I'm doing a late model (99-01 style) 5.3L motor & 4L60E tranny swap in my Jeep TJ, and I'm exploring my options as far as transfercases go.

I was planning on keeping the 231, but to keep it, I'd have to spend $700 in adapters from AA. Not worth it IMO, as I'd still need to spend another grand or so down the road to make the thing worthwhile (4:1, SYE etc).

questions:

What transfercases bolted up to the 4L60E in the 99-01 range? I've been told NP242, 241 and 246 (electronic push button?). My searching isn't turning up too much info.

Which ones are worthy of a daily driver Jeep that will see some good trail usage (nothing too radical for now) ?

Any other recommendations?

My concerns are:
1- strength
2- low range gear
3- overall length

Thanks for any help guys..

a heep with chevy running gear? never thought i would see that:rolleyes: :flipoff2:

4WOR had an article a few months back deatiling all of this stuff. check their website or your stack of old issues.

http://www.zr2.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=13;t=001195 (tcase info)

since i can't tell a tj from a yj to a whatever j, I'm guessing you need a passenger side drop.

Ok, the late model 4x4 4L60e's have 6 mouting bolts on the output side. That might complicate the adapter problem. And otherwise i can't help you. If you need the diff on the drivers side i can help


Greg
408-685-6726

Thanks for the info guys.

TJ = Wrangler

It's a driver's side drop, so you can help me ;)

It is a late model tranny with the 6 bolt output, which is the difference between it and the older 700's/4L60's and is the complication here it seems. I thought about going to an older one, but I want the computer controlled shifts/TC lockup, so I can play with those in the calibration, plus I don't know if I'd run into problems bolting an older 4L60 (or an older 4L60E) up to my motor. Should be the same, but I believe my tranny guy warned of differences.

I should see if I can get the output flange changed to the older 4 bolt style, it might make life easier.

I think all the other t cases you lister earlier are passenger side cases ,but not sure. I will tell you what I know.

I don't know what the front of a jeep 231 looks like so I will give you the info for what I have on my s-10.

My s-10 came with an electronic 233c. "screw that, I want manual" so I bought a 231c (c stands for chevy) which is manual.

Oh crap, the adapter for the 231c has 4 bolts, mounting holes for the shifter, and is 2.5" shorter than my 233 adapter (the output shaft on the 4l60E is longer)

Enter adapter. I stumbled on this adapter by accident. A company called Jags That Run (jtr.com i think) made an adapter for the 6 to 4 bolt conversion for the exit cone on 700r4's. I guess an improvement for 2wd or whatever.

ok pay attention:

231c factory adapter (2.5") + JTR adapter (2.5") = (5") factory 4L60E to 233 adapter. Measurements are the length of the adapter.

Also a friend of mine put the Heep SYE kit in a 231c so they're easily interchangeable. I don't know if the 4:1 kit will work in the 231c but with the OD on the 4L60E, you can gear the diffs down pretty low. I'm going with 5.13's and 35's.

I was just thinking about the 4L60E too. It is an electronicly shifted tranny. You must have the computer. A friend of mine has this tranny and the connection for the induction ring (the ring that tells the rpm of the output at the end of the t case), well the connection fell off and the tranny was stuck in second. Imagine trying to wheel in second gear:eek:

So for this tranny, you will have to have the computer, power to the computer, and at least the wires from the pickup to the computer

wheewww