i see everyone putting in ATF+4, but what about Mobil 1 Syn ATF? in the tranny....bad idea? just curious

 

I just did a tranny service on my truck today.

Removed the pan, adjusted the front and rear bands, changed the filter and FINALLY I put in a dang drain valve in the stock pan. I was kicking myself for not doing it last time.

Now I can flush out my tranny the easy way!!!. Run it for 15-20 minutes....drain out 4 qts....put four back in, run it for 15-20 minutes and do it again. I put on a petcock with a nipple on it so I can put a short hose on it and drain it right into an empty milk jug for disposal Takes about 10 minuts or less. The only downside is that I will only be able to do about 4 qts at a time BUT absolutely no mess. I put the drain valve on the back side near the rear band adjuster so I don't have to worry about something hitting it and breaking it off.

So from now on, I'll drain out 4 qts and replace everytime I change my oil. That might be a little much, but I'm fanatical about maintenance.

 

I cant speak for the 48RE, but in a 4L60E, I lost two transmissions in 10 months with synth fluid due to the clutches slipping. Switched over to a standard ATF and no problems afterwards until I broke the drum.

 

ATF+ 4 is the only fluid approved for a 48E. It is synthetic.

 

Yep, putting in anything else will make you regret it in a real hurry.