tranny fluid darkening; low miles

[cf99]

Greetings, new to the forum.

I have a 2001 V6, AT with very low miles (a little over 20k). I'm the original owner so I know the car has not been abused. The transmission fluid (still the original factory fill) is beginning to darken. Given the low mileage, that doesn't make sense. Can the fluid darken strictly from its 10 year age? I searched but didn't come across an answer (probably because it's rare for a 10 year old car to only have 20k miles).

Also, I'm confused by something else I've read in searching the forum. Is it correct that the 2001 V6 AT camry (mine is a Japan-made VIN if that matters), the differential fluid and the tranny fluid share the same fluid path?

I've not heard of that before so it sounds odd. I thought generally speaking differential fluid was a much heavier viscosity than tranny fluid.

Thanks

[projektvertx]

Fluids do have an age limit. So I guess yes, your fluid does need to be changed if it gets too old, even if you haven't driven the mileage. I would just do a fluid exchange, and not a flush.

As for your second question, yes your differential and your transmission share the same fluid. You can drain and fill the differential fluid seperately via it's own screws if the need be though In most cases, you are right, they are seperate and the differential fluid is much thicker i.e. my dad's RL's differential uses 75W90 gear oil

[cf99]

Thanks for the quick reply and detail. The pan gasket has deteriorated and is beginning to seep (it doesn't drip yet, but I'm sure it will start to) so I am going to have the gasket replaced.

I was planning to have it flushed since they'll be removing the pan and all. I figured if the fluid is breaking down, best to get it all out of there and start fresh (even tho the flush costs more) rather than just diluting with new fluid.

Is it strictly for lower cost that you recommend drain and fill only? Maintenance on this baby has been so low over its life I figure I can spring for the extra, but if there's really nothing to gain by the flush, then it's truly a waste of $. Am I truly wasting my money with the flush or is there some benefit.

Thanks.

[cf99]

related to the flush, if I get the full tranny fluid flush, will that automatically flush the differential as well, or do I need to ask specifically that they drain the differential via the drain plug, in order to get all the fluid out of the differential?

[projektvertx]

A flush should empty the differential, however, I would advise against a full flush. I've heard of horror stories related to transmission flushes. I would do a drain and refill, replace the pan gasket, and do a drain/refill cycle a couple of times until the fluid comes out roughly the same color as you the one you put in. Seperate each drain/refill cycle by about 300-500 miles. That should switch out the differential fluid as well, and would avoid the flush.

Also, there is a crush gasket for the transmission drain pan screw which you should consider getting as well. Best of luck to you, and report back to us

[redtigerrocks]

My transmission fluid was dark @ 175k but after the fluid change, the color is still the same as it was before the fluid change.

[projektvertx]

Originally Posted by redtigerrocks

My transmission fluid was dark @ 175k but after the fluid change, the color is still the same as it was before the fluid change.

With a single drain/refill, on a V6, you only change about 3 quarts. The dry system capacity for everything is about 4 times that. Hence why you should drain/refill multiple times

[cf99]

Just to close this out and for future reference, I ended up just getting the drain and fill (pan and differential) plus a new pan gasket. The filter/screen was fine so was not replaced, and they said the inside of the pan looked good as new. They charged me $125 for 5 qts of dexron III + gasket + labor, plus a 5% shop fee. In about 6 months I'll do (or have done) another drain and fill, and probably 1 more after that. Thanks for the help.