Transmission Fliud Question?
Thread Starter
Instructor
Joined: Nov 2008
Posts: 106
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Transmission Fliud Question?
Our 1980 L-48 has I believe the 94k miles on it, original, I hope. We just rebuilt the engine, awaiting some final corrections on the wiring on that, so it is still sitting. Should I change the transmission fluid at this point( hopeing 94K is the correct mileage) or just keep it full and drive it. I have heard that changing the fluid after it has been in a transmission for so long could cause more problems than just leaving it alone. Thinking it has never, ever been changed out before, should we change it out now after not so much the 94k but the 28 years? Transmission shops from our experiences, make me nervous is a nice way to put it.
Melting Slicks
Joined: Apr 2008
Posts: 2,625
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From: Russell Ontario
St. Jude Donor '09
Changing fluids never hurts , the question is , what did the fluid look like before the change, and what was in the bottom of the pan! It's normal to get very fine "filings" in the bottom of the pan, some will get stuck to the magnet! the fluid should have been reddish in some cases dark brown red, that is a sign that the oil has been there for a while, still no harm .But if you get bigger filings or small chuncks , then it's more of an issue! Ron.
Race Director
Joined: Mar 2006
Posts: 14,112
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From: Florida
Don't think there were magnets in the old trannies.
Last one I took the pan off of had the filter paper hardened and broken into pieces. So there was no filtration and who knows how much of the hardened cardboard went thru the pump.
Still works well with new filter, fluid and magnet added.
Make sure to use the old Dexlll fluid and not a later synthetic. That's where most of the problems you hear about stem.
If you can, weld a bung in the pan for future drains. Makes life a little easier.
Last one I took the pan off of had the filter paper hardened and broken into pieces. So there was no filtration and who knows how much of the hardened cardboard went thru the pump.
Still works well with new filter, fluid and magnet added.
Make sure to use the old Dexlll fluid and not a later synthetic. That's where most of the problems you hear about stem.
If you can, weld a bung in the pan for future drains. Makes life a little easier.
Thread Starter
Instructor
Joined: Nov 2008
Posts: 106
Likes: 1
That answered my question fully. I have not dropped the pan yet but the fluid we saw when we were taking the motor apart was a real red color. I will change it with the old style fluid, and get a drain put in it too. That is a very good idea! I really appreciate your help on this, I am really trying to do it up right. I tend to question most of the stuff I hear from mechanics I do not really know. There are very few I trust that I do know , ! 
Thanks again,
Have a great day and a wonderful Christmas!
Ray/aka/Pa
Thanks again,
Have a great day and a wonderful Christmas!
Ray/aka/Pa
