I'm not sure how this can be related, but recently had new brakes lines on my '91 4wd pickup. since getting it back, i notice a strange noise as i coast to a stop. the other day, i was sitting still, accelerated, never switched gears to 2nd because i was only moving a short distance. as i let the transmission slow the rig down, i noticed this grinding sound. once i pressed the clutch, it went away. so, i set out to duplicate the problem to try and get a better idea of where the sound was coming from. i am able to duplicate the sound under the circumstances everytime. naturally, i know that if i engage the clutch, i won't hear the noise, but that's not really resolving anything. the noise sort of sound as if i am trying to engage the 4wd while in motion. any suggestions?

 

Sounds like the input bearing in the trans is going. If that is it it will get worse and worse then it will start to pop out of gear and will get louder and louder. This happend to me twice.
It could just be a u-joint but they usually don't make much sound when they go.

 

what's involved in that repair?

 

To change the input bearing is not to bad. You have to pull the tranny and pull the bearing out. The trans has to be disasembled a bit to do that. I just ran mine until they crapped out then got a used tranny for $150 and through that in. It will cost you more to fix that tranny.
Depending how mechanical you are you should take it to a tranny place and let them take it for a drive and see what the exact problem is.

 

cool. thanks. off to the tranny place.
thanks again.