Any differences between transfer case from an auto versus a manual?

[TJ_2000]

Notice both of your transmissions were manuals which would use the same length input shaft in the transfer case. The length difference matters a lot when the transfer case was made for an automatic but the transmission is a manual or visa versa. Tcase input shafts made for manual transmissions are, generally speaking, too short to seal an automatic transmission's output shaft.

I did a transmission conversion from a manual to an automatic. I learned about the difference in 231 input shaft length differences for auto vs. manual transmissions when my new 32RH automatic leaked ATF like a sieve out its output shaft because my manual-style 231 tcase input shaft wasn't long enough to seal it. I ended up having to install an extended output shaft into the 32RH so it would seal.

According to Novak. The NV3550 used a long input shaft and the AX15 used a short. I started out with the 3550 and went to the AX15. Again. No issues.

 

[Jerry Bransford]

For someone who has never did anything this mechanical, I would like to be able to have it out in front of me and have plenty of time to be able to disassemble and reassemble it. I have heard both sides of it being easier doing it in the jeep and doing it out.

I had never replaced a SYE my first time doing it with the tcase mounted in the Jeep either. Removing it would have just made the job more difficult without any real benefit. Friends advised me to do it with the tcase still mounted to the transmission and I took their advice, I'm glad I did as it was a relatively easy job.

 

[Jerry Bransford]

According to Novak. The NV3550 used a long input shaft and the AX15 used a short. I started out with the 3550 and went to the AX15. Again. No issues.

Think about that... a transmission's input shaft inserts into the opening in the flywheel bolted to the engine, not into the transfer case. It's the 231 tcase that has different input shaft lengths available depending on what transmission it gets bolted to.

Not to mention the OP has an automatic transmission. What fits your NV3550 or AX-15 has no bearing on what fits his 42RLE automatic.

 

[Blackjack]

You must not have read the thread. I am buying it because I am wanting to put a Slip yoke eliminator in and want to be able to take my time and do it outside of the jeep and still be able to drive my jeep. And i will more than likely just buy a new input shaft and sell my old transfer case to recoop the money.

Well that will work if you are ok with the expense of the input shaft.

 

[S.McArthur]

Has anyone figured out the input spline count for a 42RLE/NP231? I found a well-priced NP231 I want to pick up but it has 21 spline count, not sure of the shaft length yet.