gnb

I recently purchased a 2002 Z06- no leaks apparent anywhere.

Last week-end I drained and refilled the manual tranny with Mobil 1 ATF.

A week later while the vehicles was up on a lift - the tech and I noticed a film of atf fluid ( the red stuff) coating the bottom of what i guess is the bell housing ( not the rear of the tranny where the case is fitted together. No drips- not one- just a thin film on the bottom of housiing.

Wiped it clean thinking is may have been left over mess from my filling the tranny and overflow. Drove another 30 miles - and had the car up again for some maintenance I it appeared dry at first glance . The with my rding glasses and a flashlight I could see some moisture within the joint area of the mating surface of the 2 parts near the bottom weephole. Hmmmm.....I more carefully cleaned it up with a rag and Simple Greene degreaser. So no I will drive a week and se..

By the way - not a drop (or droplet) at all. No drops on the garage floor or on the bottom of tranny.

I hope this was just residual from my fill job.

Any thoughts ? Should I switch back to regular atf? Or if the Mobil 1 loosened the stuff- is it too late for regular atf to restore.

By the way- the Z06 is an 2002 model- but the mileage is low at 14,000.

Thanks

H/C/I Stang

iTrader: (11)

Leaky slave cylinder?

gnb

Nope - it is transmission fluid (red).

H/C/I Stang

iTrader: (11)

All the bolts tight on the tailshaft?

Use any goop/sealant on the fill and drain plugs?

Front pinion seal in good shape?

gnb

Thanks-

I did not use any goop or sealant on the thread of the fill/drain plugs. But i looked thre carefully and it appears dry near the plugs.

Can I use high temp teflon tape?

I pr0bably am not doing a good job describing where I noticed the seepage- it's at the bottom (around weephole) of where tranny bolts up to the "belllhousing" on the Corvette. Its the lowest point of the tranny- not the rear that bolts to the diffrential.

Again - I am hoping that since it's not even a drip, that it may be residual from my less than neat drain and refill job last wek end.

thesource

iTrader: (60)

Did you over fill it ?

H/C/I Stang

iTrader: (11)

If you were going to put some goop on there I would use just some run of the mill gasket maker like Hondabond.

I was refering to the pinion seal that the D/S slips into. It does not appear to have dripped down torwards the front of the transmission?

It could be just a little left over. But, if there was some again after you cleaned it up, there may be something more to it than that. Spray it with some brake cleaner and get EVERYTHING you can see off of the transmission. Then, go for another drive and see if it comes back.

gnb

Thanks Again !

Not certain where the pinion seal that the D/S ( What is that?) slip into is-

I will follow your recommendation clean off with Brake Cleaner and compressed air.

I am not a big sealr person - but if there is a leak seeping between the bellhousing gasket and tranny would an application of automotive clear RTV around the seam be a solution? I would have to spend $1400 in lablor to have the tranny pulled to replace a gasket if there is an effective "band aid" fix". The sepage, if that is what it even is, is ever slight not producing drips.

Aslo I have a UV light- suppose i could put some dye leak detector in the tranny and see if thre is a real seepage?

Say there is a slight seepage- is this a critical issue? Or can I just watch and add if when necessary more fluid. OTH- Should I just go by to dyno ATF and dump my recently installed Mobil 1 Syn ATF?

H/C/I Stang

iTrader: (11)

The pinion seal is the seal that covers the output shaft and the yoke that the driveshaft is mated to. It may be leaking out of there and down torwards the low part of the trans. D/S = Driveshaft.

I wouldn't simply just cap the leak off. I would spend my time trying to figure out where it is coming from and fix it at that point. There isn't a gasket between the bellhousing and engine to my knowledge. There isnt anything inside the bellhousing that would leak other than a slave and it is not that. Your leak is coming from somewhere else.

If you cannot immediately find the leak, I don't see why putting some dye in your fluid would hurt anything. Maybe the cardboard blocker rings inside the transmission if anything. But, I'm not sure whether or not the MN12 has the cardboard pieces in it.

It could be a critical issue. Not likely, but possible. The Mobil 1 fluid is what I run in my transmission as well and I would not just dump it out because there "could" be a leak now. The fluid has nothing to do with this new found problem.

gnb

Thanks for your patience in explaining !

The Corvette C5's bellhousing ( i think) is connected to the tranny - but this is rear of the engine separated by a torque tube.

I could not find dye compatable with at fluid- they only seem to make for engine oil and coolant.

Anyhow- I will vigilantly watch and hope for the best. I do know that fluid finds the lowest point. It certaintly is possible still that it is residual from the messy drain and refill i did last week.

I needto install the CAGS defeat switch - while under the car I will clean thoroughly with brake cleaner as you suggested and follow up with a good compressed air spraying.

I am like you- I dont see Mobil ! being the issue. I have been running Mobil 1 syn fluids in all my vehicles sice 1988 without issue.

Thanks- I will keep you posted.

gnb

This afternoon I put my Z06 up to install the CAGS defeat gizmo.

While under the car- I saw there was a slight wetness of ATF around the weephole between the bllhousing ( i think that wat it is) and the front of the 6 speed manual gearbox.

Since I did a drain and refill last week-end - I removed the fill plug and and allowed some of the excess ATF to drain out. This I am thinking maght possibly have contributed to the weepage?

I think I understand your point now about a seal around the "pinion" shaft possibly being the source of the leak.

Question - the car is a 2002 Z06 with only 14K miles. Is it conceivable that the seals shrunk ( or something) and that they may re-gain they pliability and begin sealing better?

As it is - the leak is more of a slight weepage. No drops - on car or garage floor.

Any benefit under this theory of going back to dyno based aft?

Thanks

thesource

iTrader: (60)

If it was over filled , then it was more than likely coming out of the vent tube at the top of the transmission .

gnb

Thanks - that would be nice, however I only saw weepage at the bottom. I know leaks can be strange sometimes to isolate.

BTW- I think I had my terminology wrong. The weepage is at the junction of what I think is called the torque tube and thefront of the manual gearbox.( so not the bellhousing - which is kinda what the thing looks like).

Obviously the seepage is very little - for there to be enough excess ATF to still dribble out of the fill plug hole for 5 minutes. This after a week of driving and about - say 250 miles.

Must be a huge job to fix- the tech where I had the car up said it would take all day and cost about $1,200 to replace $50 in parts -OUCH!

I think I can live with a minor weepage as long as my garage floor is not showing a puddle.

Is any weepage at all normal ? I know the differentials have issues on the c5 corvettes. But Not sure about the issue I have described related to the front of the transmission.

thesource

iTrader: (60)

If you are seeing ATF running out of the front of the area that bolts to the torque tube its either the front seal or the shift rail seal . If its the front seal , you could have bigger issues like a bad inputshaft tip and bad pilot bearing . If its the shift selector seal , it will still require the unit to be pulled from the car to be repaired . I would mae certain thats what it is before pulling the unit . The vent tube is at the top and the fluid will run down the case and in most cases toward the rear of the car from the wind under the car as its driving down the road .

gnb

Thanks so much !

Well- Like I said, after a week of driving(over 250 miles) it still had some overfill which I let out yesterday. The overfill dribbled out for at least 5 minutes.

As far as my "leak" - I am not talking a drop even- merely a slight very thin film of atf. Since I still had overfill from the drain / refill job I did 7 days ago - and in between drove the car 250 miles, it's clear the ATF is not spewing out under pressure. So- absolutely no way I am goin to do anything unless it gets a lot worse ( as in leaving a puddle on my garage floor- or even several drops).

I will continue to check the fluid level weekly for a while. Based on what I see I would be surprised if in even 6 months to a year I have to top the fluid off.

Actually - the mileage on this vehicle is so low for a 2002 I am thinking if it even is a seal ( as opposed to fill drain off) it may improve its sealing qualities with driving. Auto transmissions equipped cars that aren't driven much are known for this - and the seals normally improve with regular driving.

Thank You