salad

So I finally got the proper external lock ring pliers and ripped apart my spare transfer case. It looks like someone's been in here before to do minor work. Reasonable RTV job, oil pickup screen is in brand new condition, magnet only took a little while to clean off, and the pads on both shift forks are in excellent condition. Nothing exciting in the bottom of the case like broken snap rings. Pics are here if interested: http://malcolm.iri5.net/mr_green_jeans/NP231%20rebuild/

However, that looks to be about the extent of what was done. I noticed a pretty strong EP grease stank on every bearing I removed, and nothing around the stupid ^&%@#$!ing internal lock rings was scratched or marred until I got to them (I need to remember to RTV the front output seal).

The outer bearings looked to be in really good shape. Because I'm lazy, I'm going to wager that I can safely skip replacing the needle bearings that the output shafts slide into. Really all I think I need to do in a normal rebuild sense is the large bearings, seals, slingers, clean it up, and SYE it.

What I'd like some advice on is whether this wear is worth doing anything about. I don't really think so, especially for the price of replacement:

Slightly chipped teeth on the front chain drive sprocket:


Same on the mode sleeve:


Also not sure if this is how the teeth normally are on the oil pump:



Now here are the parts that actually concern me. The rear half of the case and the case aluminum range fork appear to have stress fractures. The output housing and the front half of the case look to be totally fine.

Front half of case, note the larger cracks that still hold ATF after a wipe:





Range fork:


Chunks missing:


I assume the rear case half and range fork I should replace. Case half will be a pain to find another. Is the range fork limited to the NP231 only? Any steel versions?

salad

bump

CCKen

Many casting flaws appear to be cracks. Try polishing them out before condemning the case.

I used Dremel polishing bit(s) [kind of a hard rubber material on the end; not a disc, more like an eracer] to blend the chipped teeth in my 242.

I have have seen cast iron range forks for sale on the net. Morris 4X4 I think. You'll need to shop around a bit.

The FSM does alllow blending in certain parts if you are worried about the scratches you made. The only thing that will bite you on the **** is if the surfaces where a seal rides is scratched.

salad

Thanks, I'll give that a shot. The cracks on the rear case half look like heat stress to me, casting defect would make sense.

I shall give them a look

Haha yes, this is exactly it. I had a hell of a time with the lock ring holding the front output bearing in place. Nice gouge in the channel where the seal rides. I used a Scotch Brite pad to take the sharp lip off of it and now it's just a dent. Some RTV should take care of it.

CCKen

Are you talking about a divot in the shaft or on the front case output shaft seal boss - Where the seal seats?

salad

The boss where the seal seats. One of the eleventy billion attempts the blade from a screwdriver took a bite. I ended up using a 1/4" or so, 1/8", needle nose pliers, a small prying tool that I think is for removing nails, and a few R-rated incantations.

CCKen

The boss area shouldn't be too bad.

This is one task where some Voodoo would come in handy. I wonder if Seafoam has a product to make it easier to remove that lock ring....