Three weeks ago I changed trans fluid (4spd Muncie) in my car from the nasty old oil that was in there to Pennzoil synchromesh fluid. I parked the car and everything was perfectly dry underneath.
The car did not move until yesterday when I drove it to the gas station, less than 1/4 mile away. After I got home, I looked under the car and there was a huge puddle of oil under the trans. So I put a pan under the car to catch the oil, and in 24 hours it leaked almost half a qt of oil. Come to find out it is coming from the left side axle seal. Now my question is, would the new oil cause the seal to rupture and why? Has anyone heard of this happening before?
Plus the car has only been driven 10 or so miles since 1994. Could that be related? or maybe it was just bad luck.

I don't think that the Penzoil had anything to do with the leak, unless it washed away some dirt that was the only thing keeping the oil in. No doubt the only 10 miles since 94 had something to do with it.

What TopNotch said. 10 miles in almost 20 years is not very healthy. Lots of time for stuff to dry rot.

Sounds like the car has been missing you and is crying tears of hapiness. No doubt you should replace her contacts and hand her a tissue!

Synchromesh is pretty thin stuff for what it does....it probably cleaned out some junk from the old fluid.....exposing a problem that you would have had anyway......bad seals.

Its possible that it was too low on oil with the old stuff? Properly filled, at rest, the 4spd has oil up to the axles - above the seals!

Synchromesh won't cause a leak, but changing the fluid can dislodge sludge that was plugging a leak, letting the clean oil flow right through.

quote Originally posted by katatak: Its possible that it was too low on oil with the old stuff? Properly filled, at rest, the 4spd has oil up to the axles - above the seals!

Since I am having the same problem/issue, I figured this to be the answer. After refilling my 4spd trans I have the same leaking seals now.

For those of us who need to replace the seals the question arises . . . do we go with stock style seals or the replacement ones with the extra bearing? I have been reading via the archive about this and find mixed answers?

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I prefer stock style. The add-on bearings leaked for me.

Did you overfill? Proper level is still just below the seals.

Edit: With a Getrag. Not sure with the Muncie ??

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[This message has been edited by fierosound (edited 05-28-2011).]

quote Originally posted by fierosound: Did you overfill? Proper level is still just below the seals.

I put 2 qts in, I thought that was the spec. I cant get the vss out to check that way.