Yeah I would its out do it now and change the t case fluid also

 

Just ordered a t-case saver from ebay, 47.90 shipped.

 

does this stop that clunk going into gear? mine clunks especially when parked on an incline then putting it in gear.

 

The clunk is going into reverse

 

For follow-up:

The Gillys transfercase saver came in the mail yesterday and I installed it this afternoon. It was as easy and painless and everyone had said it was. I undid the rear driveshaft U-joint straps, pulled the driveshaft out, and removed the transfercase tail housing. The tail housing required a few light taps with a rubber mallet to come loose after pulling the bolts, but it did and came right off. I had a large snap ring plier thingy (sorry for being too technical) so I removed the snap ring (which was still in place just fine) and installed the Gilly's thing with the supplied red lock-tite. I lost maybe two tablespoons of transfercase fluid during the whole process. It was not a messy procedure. I did jack the back of the truck up a little bit just to give me more room underneath. I used some black permatex gasket maker stuff putting it back together and ta-da - I was done.

Well almost. Between all that I decided since I had the driveshaft out I would replace the rear U-joint; the factory one that has been in there since 1996. It was a major PIA getting it out (using a Harbor Freight tool) but eventually I got it out and a new one in. If I had a press I'm sure it would not have been such an issue, but that U-joint did not want to budge.

So I am pleased with this whole process, and now I have peace-of-mind for now having to worry about that snap-ring causing a problem.