa on the M6 should one of those seals leak Look for fluid coming out the bleed hole on the bottom of the trans where the trans and diff meet.You will also want to replace these 2 seals when the reverse housing is resealed,along with the big o-ring
It is also possible for trans fluid to leak past the output shaft seal.This is a double seal that has dead air space between them.There is a bleed hole between the 2 seals that prevents fluid from leaking into the rear diff,or vice versa on the M6 should one of those seals leak
Look for fluid coming out the bleed hole on the bottom of the trans where the trans and diff meet.You will also want to replace these 2 seals when the reverse housing is resealed,along with the big o-ring
Last edited by C-5 TECH; Aug 14, 2004 at 04:07 PM.
Racer
Joined: Aug 1999
Posts: 466
Likes: 71
From: West Chester PA
Ken: Thanks. I assume that I still have to drop the rear end out. I found this procedure http://www.corvettefever.com/howto/18978/index.html and then Mike's procedure to tilt the trans/diff http://mikemercury.home.att.net/342.htm
Is this the way to do it?
Thanks for your help!!!
Regards, Ed
Is this the way to do it?
Thanks for your help!!!
Regards, Ed
Former Vendor
Joined: Apr 2001
Posts: 10,976
Likes: 21
From: FL
St. Jude Donor '13
Originally Posted by 98IndyPacer
Ken: Thanks. I assume that I still have to drop the rear end out. I found this procedure http://www.corvettefever.com/howto/18978/index.html and then Mike's procedure to tilt the trans/diff http://mikemercury.home.att.net/342.htm
Is this the way to do it?
Thanks for your help!!!
Regards, Ed
Is this the way to do it?
Thanks for your help!!!
Regards, Ed
Thread Starter
Instructor
Joined: Jan 2004
Posts: 152
Likes: 2
From: Pine Brook NJ
Put a bead of high temp red permatex on it early this afternoon. 8 hours later it looks good - no sign of ATF. Checked the fluid level when I was under there (wanted to make sure I wasn't low) and it was a little high as a good stream of trans fluid came out. If I had to guess, maybe an eigth of a quart came out.
Tomorrow will be the test when I take it out for a ride - keeping my fingers crossed.
Good find on the write-up on the diff removal. Not sure if I am up for doing this on jack stands but I will keep it in mind if my quick fix does not work.
Tomorrow will be the test when I take it out for a ride - keeping my fingers crossed.
Good find on the write-up on the diff removal. Not sure if I am up for doing this on jack stands but I will keep it in mind if my quick fix does not work.
