42RLE Quirks?

[k99jk99j]

Here's one: 2003 KJ Renegade/77k & 42RLE...Zero issues Friday morning.

Sent it in to a friend's shop to change all the fluids. New trans filter, trans pan & Amsoil ATF. Disconnected the battery for 15 minutes to reset the TCM values.

Friday afternoon, it is absolutely fantastic and better everywhere w/one exception: When downshifting while on the brakes at about 15mph, I get a VERY hard downshift. Seems like it only happens at high vacuum conditions as it does not shift hard while downshifting at that speed while accelerating.

Any thoughts?

your problem is the friend did not do a quick learn on the trans after the new fluid. when the fluid was changed the new fluid has different viscosity because it is newer and has not sheared, also the friction modifier pack in the fluid was replentished.

how do you correct the situation?
1 take it to the dealer for a quick learn (1 hour of labor)
2 drive it till it disappears. it will take around 70 full warm up key cycles and maybe up to 700 miles, untill the tcm "adapts" to the new fluid. mike

p.s. disconnecting the battery is not enough to flush the tcm

 

[PanAmerican]

The reprogramming did it!

Thanks for all the help!

 

[tjkj2002]

ATF+4 (is synthetic) and has advanced friction modifiers. The Amsoil may not be fully compatible and could lack the complete friction modifiers.
Short of changing out the fluid and getting proper +4 fluid in there, you could add some additional friction modifier/Lubegard : I am pretty sure that would smooth out your shifts immediately. Your Amsoil will now perform like ATF+4.
Link: http://www.lubegard.com/~/C-113/LUBEGARD+Platinum+Universal+ATF+Protectant
After adding ensure you have correct level and reset thru battery again.

That stuff does not make any ATF the same as ATF+4.

The official list of approved ATF for newer Jeeps including the KJ and KK,tested and approved by Chrysler.

http://centerforqa.com/licensedatf4brands.html