csc67

I have a transmission fluid leak located at the bottom of my YR 2000 vette.

1) What options do I have to fix this issue?

2) Approx. cost?

3) Has anyone successfully repaired this without pulling the two parts apart (some kind of sealant placed in the actual transmission or a bead of sealant where they meet)?

bumble-z

After a few years that black sealant that was applied from the factory between the two units deterorates, thus causing it to leak from that particular area.

I would not waste the time of trying to cover up the problem from the outside.
The two sections would have to be taken apart & resealed to do the job properly.
There is also a seal that would need replaced that goes around the tranny shaft & a large O ring that snugs the diff & tranny.
I would live with it untill the time comes when you need to drop the rear cradle for one thing or the other.
Good luck.

Dope

You can clean off the underside of this connection really well (brake cleaner, etc) and then put a thin layer of high temp RTV on the bottom half of the assembly to help with the leak. I did this for a year or two until the next time I had to drop the rear subframe and separate the pieces. It did not leak a drop in that time.

Dope

SaberD

there is a trick where you can hook up a shop vac to the fill hole after the fluid is drained. then suck the sealant up into the leak after you clean it. still only a temp fix, but should work better than just applying it to the outside.

Eric D

Is there a chance that the trans is over serviced with fluid? Could it be from the vent on top of the trans?

jsbzoh6

My '00 is on ramps right now letting the RTV dry for this very same problem. I also have a leaky butt I need to fix, but the transmission fluid leak leaves me with a small puddle overnight so it needed some more immediate attention. I don't have the time or funds to replace the clutch and its downright silly to take everything out and NOT do that, so I'm trying the "band-aid" of just RTVing the outside. I'll let you know if it works or not, but it looks IDENTICAL to my leak, so my bet would be coming from where the two halves meet.

Z06supercharged

Mine has been leaking there for 4 years now. Its just a small drip that started when I changed to synthetic fluid and I have only needed to add 1/2 qt a year so I never bothered fixing it even though Ive had my driveline out a couple times doing a clutch and diff seals but I went back to non synthetic trans fluid with this last clutch I put in and leak has all but stopped now to a small drip every couple days. One of these days maybe ill fix it with a gasket but I really doubt it.
Its another stupid idea not wanting to use a actual gasket when they should have.

Dixiecrat

Funny this subject came up today, as today I had my 8 year old transmission fluid changed I have an 03 with 9000 miles on it yes 9 thousand not 90. I was looking under the car while on the rack and the tech showed me my trans was leaking. just a spot, not as bad as the picture posted. I ask him about it and hev said if it were his and not leaking any worse then that he wouldn t do anything yet. He told me to watch where I park it and if it was dripping oil then fix it. I do not have a drop in the garage. I explained to him that the car sat 5 years and only had 750 miles put on it. He said that was the reason. He said it is a common problem with the C5 and a big reason is not driving the car. when the car sits there is an 0-ring that doesn t get oil on it and it dries and leaks. I ask repair cost he said bout $600. I ask him if that would fix it forever and he said no garentee. By looking at your pictures thats a big leak and i d fix ASAP as a transmission AINT cheap.

Z06supercharged

The trans O ring that is prone to leaking as above mentioned is a different type of leak that is not the same leak from the 2 halves not sealing caused by no gasket being used by the factory. That fix is a little more involved for the 0 ring replacement..

Dixiecrat

OK, Im not a tech so how do I know hes not goin to just milk me out of $600. And how did he know it was an 0-ring as opposed to the two halfs as all he did was look at it with a light.

Dixiecrat

He called it a sepage not a leak.

Z06supercharged

The 2 shaft 0 rings and large case outer O ring are in back of trans tailshaft housing where it bolts to the diff. This is not the same place that is leaking that the OP of this thread posted a picture of. They are 2 different areas prone to leakage. The OP's picture above is where the trans tail housing mates to the main trans case. There is no gasket there and it leaks eventually on most cars. The case can sometimes be pulled apart just enough and rtv put in between halves to fix the leak. Some people get it sealed again without pulling halves completely apart but be careful as to not pull it too far apart unless its standing vertical on end. I knew a guy that was gonna just pull it slightly apart while still in cradle but dont know if he ever did that successfully or not.

Here is a link showing closeup pics where the tailshaft O rings are that your mechanic is talking about. There is usually a hole in bottom of most tailshaft housings that weep fluid when one of the O rings is leaking. It will either leak trans fluid or diff oil depending which O ring is leaking.http://forums.corvetteforum.com/c5-t...-rear-end.html

Here is a excellent link to rebuild pics and you can see exactly what goes where with O rings and case halves. The first pic shows you the case front half that uses no gasket to mate to the tailshaft housing, then the tail housing to the right with O rings shown.http://forums.corvetteforum.com/nort...-smoother.html

magneticred

I had a similar problem. Sorry to say that the transmission had to be removed to reseal the two halves (front/back) and it cost over $1000.

Z06supercharged

Book rates are very high to remove cradle and trans for the fix and why most people just let it leak or try and RTV the halves or like me just too lazy to fix it when its out in the garage when doing a clutch..

Dixiecrat

Thanks guys, I ll keep a close eye on the garage floor.

Ultimate ride

Just had the trans/diff leak fixed last year. It started leaking again this year and I had it fixed again. Now, a few weeks later, it is leaking again. All transmission fluid. It is going in again this month. What a PITA!

Dixiecrat

Sounds like a problem GM engineers just cant fix.

csc67

Great collection of thoughts and input

For the people that used the RTV along the seal, did you drain the fluid first?

Great idea to check the top vent - I actually cleaned the entire area and then checked the sides of the transmission to see if I had tranny fluid on the side - Sides were dry

I also checked the fluid level since a transmission replacement would be very expensive - I placed the car on four ramps on a fairly level surface and when I opened the fill bolt I had some fluid leak out

Keep the ideas / thoughts coming

lucky131969

What else are you looking/hoping for? You have four choices:

1) Live with the leak

2) Bandaid fix with a bead of RTV

3) Have the seal replaced at a trusted shop

4) Use an additive leak stop

RX-Ben

I cleaned up the area really well and put on RTV and it sealed it. As mentioned, this is likely caused by the o-ring that goes on the trans snout, which seats in the diff.
The RTV method is cheap and takes about an hour, 45min to clean/dry and then 15 to dab on the RTV. I did not drain the fluid before adding RTV.