Transfer case nightmares

[RockHopper]

Just rebuilt my transfer case using the trail tough 6.5:1 ratio gears. I was going to do the diff gears instead, but considering the transfer gears cost me a case of beer and 5 free services to a mates car, I thought the price was right.
Anyway, stripped it down and rebuilt it and I even followed the web instructions, put it back in my car and went on my maiden voyage around the block. It drives and shifts fine in 2h,4h and 4l, but it makes a god awful metallic noise under load. Funnily enough, it does the opposite in reverse in that it's fine under load and tends to make the noise when I take my foot off the accelerator. I tend to think it may be one of two things.
1 Maybe I did'nt grind enough off the case and the countershaft is rubbing (although I did grind, check, double and triple check when I put the countershaft in that it wasn't rubbing).
2 Maybe one of the countershaft shims fell out when I reassembled both halves of the case. Is there anyway of knowing?
Does this sound familiar to anyone? I would like your thoughts.
thanx

[nicbeer]

gear noise?

[RockHopper]

No. It's really hard to describe, but it kinda sounds like a high speed tapping noise. The faster you are going, the faster it sounds.

[want33s]

I doubt its a gear rubbing on the case as a hardened steel gear would clearance itself on the soft alloy case pretty quickly.
Sounds more like a collapsed bearing or you forgot/misplaced a shim or thrust washer.

Jas.

[mrw82]

did you shim the input and output shafts correctly? there might be excessive endfloat in the shafts (which would explain the difference between forward and reverse)

when I done my case I had to put 0.040" shims in one shaft and 0.020"shims in the other!!! (for those that dont know 0.040"=1mm and 0.020"=0.5mm) Quite a lot!!!

[RockHopper]

I think I may have found the problem. After writing the original post I went back out and pulled the rear tailshaft off the car. I started the engine and put it in 2nd and the noise was there. I got under the car and listened and it sounded like the noise was external and not internal and from the front of the box. Anyway, after switching the car off I rotated the input shaft by hand and I could feel at a certain point in it's rotation an ever so slight grind. Upon closer inspection with a torch I found that the metal seal dust cover on the input flange had somehow become slightly dented (probably when I removed it). I put a thin screwdriver in under the dust cover and bent it back out a little. Started the car, put it in 2nd and the noise had gone.
I put the tailshaft back in and took it for a drive. The noise was still there, but nowhere near as bad. Decided to go for a round 40km trip on the freeway. Returned home and the noise was still there. Plan was tomorrow to remove the front output flange and swap it over with the input flange, but when I went out for pizza tonight, the noise had mysteriously disappeared.
I guess I'll just see how it goes tomorrow. If the noise returns I'll swap the flanges over.

[lump_a_charcoal]

Phuck yeah, pizza rules.