I am confused as what is the proper method to flush the transmission oil. Tell me if this is the proper method.

1. Unbolt drain plug from pan and drain transmission oil. This should drain about 3 to 4 quarts. Replace drain bolt.

2. Disconnect the transmission oil return line from radiator, and replace it (connect to the raditor) with a clear piece of hose. Aim the clear hose into a bucket to catch the old oil.

3. Start car and old oil will drain from the clear hose. While oil is draining, fill with new oil into the dipstick hole.

4. Keep flushing until new oil comes out.

If this is the proper method, then my question is: Why is it necessary to first drain the old oil from the drain plug on pan if you're going to flush it through the transmission return line? Can you skip step 1 and just start from step 2?

Also what is the recommended tranny oil. I'm considering going synthetic. I have 68k on my Maxima, is it still okay to switch to synthetic with 68k miles? Mobil 1 or Amsoil?



Thanks,

 

I think it's faster to drain the tranny and put 4-5 fresh qts. in it before you start to use the cooling line. Either way should work fine.

There wouldn't be any problem whatsoever switching to a synthetic at your mileage, even Mobil 1 Others have switched at much higher mileages and will surely post here as well for an unbiased opinion.

 

You might be wasting a lot of tranny fluid this way though. I think that many Midas's (Midi???) have trans flushing equipment, and it uses like 14 qts total. They usually charge $69.00 to $99.00 to do the service (we sell the machines at work).

If you got a drain pan that'll hold all that, you're welcome to try, but it ain't fun carrying 4 gallons of hot tranny fluid, not to mention the expense for all that fluid.

Too, don't let the level get too low, as running the trans too low can damage it.

 

Where can I take the old transmissin oil to be disposed of? Do the local oil change shops take them? Does it cost anything?

 

Go to a shop that has the "T-Tech" exchange machine. Like Midas or Jiffy Lube. We build them in Minnesota, there the best!

 

you can take the old fluid to your local Autozone