Here is the old saying. If you never changed your trans fluid and it is really dirty, new fluid (with their detergent) will clean the residue from the clutch plates and cause it to slip.
To be honest, I have heard it many times, but in 30 years of working on cars (including transmissions), I have never seen it happen.
If the fluid is discolored and not bright red, I would recommend having it done.
Thursday, January 27th, 2011 AT 7:50 PM