Well i used my l460 to test some theorys,about syn trans fluid.at 500 miles i flushed out reguler dex merc with mobil 1 syn trans fluid.I got a nelson tune with 100%tq mgt removed and installed, all my mods at once.Okay now i take this thing to 6100rpm in first and 2nd gear at least 2or 3 times a day.Also have used allens nice shift into od at 56oo rpms at WOTat least 4 times.Tow a 20ft lund boat.And show it no mercy.Launch in 4hi etc run in autotrac in the rain at 90mph plus. So today i drop pan at 23405 miles, and was amazed,there is very little metal on magnet Im sure someday it will go but who cares for the amount of abuse i show it.And it helps my brother is service mgr at chev

 

i think it will take a lot longer for wear to show up due to a tune. as long as you keep up the maintenance you will be ok.

 

After considering the synthetic myself, and doing an extensive search on it in the transmission section of this forum, I decided its not for me! Glad you are having good luck, and glad your "mobbed up" with the service manager!

 

never really liked synthetic tranny fluid. none of the tranny builders i've ever talked to recomend it either. you don't want something really slippery in an auto.

 

I thought synthetic tranny fluid was a no no in the 4l60e's. Excesive slippage.

 

the builder i used has used synthetics in all his trannies and diffs. he has been building 9 second cars with 4L60's in them for years. i have synthetic in mine with no probs.

 

There's a guy with a radio call-in program (550 AM Sat 11-2pm) in San Antonio who's really knowledgeable and is a GM freak,too. Also has a shop with a Tech 2 Diag. computer. He's big on synthetics in engines and tranmissions,too. He talks more about Amsoil,because I think he sells it, but likes M1 also.
I've used the oil for many years but not the atf,yet.

 

whats up fellow bowtiers,,,,,,,,,5.3 4l60 short bed single cab here with a hand full of bolt ons and a nelson tune......my experience with mobil one synthetic wasnt very good ,,,,,,,,,,flushed out gms tranny fluid round 20k,,put in the sythetic and it slipped like crazy,,,,,,some folks might have good luck with it,,but not in my case,,,the product i used that works well for me,,,,,is regular atf plus a quart of lucas transmission stuff,,,,,,works great for me,,,,,,,,,,,,anyhow,,,,,,,have a great day guys,,,,,by the way,,,,,,,,,im at 51k know and no problems,,but fixin to get a yank 26/30 converter and trying to decide about getting a "bullet proof" trans from an aftermarket vendor,,but dont know which one,,,,,,,,,im installing a nx nos kit right now,,,any suggestions ?