So ,,, a question/looking for some direction ,, I am about to pull my 4l65E and have it cleaned and freshened due to my own dumb-assery(Fuid level low , dipstick far from correct... ) 3-4 slippage ensued..

I am NOT literate in the internals, I'd like to have a shop handle it. (My life would not allow me to finish this in any kind of reasonable time frame.
I wish I did,, its one of the few things I have not messed with on a vehicle.. )

My setup:
Jeep YJ swap, 5.3, Holley Terminator X max ,,, Lokar sport shifter, gives me O-3-2-1 + a tap shift functionality.
I originally had a basic 4l65E rebuilt with the standard parts to make it a nice durable trans, but after the fact realized that re-builder maybe didn't really take my use case in to account. I wanted to basically be able to put it in drive on the highway, and only use the tap shift off-road for the most part. This is a my fun vehicle but I often take off on multi day trips with it. It does seem to slow down nicely when it downshifts.. so I'm thinking its not far off from whats described here.

As I've read more,, and managed to dig up guys running offroad in jeeps with the GM transmissions (Mostly 4L80)
The serious guys are running full manual valve bodies and non lockup converters with north of a 3800 RPM stall.
I haven't wheeled mine yet with the truck converter that's in there. So "while I'm in there" I'm trying to pick a new converter, looked at a Hughes, contacted a couple site sponsors. Didn't get much back other than them telling me Hughes makes good converters..

Now I'm not doing competition, I just want it durable and as immune to mistakes as I can make it.
It sounds like the mod to keep the over-run clutches in play is a good idea for my use if I will want automatic shifting.

Also side thought, if I disable converter lockup when in manual shift / tap-shift mode that should get me close to the manual valve body but let me keep lazy mode for the highway? (I have a larger fan equipped external cooler to help control the heat.. )

I would have gone 4L80 but I just don't have the length to get away with it.. And I don't feel like stretching my jeep ... Physically it is agile and lets me crawl through tight spaces where long wheel bases just can play.. I'm at about 320 HP in a < 4000 lb jeep, so not expecting to just blow the trans even though its a 4l60/65 version. (Barring any moments of indiscretion.. LOL)

Thanks in advance for any thoughts on how to make this little beastie behave, trying to balance it all .. without tearing it out too soon..

 

@pdxmotorhead EDIT: The 4L80E T-Case Adapter IS Shorter by about 2".

So the 4L80E would actually be ONLY 2" longer.



Two things:

-#1 =The 4L80E (4X4 No Tail-Housing used) is ONLY 4" Inch Longer than Your (Gen-III/ IV Type Case) 4L65E Transmission (and I believe the Adapter Housing is actually SHORTER)!
-#2 =Doug (TruckDoug: Member on our Forum) lives near you and offers some great 4L80E Action!

 

I hear ya,, 4" doesn't sound like much, but in a YJ its the break over point, I had to buy a specific 400 dollar tail slip yoke eliminator kit to shorten what I have by 3" to make work. I'm running the shortest adapter combo I could find and its all GM. Are you saying no adapter for the 4l80?? I'm running a NP241 Driver side tcase. My rear driveline is about 16" right now. which lets me get full travel in the rear. (I'm on leaf springs still.. )

I'll get a hold of TruckDoug , one of my direct issues is just finding a builder.. I have a guy I've used in the past and he's good to deal with but I've only done manual transmissions for years.. I did the auto because I wanted something less on-off than the clutch offroad, and a manual trans that could do what I wanted was going to be in the $5600 range without bell/clutch etc..

Thanks a ton for the feedback! more exploring to do..

 

Got it moved! thanks!