np231 rebuild OOOPS!

OK here’s the short version of what happened....

I rebuilt my np231 with a master rebuild kit from JB Conversions. I have reinstalled it and had a VERY hard time adjusting the linkage, once adjusted it would slip out after 30-50 miles and start grinding.

SO
1. I replaced all bushings and grommets in the linkage

2. Replaced the motor mounts and tranny mount

It was still slipping

Last night I slowly went through the process of adjusting the linkage while the engine was running here’s what I found.

When it shifts to a new position it is not going into gear fully if I move the shift lever on the t-case slightly forward of where it wants be it works but this puts a lot of stress on the linkage and eventually slips back to the place it’s supposed to be. (I hope this makes sense)

What could I have done to modify where the gears meet??? Maybe a bearing not in far enough or in to far?

Any thoughts?

Only way to find out is to open it up again.

I'm not an expert, but from the description, I would guess that the shift sector wasn't seated properly.

You should also make sure the mode fork isn't installed backwards (though I'm not sure you can even close the case if you do that).

The other potential thing to look at would be to make sure that a snap-ring hasn't come loose.

If you can't leave your TC open while you source new parts, have a bastard file ready so that you can file the rough edges off any teeth that got chewed up by the grinding. I apparently misapplied the rearmost snapring in my case, which caused the entire shaft to move forward in the case whenever I hit a large bump or braked heavily. By the time I opened it up, the stop ring had chewed up the synchronizer sleeve enough that they wouldn't mesh any more. You'll still want to replace the parts, but it ought to give you time to find them used cheap, instead of being taken to the cleaners for new.

Did you install a SYE?

Did you need to trim the shift rod to fit back into the case?

I just pulled the t-case and am opening it curently. I do happen to have a second one open already so will scavenge parts from it..


No no SYE or trimming yet

will keep you posted, off to open the case (I am getting good at removing it 1 hour flat with a few breaks) Now if I could just make one work!

Victory!!!!!:sunshine:


The input gear pilot bearing was in the wrong place

wow is it easy to adjust a linkage when the t-case is correct!

thank you all for your help.

Glad you got it fixed..... Any reason to start a new thread on the same issue????

http://www.naxja.org/forum/showthread.php?t=69723

Again, happy to see you got it fixed right, but it would be nice to keep it all together so others can benefit from your experience without having to hunt it down across threads...

Happy wheelin'

This is a good point sorry let me outline my past 2 months of learning and mistakes so its all here.

I bought a 94 xj 4.0 in september I guess. Once I had paid for it and brought it home I found out the t-case was not well because it was makeing horible noises (chain was slipping). I posted for a used t-case and found one local that had a new chain in it for a great price. In my excitment I promptly removed my old case and put this one in. Unfortunatly I neglected to look closly at the differences in the case's and didnt remove the front yoke while the case was on the jeep. I took it to a dealer who promtly took off the yoke for me and only laghed a little bit at my mistake. So I ran home and put the old yoke on the transfer case (which is in my jeep) put on the yoke and connect the linkage and I cannot get it to shift out of 4wd. I needed to be mobile so I pulled my front drive shaft and was mobile but obviously not right. I decide that I will rebuild my transfer case to make it right and order the kit from jb conversions.

I then start the rebuild on the original t-case that came with the jeep. I find that the chain is so loose that it has almost worn a hole in the rear of the case and that the shift fork is worn beyond repair. So I decide to scavange the parts from the t-case I had bought online. I remove the purchased case from my jeep and scavenge the parts from it noticing that this case looks like it had just been rebuilt inside, no metal shavings on the magnet nothing in the filter, perfect bearings...I put the new parts in the case and close it.

I now reinstall the rebuilt t-case and hook it all up again start to connect the linkage and its reversed from the way I remembered it. Pointing down... Hmmmmmmm So I look at the 2 shift levers I have and they are different! one has an angle in one end and the other is straight. At this point I think I had made a $150 ooops and after I stole a look under a random xj I confirmed my susspisions I had use the wrong shift lever when I switched the t-case.

I put the correct lever on and start to adjust the linkage it takes about 3 hours with lots of grinding. This seems wrong to me but also I had no way of knowing what was right at this point.

I finaly get it to shift and the cycle of it working and braking every 30-50 miles begins. every 30-50 miles the linkage would slip and the t-case would slide between gears.

So I replace all the grommets and bushings in the linkage, it dose nothing.

I replace the motor mounts, I am excited about this because I get the old ones out and they are crumbling so it must be the issue!

NOPE!

Now I go back and realy look and the open t-case I have under my work bench . I look at how it is suposed to change gears. It seems that it should be in gear at each stopping point the shift lever hits. So I start my engine and crawl under my jeep and start shifting the jeep by hand listening carefuly to the t-case. It is about 1/4" off of where it should be shifting

I remove the t-case again open it up and start mesuring things. The pilot bearing is not the same as the case I had bought....So I merge the 2 case's again. This time I reinstall the linkage and it takes 2 mins to adjust and all seems perfect.

Thank you all for all of your help, I will not make the same mistakes again just some new ones I am sure.