Thread: Tranny Coolers-

Originally Posted by h0wl0ngcanitbe

Scott can you elaborate on this? When I had my tranny fluid serviced at Jiffy what do you think they did? A flush? Since my fluid change ive had no problems and I was thinking about servicing the tranny again as I am about there again mileage wise.

I do not have a lot of experience with GP, but im working my way up. I have however been working on diesels and HD CVT transmissions for the last 2 years, and hears my 2 cents:
The reason not to flush an old tranny is that the material from the clutches has worn off of the clutches and is now in the fluid itself. A pan drop does not replace enough of the "dirty" fluid to kill the transmission after it is in this condition, because the remainder of the fluid still has enough friction material in it to grip and shift. A trans flush will completely remove all of the lost friction material (and probably clogs alot of the ports in the valve body IMO) and your clutches wont grip.
I have been told by GM for my 4t65 that at 75k the trans should be serviced (pan drop, filter change). after 100k, or "burning" your atf, your pretty much out of luck and you just got to limp it till it dies.

From experience...I never flushed the trans on my 3.4 impala, and against experienced advice i added lucas stop slip to it around 115k, and broke my imput shaft around 125k. Coincidence probably, but the main point is that it cost me 1800 to fix. Im pretty sure a TE performance tranny will run you about that much no including install.

My advice before this post turns to a book...dont add any performance parts or shift kits to this tranny, run it till it dies and then buy a new one with a new TC. Or sell the car while its still running and buy another GP in better shape!

Originally Posted by h0wl0ngcanitbe

Scott can you elaborate on this? When I had my tranny fluid serviced at Jiffy what do you think they did? A flush? Since my fluid change ive had no problems and I was thinking about servicing the tranny again as I am about there again mileage wise.

how many miles did your trans have when flushed? and had it been serviced before the flush in its life time?

i used to flush my 97 truck every year, i did put 30,000 hard miles on it a year, and that tranny lasted a long time before it let go. i also owned the truck from new.

at this point if your fluid is still nice and red looking, service away. cant hurt if its due, like 50,000 miles since the flush. some like to do it every 30,000 miles, 50 the norm tho.

what happens is the old burnt up dark fluid is full of clutch material, its what is keeping the trans working. if you flush all the old fluid out, and replace it all, the tranny wont work 90% of the time. most jiffy lube places if you have over 70,000 miles and have dark fluid they wont flush it. if you insist they make you sign a waver so you cant sue them if it dont drive out of the shop or fails later on.

had a friend who was the manager at one of these places. i was hanging out there one day and hes like watch this crap. walk out to a customer comes back with a signed paper, says this car will need a tow truck, the owner wont listen, they did the flush, and then he paid, put the car in gear and nothing. next call was for a tow truck.