Rebuilding the NV231J transfer case
- Thread starter RaymondT
- Start date
OP
I decided to rebuild mine when I installed a new AX5 transmission. I bought the rebuild kit with new chain from Novak Adapters. The only reason I did it was because of the bearing noise I could hear. Even with the transfer case in neutral and idling in all 5 forward gears you can hear the sound of the input shaft spinning. The higher the gear, the more pronounced the bearing noise. No banging or clicking, just rotational gear noise. Could also be the old/new transmission making the noise. The thin fluids in both these units don't do a good job of dampening noise. So when I took the NV231J apart, everything inside was pristine. No wear to speak of, no filings, etc. When you consider this transfer case is tough enough for a V8, what's my little 4-banger going to do to it? Especially when mine was never off-roaded. So when it was all said and done, the noise is still there. I'm now thinking it's quite normal. There's no floor insulation and the noise is only noticeable when the oil is hot and you've got your foot into it on a hill or on deceleration. If you drive with a soft-top or the windows down, chances are you don't even hear it.
I'm going to toss some 30W into the NV231J just to experiment. Novak literature does mention that this helps quiet these down.
I'm going to toss some 30W into the NV231J just to experiment. Novak literature does mention that this helps quiet these down.
Great thread, post some photos (if possible) as you go through the process.
This is one of those things I think a lot of people overlook (rebuilding the transfer case). Mine may be due for it as well!
This is one of those things I think a lot of people overlook (rebuilding the transfer case). Mine may be due for it as well!
I have done a few years ago. They aren't all that bad actually. A couple I did had cage less needle bearings which were a pita to keep in place and lined up when sliding in the shafts. I also remember some having a one piece case which made bearing removal and install a bit tricky. Other than that, pretty straightforward and not a ton of parts to deal with.
OP
Way easier than a transmission.
About the only tricky thing in the process is removal of the pocket bearing for the rear of fwd driveshaft output gear. You can a) take the case half to a dealer or gear shop, b) remove it if you have access to the right type of puller with the slide weight and proper sized fingers, or c) like I did - pry out the inner cage, shake the rollers out, and use a dremel to (carefully!!!) cut through the outer shell and pry it out once it's stress relieved. The wife bought me a cordless dremel years ago and it's save my ass on so many jobs I can't count. The little fragile cut wheels are useless - you have to buy the re-inforced versions, about 1-1/4" dia. I use a half wore one to get into the tight areas. Obviously, you can't cut straight up and down in the pocket, but you do it at angle. Do it carefully and work the sharp edge with a small screw driver. In the end it was only 15 minutes or so and minimal tooling marks which were just superficial. Rent/buy/borrow a set of seal/bearing installers. I paid only $45 on Amazon and that was the Canadian site. U.S. even cheaper.
Novak Adapters carries the rebuild kits for different years along with a new USA built chain.
About the only tricky thing in the process is removal of the pocket bearing for the rear of fwd driveshaft output gear. You can a) take the case half to a dealer or gear shop, b) remove it if you have access to the right type of puller with the slide weight and proper sized fingers, or c) like I did - pry out the inner cage, shake the rollers out, and use a dremel to (carefully!!!) cut through the outer shell and pry it out once it's stress relieved. The wife bought me a cordless dremel years ago and it's save my ass on so many jobs I can't count. The little fragile cut wheels are useless - you have to buy the re-inforced versions, about 1-1/4" dia. I use a half wore one to get into the tight areas. Obviously, you can't cut straight up and down in the pocket, but you do it at angle. Do it carefully and work the sharp edge with a small screw driver. In the end it was only 15 minutes or so and minimal tooling marks which were just superficial. Rent/buy/borrow a set of seal/bearing installers. I paid only $45 on Amazon and that was the Canadian site. U.S. even cheaper.
Novak Adapters carries the rebuild kits for different years along with a new USA built chain.