tranny fluid

[king bee66]

when i changed my clutch recently i noticed the oil was pretty funky. ive heard mixed opinions on what to do about it, some people have told me that if its not been changed in awhile its better to put the old oil back in, others have told me to change it regardless. what do you guys do?

[datzenmike]

Change it. Should be done every 30K. The sulphur anti scuff additives break down over time. 2 quarts of GL-4 80W90 should do it. Do not let some collage kid tell you that GL-5 is better.... It is, but contains 50% more anti scuff additives that break down and damage the brass synchro rings. GL-5 is for differentials that need this, trannys need GL-4.

 

Inspect the drain plug, it has a magnet on it that traps metallic debris. A black paste is normal, chunks and parts is not. Wipe off so you have a base line for your next change/inspection.

[king bee66]

there was a fair amount that i sifted out a month back while i was replacing my clutch, but other then topping it off with some new oil, i mostly put the old oil back in. i was told by a couple of people that if the oil hadnt been changed in a long time, it would be more detrimental to the tranny to put new stuff in then to simply reuse the old oil. im surprised noone else has ever heard to do this.

[Draker]

This applies to automatics.. I would put new oil in as there are no clutch packs to worry about blowing out. All metal gears in there.. you won't be hurting anything. Follow the advise that Mike gave you.

[king bee66]

ah, thanks

[datzenmike]

This applies to automatics.. I would put new oil in as there are no clutch packs to worry about blowing out. All metal gears in there.. you won't be hurting anything. Follow the advise that Mike gave you.

 

 

I've heard this also but could be urban myth.

 

Someone has an auto that's starting to act up and this is the only reason for checking the fluid as they don't know when it was changed... maybe two owners back?? who knows, ... so they figure "Hey, as long as it's working, meh, I'll just leave it alone.". So now they panic and replace the ATF because the old stuff is funky black and burnt smelling. Two weeks later it blows up.

 

SO...

Does it finally blow up from years of neglect of proper maintenance???...

OR

It blows up from new ATF??? that just happens to be put in near the end when it's too late???

 

The old fluid is burnt? Think about the fryer oil in McDees. Don't you think it will work better if lubricated by a proper ATF?

The old fluid is discolored (maybe burnt) or that's clutch material worn off from poor lubrication. This stuff is pumped throughout the transmission abrading small orifices, valves and hydraulic components.

 

 

My sedan's auto fluid is off color. Not black, just a dull brick red. It has about 31K miles on it so it's very likely the original and 38 years old. So this winter or spring I'm going to replace the ATF and filter and I'll take pics and see what happens. I'm not worried as I have at least two other good autos laying around.

 

BTW it shifts very firm at full throttle and hardly noticeable around town. I love it.

 

 

 

... but with my 5 speed goon..... it's different.

[Draker]

I've heard this also but could be urban myth.

 

Someone has an auto that's starting to act up and this is the only reason for checking the fluid as they don't know when it was changed... maybe two owners back?? who knows, ... so they figure "Hey, as long as it's working, meh, I'll just leave it alone.". So now they panic and replace the ATF because the old stuff is funky black and burnt smelling. Two weeks later it blows up.

 

SO...

Does it finally blow up from years of neglect of proper maintenance???...

OR

It blows up from new ATF??? that just happens to be put in near the end when it's too late???

 

The old fluid is burnt? Think about the fryer oil in McDees. Don't you think it will work better if lubricated by a proper ATF?

The old fluid is discolored (maybe burnt) or that's clutch material worn off from poor lubrication. This stuff is pumped throughout the transmission abrading small orifices, valves and hydraulic components.

 

 

My sedan's auto fluid is off color. Not black, just a dull brick red. It has about 31K miles on it so it's very likely the original and 38 years old. So this winter or spring I'm going to replace the ATF and filter and I'll take pics and see what happens. I'm not worried as I have at least two other good autos laying around.

 

BTW it shifts very firm at full throttle and hardly noticeable around town. I love it.

 

 

 

... but with my 5 speed goon..... it's different.

 

I have been told that the cleaning agents in new ATF delaminates the clutch material from the metals. If you don't change it often enough it will burn and deteriorate the discs.. then once you put new ATF they delaminate. I don't know the whole theory but I learned this while doing my ASE auto trans training.

 

My friend had an automatic Geo metro and he never changed the fluid in it. When he did finally drop the pan to do the trans service it was in very poor shape. He filled it up with the correct new ATF and drove it for about 2 weeks.. then he lost a few gears. Something like first and reverse.. (can't remember)

 

I dropped his tranny and installed another one for him. Then I took his trans to the shop and tore it down. It was exactly that... Clutch material litterally separated from the metals. Most of the material was still in the clutch pack, just delaminated.

 

So, there is a chance it was ready to go. But given the sequence of events and the timing.. and then physically tearing it down and inspecting it myself... I gotta say it was probably the new ATF!

[datzenmike]

OK then. Hopefully mine isn't that bad. It's old but not burnt or black.

[Draker]

OK then. Hopefully mine isn't that bad. It's old but not burnt or black.

 

This fluid was BAD... Burnt, black, ugly, and probably thicker than it should have been.

 

I think you're good... besides you are the tranny hoarder.