HunterDude89
NAXJA Forum User
- Location
- Los Angeles, CA
So I just did a full rebuild and SYE install on my NP231 transfer case. I actually got a whole new (used) transfer case and used it for the case mostly. My original one blew up, blowing the case apart.
So I got another NP231J (a 23 spline the same as my original) and used the case, chain, and the steel range shift fork from it. All the bearings and seals were replaced, and I reused my original planetary gears, range and mode gears (on the new SYE shaft), oil pump, and front output shaft.
I took my time rebuilding it to make sure I did it right, but now that I've got it back in the truck and driving I noticed its pretty noisy. I know it is the transfer case because you can hear it even when the transmission and transfer case are both in neutral...
I did notice some differences between the two transfer cases when I took them apart. My donor transfer case had a synchro on the drive sprocket and my original did not. My donor also had a steel range fork and my original had an aluminum one. Lastly, my donor had a longer rod that the shift forks slid onto than my original (I used my original rod and mode shift fork and gear).
The only things that concerned me during the rebuild was using the steel shift fork (I did this because the pads on my original aluminum one were worn out and I didn't have time to order a new one), and that my chain seemed to sit slightly crooked. I didn't think much of it at the time because I thought I remembered and saw it that way when watching rebuild videos and when disassembling the donor case earlier. The main shaft sat in great and everything fit, same with the front output shaft. When the chain was in the chain sat about halfway into the case on the main shaft side, and level with the edge of the case on the front output shaft side. Is this normal? Could it be the cause of my noise? It spun fine once fully assembled on the bench and when in the truck, and it drives great no weird vibrations or binding or clicking. Just a kind of whining noise, or very slight metal rubbing. I just figured everything would line up a little better once I tightened the front output yoke down. And that if all the snap rings and everything fit right once I got the other half of the case on it was just fine (and everything did go back together fine).
The only other issue I had when doing this project was getting my rear driveshaft to fit. It is a CV driveshaft with a slip and at first it wouldn't extend long enough to reach, so I pulled on it and got all the bolts in a few threads and then slowly tightened each one down evenly until it fit perfectly. I just figured it didn't want to extend fully because it is older and hasn't moved much from its old, shorter, position (my original transfer case had a hack and tap SYE on it, as my new one is a full replacement kit).
I'm just hoping that someone has run into a similar problem or has more experience with this and could help me out. I was thinking maybe all the parts need to wear in with each other or maybe I missed something that was right in front of me. Any input is definitely appreciated! :doh:
So I got another NP231J (a 23 spline the same as my original) and used the case, chain, and the steel range shift fork from it. All the bearings and seals were replaced, and I reused my original planetary gears, range and mode gears (on the new SYE shaft), oil pump, and front output shaft.
I took my time rebuilding it to make sure I did it right, but now that I've got it back in the truck and driving I noticed its pretty noisy. I know it is the transfer case because you can hear it even when the transmission and transfer case are both in neutral...
I did notice some differences between the two transfer cases when I took them apart. My donor transfer case had a synchro on the drive sprocket and my original did not. My donor also had a steel range fork and my original had an aluminum one. Lastly, my donor had a longer rod that the shift forks slid onto than my original (I used my original rod and mode shift fork and gear).
The only things that concerned me during the rebuild was using the steel shift fork (I did this because the pads on my original aluminum one were worn out and I didn't have time to order a new one), and that my chain seemed to sit slightly crooked. I didn't think much of it at the time because I thought I remembered and saw it that way when watching rebuild videos and when disassembling the donor case earlier. The main shaft sat in great and everything fit, same with the front output shaft. When the chain was in the chain sat about halfway into the case on the main shaft side, and level with the edge of the case on the front output shaft side. Is this normal? Could it be the cause of my noise? It spun fine once fully assembled on the bench and when in the truck, and it drives great no weird vibrations or binding or clicking. Just a kind of whining noise, or very slight metal rubbing. I just figured everything would line up a little better once I tightened the front output yoke down. And that if all the snap rings and everything fit right once I got the other half of the case on it was just fine (and everything did go back together fine).
The only other issue I had when doing this project was getting my rear driveshaft to fit. It is a CV driveshaft with a slip and at first it wouldn't extend long enough to reach, so I pulled on it and got all the bolts in a few threads and then slowly tightened each one down evenly until it fit perfectly. I just figured it didn't want to extend fully because it is older and hasn't moved much from its old, shorter, position (my original transfer case had a hack and tap SYE on it, as my new one is a full replacement kit).
I'm just hoping that someone has run into a similar problem or has more experience with this and could help me out. I was thinking maybe all the parts need to wear in with each other or maybe I missed something that was right in front of me. Any input is definitely appreciated! :doh:
