GM-GMC: 1987 chevy pickup 4x4, exhaust issues, chevy pickup

Question
QUESTION: I just bought a 1987 chevy s-10 (title says s-14??) it has 120,000 miles.  All of a sudden while on the freeway it makes this awful grinding noise! It seems to be trans issues but this noise will come and go in any gear at any speed. it kind of sounds like the starter is engaging. a friend says he thinks it is in the transfer case. The sound seems to stop on its own, briefly then go again. putting the truck in neutral does'nt seem to make it stop.  I was hoping to get a good work truck but now i'm worried its more trouble than its worth.  any info would be greatly appreciated.    thanks

ANSWER: Matt ,


When you are driving , do you put it in Neutral , then ?

It could be many things :

Wheels bearings

Drive Shaft issues

The transfer case you can tell if they are bad. Turn a corner and see if the front wheels grab with the 4x4 OFF ... If they do then you have issues with 4x4 transfer case

At a low speed 20-30 mph . on a road with NO CARS . try to steer back and forth , with the steering wheel FAST >>> listen close  do you hear the noise come and go ?


Exhaust issues ?

Do you feel any vibration threw the floor board at all ?


Let me know !


Dave G.

---------- FOLLOW-UP ----------

QUESTION: HEY MAN I APPRECIATE THE RESPONSE! Well, it does it at extremely low speeds (barley idle)  as well as high.  when in 4 wheel drive the noise still comes but much higher pitch. it really sounds like a trans thing but the next second its driving and shifting fine.  it loses the pull when the noise kicks in. and it is leaking trans fluid at a good rate. i know nothing about transmissions at all!! i really don't want  to spend wayyyyyyy more than i need to simply because of my ignorance. i truly appreciate your time. thanks again.

Answer
Hey Matt ,

When you say It loses its pull? What do you mean .

Transleaks : 90% of them coem from the rear seal or the main seal . You have  to remove the drive shaft then pull out the old seal and tap in a new one with a brass hammer !. That would probably stop your leak . A $10.00 part . You can also try a can of STOP LEAK . From auto parts store ... If you are loosing that much .maybe the clutch plates are not being lubricated enough . this would make noise as well . Heat does amazing things . Maybe the fluid in the beginning is low . No lubrication on your parts up higher in the trans. Then when you start driving it is noisy then fluid starts getting onto the plates and then the trans shifts good. Then you let it sit over night or for a few hours and the same thing again ., Does this sound right ?

Let me know !!!


Dave G