Since I bought the car, I have been changing (via the drain plug) 4.5 quarts of transmission fluid. I drained 4.5 quarts and then refilled with 4.5 quarts of Mobil 1 synthetic ATF. This was done at 15K and will be done again at 25k or 30k. My question is, since I am doing this...do I need to have the shop do a trans flush at 30k?

I know the fluid will be good, but is there any benefit of having them do the flush (wash out contaminants, clean out crust from lines, etc) or should I just continue my schedule of drain/add every 15 to 20k?

The reason I started thinking about this was due to the new RX-8 being released. From what I read, its engine oil is alot like our transmissions. There are other areas that hold oil, so on a drain/refill you only get about 3.5 quarts of the 7 quart capacity.

 

I would keep doing what you are doing, only next time (25k) take a sample of the ATF and have it analyzed by Blackstone. That should let you know if the next drain should be a full flush.

 

Cool thanks!

We took my wife's 93 Sable to a QuickLube place to have the transmission flushed (she had a rebuild about 20k miles ago). Anyway, I was surprised to see that all the guys do is hook up a big black box with two lines (one on the outgoing tranny line and one going into the cooler) then start the car. WTF?

I thought the machine pumped the fluid in reverse, there by cleaning the screen in the process. At least, that is what Ford told me their machine did on my former 97 F-150 at it's 30k service.

The QuickLube guy could not get the inlet tube hooked up and was spraying fluid everywhere. I took the car home. Not having the courage to do this to my 2k2 Maxima, I gladly told her I had full confidence to do the flush on her 93 Sable.

Took about an hour and 11 to 12 quarts of fluid. Pulled the return line and emptied 3 quarts into a bucket, refilled transmission with 3 quarts, repeat until done. The fluid was brown and quite thin. Shifted much better when all was said and done.

 

This is the biggest issue with the flush machines. They do not clean the screens. Do you really think it would be a good idea to flush all the crap that the screen caught back through the system anyway?

The ideal way to service the transmission, especially higher mileage ones that have been neglected, is to drop the pan, clean the screen and then run the ATF through like you described.

 

Although I agree, I think you missed what I said. I was told the system pumped new fluid in the REVERSE of the normal flow. Think about it, that would pump whatever was in the screen back the other way. Now, I know the screen is at the bottom of the gears (now I do) but at the time, for all I knew, the hose went down to the screen.

I agree, the best procedure is to maintain the system regularly.


Bill,

OT, I picked up a 5 gallon jug of Mobil 1 during "Tax Free Days" at Wal-Mart for $18.88.