Changing transmission fluid
My 2010 silverado is creeping up on 30k miles. I pretty much only use it for towing or hauling something. Tranny temps while towing are typically around 200-220 and some minor runs at 235 on large gra...
Forum Discussion
BurbMan wrote:
IMO, it's more valuable to drop the pan and change the filter than it is to flush 100% of the fluid. You will have 3/4 of the fluid replaced by dropping the pan, and the remaining 25% of teh old fluid won't hurt anything.
I disagree and don't think your numbers are correct and quoting numbers that are complete guesses are dangerous and often inaccurate as I think this is the case here so I have provided at least one reference in my reply here that contradicts your assertion. According to another thread LINK
04 service manual for the 4l60-4l65-E says 5 quarts for pan removal. Complete flush, including converter is approx. 12 quarts.
Therefore your simple pan drain and refill will get less than 1/2 of the old fluid out and probably closer to only 30 to 40% and not anywhere near your 75%. In fact I bet you will be on the low end in your 8.1 vehicle since I bet the TC alone has a lot of fluid. My 4R100 FORD tranny as an example holds 17qts and the pan around 5 to 6 with almost 12qt being in the torque converter.
IMO doing a complete fluid change is the only way to go and is very simple by disconnecting the rear line on the 4R100 and using the trans itself to pump out the old fluid. This way you change upwards of 95%+ of the old fluid. I'm not expert in other makes of trannies, but I bet there are procedures similar to what we FORD 4R100 owners use that will change an extremely large percentage of fluid.
Larry
