Cookwithvette

My car has been sitting, undisturbed, since November 1st. The bay is not heated. I had to check the milage for registration so I paid her a visit today. Just for the heck of it I checked underneath. A couple puddles under power steering components but I knew those were shot and a few from the transmission area.

My question is this.... with the extended cold weather, and dozen or so thaws would this be considered fairly normal. I'm not talking a huge amount, maybe two tablespoons (one ounce) of fluid.

page62

No, but once they start leaking...good luck stopping 'em! :lol:
Fluid is cheap; reseal jobs are not.

GrandSportC3

:iagree:

Corz

mine leaks like a siv... maybe i should've tightened that last bolt... :banghead: oh well

77Dream

I think those storage compartments in the back are designed to put tranny fluid in. ;)

redwingvette

I have been fighting mine for years. Change the pan gasket every spring and by fall it is leaking again. I have changed a lot of trans filters in my day and never have I had a problem like I have with this TH400. I think I amgoing for a change-200R4 overdrive.

Smokehouse69

I just did a complete reseal/gasket job on mine, I also replaced the fill tube because the end of it was out of round. Correctly torqued the pan gasket, and it still leaks. No as bad as it did, but bad enough that it pizzez me off!
My next trick is to try double seals at the shift shaft and RTV around the fill tube, those two places are the leaking points.

Cookwithvette

This is good to hear. I'll just keep a spare bottle in back and check the fluid every month or so.

Thenk you very much guys. :cheers:

70ZZ3 96LT4

I have a original owner 70 and the best thing I ever did was buy a new transmission pan from GM for my turbo 400. The replacement pan is a heavier guage of metal and sure does a better job of sealing around the edges. I have experienced no leaks or seepage like I put up with for years. I changed it out about 15 years ago. I also removed my 400 about the same time and took it to a transmission shop and gave specific instructions to only change the external seals. (Front seal, rear seal, and transmission selection seal). No leaks from these areas. I also put in a rebuilt torque converter because my original had a very slight wear ring from the seal.

Dr Z

Another issue is related to the long time the car was not moved. Mine does show a small leak now after the winter "vacation". I have had it out twice in the past two weeks - no more leak.
My interpretation is that over an extended period of time all the fluid finds it way down into the pan and rises to a level where there is some leak. When the car is being run, fluid dirtubets through the tranny and does not reach the leaking level.
Maybe I am way off, but it has been that for me the last two winters.

Cheers,

Chris

virtue4u

I just finished an inside car show over concrete pavement. When the car show was over and the cars moved out I noticed that a few C5s were already leaking. Leaking from the factory is not normal; leaking for a 25 year old car is normal. Except for the front main seal, almost all transmission seals can be changed without removing the transmission. I slowed mine down to where I have to put fluid in about twice a year.

NHvette

Hmmm - can't locate my B+M transkit directions - but .....

I recall that the different tranny fluids had a difference in the amount of
rubber swell that they produced. Depending on the fluid type, the seals
would absord a certain amount of the oil into the rubber. If memory serves me,
the Type F fluid gave the most swell. This could be the answer to perpetual
seal leaks - other than replacing the yoke or shift selector shaft.

Type F fluid will also give firmer and faster shifts - compared to the Dexron
spec'ed fluids.

I will keep looking for these specs. :seeya