NP 231

[Frank]

A friend had a T-case that was cracked almost in half. Removed it, and he had gotten a replacement. Wouldnt slide on. Found the spline was for a smaller shaft. Split both cases,removed the Planetary from the blown case and installed it in the one that wouldnt fit. Did I do good or should I tell him not to install it. Is there anything else I should have checked before I tell him to install it. Is there anything to adjust or is it okay . Thanks FjR68

[Kurt]

Issue is usually a 21 spline vs a 23 spline tcase input shaft

Is is OK, Depends...

What where the year, Model & tranny of the two tcase's?

Nothing to adjust

[Frank]

I dont know what the replacement came out of. I thought the difference was 4cyl Vs. 6. I will see him today , Thanks Kurt FjR68

[mrfreakinwhite]

I dont know what the replacement came out of. I thought the difference was 4cyl Vs. 6. I will see him today , Thanks Kurt FjR68

21 spline vs 23 spline. With the introduction of the HO motors, they increased the splines from 21 to 23, circa 1991. At least on Cherokees.

[Frank]

Its on a wrangler , not sure of the year. At speed he hit a tree with the left front tire and fender. Tore the leaf spring off and the drive shaft ran into the case------ I assume. The seller told him it came from a wrangler, He went on his word. FjR68

[nostaw]

Poking around, this is probably the best summary I found on what to look for:

The easiest way that we have found to identify the proper transfer case input is by identifying the stock transmission that Jeep used. The 21 and 23 spline output shafts vary on different transmission models. The AX15 transmission is always 23 spline and protrudes 1/2" beyond the face of the transmission. The Torqueflite and NV3550 are normally a flush 23 spline. The AX4 & AX5 always have 21 splines and is flush with the back of the transmission adapter until 1996; and then in 1997, the AX5 output shaft was lengthened to a 1/2” stickout past the tailhousing adapter. The Peugeot transmission is always 21 splines and protrudes 1/2" beyond the back of the transmission adapter housing. We have seen the AW4 automatic transmission in both a long 21 & 23 spline.

Probably won't help your friend if they don't know where it came from. If the parts you swapped didn't look damaged you're probably OK. Only way to know is to run it and see if it falls apart.

JW

[Frank]

The internals looked undamaged. The planetary rotated without bind. The case shattered and I assume it was the drive shaft. Bolted in fine. He cut off the skid pan bolts and is working around that repair. He bought the wrangler for 300.00 as is. It seams to run well, no smoke,tranny shifts smooth. I think he got a great deal. Thanks for the input . FjR68

[Frank]

Update : He moved the Jeep and when he shifted the T-Case he lost everything,drive wise. Like its in neutral. What did I do wrong ? Its got to be something with the shift detentes , right. Where should I have set it ? I dont have a book on this T-case. FjR68

[nostaw]

It is probably to do with the adjustment of the linkage... Did you guys readjust the linkage after you installed it?

Procedure is to disconnect the linkage, put the t-case in 4-lo by hand, have someone in the Jeep hold the shift lever in the 4-lo position, then tighten the linkage again underneath.

JW

[Frank]

I just put it together. When it came apart I heard it snap once so when I put it together I moved the cam one click. I guess I will take it apart again and see where the shift detent thingy is. I didnt adjust or move the shift rod so I didnt think to do anything with it. Thanks Jon. Fjr68

[nostaw]

The linkage is external to the t-case.

[Kurt]

Could be that the shift detent spring an/or ball may not be where they belong.
Also you need to be careful to install the "mode" sleeve and hub correctly. It's easy to install it backwards.

With the linkage disconnected you ought to be able to shift it thru the 4 positions. Each time the shift lever should click into one of the 4 positions.

If you drop the tcase you ought to check the operation on the bench and shift it thru all 4 modes and verify it's working OK before bolting it back in.

[Frank]

I feel it has to do with that stepped lever as I didnt know where it was when it came apart . I thought I heard it shift at least once pulling the halfs apart. Im getting a book today. I should be able to move the shift gizmo and find all 4 ranges from the outside ? If I cant I will pull it apart again. Thanks FjR68

[mrfreakinwhite]

Yes, the lever should be able to be operated from underneath.

[Kurt]

Yes, the lever should be able to be operated from underneath.

Agreed

You may need to use a pair of channel locks or something to move the lever. The spring for the detent can make it a bit hard to move. Sometimes I use a pair of channel locks on it for a bit more leverage. You may also have to spin the output shaft(s) so the teeth mesh while shifting it.