bday

I have a 1986 pickup with a new 22re, a seemingly good trans and 4 wheel drive. Manual hubs. However, there have been two instances where I am driving in 4hi (once) straight and (once) on a slight curve in third gear (maybe coincidence) under minimal stress and I hear a sound like grinding gears. The sound is unaffected by depressing the clutch or shifting into neutral. It is loud enough that I can hear it over my stereo. Sounds like a buzz saw. Like gears slipping in the front (my best guess is passenger side). It last for 3 or 4 seconds and goes away. Both times I had been driving in 4 wheel for at least 15 miles and on a slippery surface. I have not noticed any other noise or problems with 4 wheel other than these seemingly random occurrences. Has anyone had a similar issue? or any ideas?

millball

May be that one of your locking hubs is coming unlocked because of wear, damage, or incorrect assembly and you hear the splines in the hub working against each other when this occurs.
I'd inspect the hub on the side that the noise appears to come from.
Do you have Aisin factory hubs or some sort of aftermarket brand??

bday

Thanks for the post millball. GOnna have to take a hard look and get an answer for ya. Guessing they're stock. Red locker. Just picked this thing up. I'll take some photos and post. Weekend starts tomorrow so hopefully get the thing apart.

RJR

Red sounds like an OEM Aisin hub. Could be simply that the lube is so old and stiff inside that the locking collar doesn't slide into full engagement. It's a fairly easy weekend project to disassemble, clean, and relube them, and would be worth doing if you just got the truck and don't know the history. Here's a good writeup on how to do it. https://www.yotatech.com/forums/f116...ild-up-158644/