I wish my tranny would just last 10k I haven't had one last over that.

 

Fresh new ATF is a harsh substance. It will break down old 140k tranny clutches in short order. When I was in business I wouldn't touch a a vehicle (for a trans service) that had more than 70k if it had never been serviced. There is a chance it would be OK but if it is working fine now I would not advise messing with it.

The comparison to changing the oil in the engine is not valid because of the friction material factor-engine bearings don't dissolve with new oil like trans clutches do with new fluid.

 

tell him not to do it, my friend just did it on his 00' 5.3 w/120kmiles and now his transmission and messing up right after the oil change.... it still runs but he said it kind of revs up too much when trying to shift....

 

[QUOTE=1slow01Z71]It wont screw it up by putting new fluid in it.

not true! ATF is full of detergents that can ultimately "clean" the tranny causing seals to leak, varnish to break loose, etc. leading to failure. granted, it may not last long anyway.

 

[QUOTE=Texas Terminator]Exactly... and also. If it hasnt been changed for 140k, than possibly the gears are catching on the dirt or grit that the old fluid has created and you may have a little bit of a slip when you go and put new in. Just my .02, ive seen that happen before, but it was in a ford, so who knows, lol. I'd see what a tranny shop says and go from there, hell let them do it and see what they can **** up and than they'll have to replace it, lol.