Originally Posted by Kajun
Thanks .. So how would Do I see if the chain is good? Is it worth opening up or just getting a replacement would be better?
I am actually undergoing the project or rebuilding mine today.
Symptoms: Shifting into 4H results in a whining noise, that gets louder untill it "clunks" and repeats the process. The noise gets faster with speed, and giving the vehicle torque (In 2wd or 4wd) results in a low rattling sound comming from the transfer case (The shifting boot was off, so I could hear everything clearly.)
I am expecting the shifting fork and the chain to be shot. Most rebuild procedures I have looked at result in that, and having to be replaced. The rebuild kits (seals, bearings, silicon, and fork pads) go for between $90 and $250. I found a chain for $60, and a fork for $40. This is probably going to be a two day job. Day one: Removing and disassembling the case, diagnosing issues, ordering parts. Day two: reassembling case, re-installing case, and test driving.
Here is the tutorial I am referencing: NP 231 J Rebuild and SYE install
Also, there are some helpful youtube videos if you search your transfer case type. (Mine is a 231-J)
Compare the time and cash costs of the replacement as opposed to the rebuild, and Good Luck.