Changed burnt ATF transmission fluid ?

[rkpatt]

I am taking over an elderly family member's 1993 Camry 4 cyl wagon with 121K miles . The engine oil and filter has been changed every 3K miles and I didn't see any signs of sludge through the filler hole .

The transmission fluid servicing history is a different story . The transmission fluid smells a little burned and the color is very dark . There are no records for any ATF changes . The transmission is working perfectly . My gut feeling is to pull the pan and change the filter then flush the transmission via the cooler line like I do on my other vehicles that get regular servicing . I have been warned not to do this by one mechanic (something may get dislodged and kill the transmission ) . Any opinions here ? - Thanks

[dz63]

Back up one level in the TN forum and go to the Camry General Discussion Forum, then do a search on "transmission flush". You will get a wide range of opinions, but the general concensus seems to be flush, even in your situation.

[islandboy57]

I side with the people who say to change it regardless. Personally I don't see how continuing to use burnt ATF can be better than getting fresh fluid in there. If the tranny goes after an ATF change/flush, it was on its way out in the first place.

I just did my first ATF change (drain and refill twice) on my own Camry six months ago, and I did my mom's gen 3.5 last month. Soooo I'm not sure what my interval is just yet other than checking the dipstick from time to time. It made a difference in my car, but I can't really feel a difference in my mom's car. The V6 + 4spd auto in the gen 3.5 still shifts like butter anyway.

BTW, welcome to TN! Enjoy the "new" Cam, I'm sure you'll get much use and enjoyment out of it.

[toyomoho]

Dexron can smell a little burned and still be OK, the issue is the fluid is black and has 121K miles.

If you don't change the fluid the odds are high the trans will have problems requiring a rebuild.

If your not up to flushing pull the pan and clean screen, magnets and pan. If you find a lot debris in the pan you may have a problem in the works.

If you not up to flushing, do 4-5 drain and refills with some driving in between. The pan holds about 2 quarts, about 4 are in the torque converter.

You can also purge the old fluid. After cleaning the pan refill with new fluid. Disconnect the return line from the trans oil cooler to pan, start engine and allow fluid to drain into a container. Refill and repeat the process until clean fluid comes out.

Have someone at the ign switch to turn engine off when the fluid begins to stop coming out, you don't want to run the trans with out fluid.

[touringcamry]

Originally Posted by toyomoho

You can also purge the old fluid. After cleaning the pan refill with new fluid. Disconnect the return line from the trans oil cooler to pan, start engine and allow fluid to drain into a container. Refill and repeat the process until clean fluid comes out.

Have someone at the ign switch to turn engine off when the fluid begins to stop coming out, you don't want to run the trans with out fluid.

On my 2000 I4, the fluid would start to foam after about 15 seconds or so, so probably it's best to run the car for maybe 10-13 seconds at a time. I think I got about 1 to 1.5 quarts each time.

[ShawnM]

The thing with an old high milage trans is that the varnish left by the old burnt up fluid actually helps seal up the internals. New fluid can clean away that varnish build up and cause internal leaks which lead to slipping during shifts. Ive seen some that failed after doin a trans service and ive seen others that ended up being fine. The way i look at it is if there is a lot of varnish built up inside it its probably not going to last very long anyway so might as well do the flush and see what happens.

[rkpatt]

Thanks for the replies so far . I guess I have to decide what to do if the transmission happens to be one of the ones that fails after an overdue fluid change .

[kenwoodrunner]

try using a low detergent mec/dex3 such as maxlife. mike

[rkpatt]

That is Interesting . I thought that all ATF was high detergent .

Originally Posted by kenwoodrunner

try using a low detergent mec/dex3 such as maxlife. mike

[toyomoho]

It is.

Maxlife appears to something different. See link below:

http://www.valvoline.com/pages/produ...asp?product=73

[kenwoodrunner]

i know all atf labeled "high mileage atf" has lower detergent formula.

[kenwoodrunner]

here is a pdf on maxlife high mileage atf. not maxlife atf with stop leak! two totally different products!

Link:
http://www.deckmanoil.com/downloads_...Life%20ATF.pdf

[Andrew Liu]

I just changed my transmission fluid today, used the coolant line procedure.

The fluid before I changed it was BLACK, looked like used motor oil. Took 9 qts. of new ATF to remove all the old fluid.

Shifts are a lot smoother now, after flushing, despite the condition of the fluid beforehand.

[rkpatt]

That "maxlife atf with stop leak!" has more solvent to soften the seals . I imagine that loosen up a lot of crude too .

[camry6]

The best way to handle this situation is to do a double change of the fluid using a high-mileage fluid. Before filling for the last time, pour in a full bottle of LUCAS transmission treatment. It will not void new car warranties, so it certainly won't harm your transmission. This stuff conditions and softens the seals in the trans and will keep it alive. I once lost reverse completely (due to internal leaking seals) in my '93 camry. I changed the fluid and added two bottles of LUCAS to the trans. after about 2 months of normal driving, reverse was almost completely restored (except for a little shudder upon engagement). I put 30,000 miles on it until I found a good used replacement. It never quit, I just felt more comfortable with a known good transmission in my car, rather than looking at it on the garage floor. After putting it in, I added a bottle of LUCAS to keep it alive- so good so far.