I have a '95 4x4 5sp, on the way home last night im just cruising in 5th under a little acceleration, and at around 1600-1800 rpm, theres an awful gear-grinding sound, just for a split second. so i pull it out of gear, and the same thing happens in 3rd, and 4th...just for a second theres a very loud grind. the trans is still pulling in all 5 gears, and it shifts smooth. Im guessing its in the rear end. but the fluid level was good, i pulled the cover and there were no obvious signs like broken teeth, shavings etc. but im not sure what else to look for. Im was supposed to head to the lake tomarrow w/ the family, pulling a 20 ft boat, but i guess thats not gonna happen if i dont figure something out here Any suggestions? Thanks.

 

Got a bad U joint? I've had some make some "interesting" noises before.

How is the oil in the rear? Was it full and new looking or was it burnt?

I'd bet on the U-joints.

Ed

 

Im pretty sure the U joints are good, but the oil was a little burnt looking, but could this cause noises like that?

 

What about the transfer case? Sounds like you've eliminated the tranny and diff.
However, if it always happens at a certain RPM no matter what gear you're in then it might be engine related.

 

There are two other items to check, the first being the clutch throwout bearing, and the second being the pilot bearing.

To check the throwout bearing, lightly push the clutch in any gear and listen for a change in noise such as grinding or rapid clicking.

To check the pilot bearing, hold the clutch in while the transmission is in gear and you are stopped. If you get a squeal or grinding, then you have found the culprit.

If those are not the source, check you universal joints by jacking up first one end and then the other. Roll the drivelines and listen for cracking, and then rock the drivelines and look at each universal joint for slop. Do the same thing on the front axle, and check the trunions that allow the front axles to turn with the wheels when you steer.

If none of those, then back to the transmission. It is possible to have the 5th gear shaft nut work loose enough to allow the short 5th gear shaft to make grinding noises as it tries to loose the driver off the half spline. Rarely does it make noise and still work, but I have seen it happen.

To check the nut it is necessary to pull the transfer case and the tailhousing off the transmission to gain access to the nut and shaft. If it is loose, do not screw around with the cheapo locking nut fixes, they never work very long if you pull much of a load, but go for a new fully splined shaft and locking nut.

 

let me guess wen u give it fuel grinding noise wen you take foot off no noise

if thats the case U JOINT if its not do wat rcw says im to laysy to tip all that