Hey all. So my dad has a 1997 Chevy Tahoe with the 5.3l V8 engine in it. He is having problems where when he engages and disengages the 4 wheel drive, there is a clunking noise. We looked at it today on the ground and found that if I grab the rear drive shaft and hold it, it doesn't make the clunk noise as loud as it would if I was not holding it. When I held it, I was turning it hard to one side and then the other with the truck on the ground, so the shaft was riding right against the ring gear inside the differential. I tried to wiggle the rear drive shaft at both ends where the u-joints are and there is 0 play in them from both sides of each u-joint (where it goes on the shaft itself and where it mounts to the differential/yoke). I then had my dad engage and disengage the 4 wheel drive and I was holding the front drive shaft and it did not have any clunking noise to it when I was holding it. The only thing I noticed was that the u-joint that connects the front drive shaft to the transfer case was loose a little which I know is bad. Another thing we noticed is that if we back out of the driveway or over anything that has a slight bump in the road, you will hear a clunking noise that is the same tone as the sound we hear when engaging/disengaging 4 wheel drive but not as loud most of the time. That happens once in awhile but seemed to do it a lot more when it was 20 degrees outside. A final note is that we noticed when you get in and out of the truck when its really cold out (30 or less degrees) you hear the same sounding clunk noise once you stand on the running board to get in.
For maintenance, the truck had all the fluids but the transfer case changed at 50k. And every 3k, the oil has been changed. I know the maintenance is bad because the transfer case is never a lifetime fluid and I told my dad that but it was never changed. Does it sound like the transfer case is shot or does it seem like maybe the rear differential is on its way out? I did not get a chance yet to look at the condition of the fluid in the xfer case and differentials but will more than likely check that tomorrow.
Anyone have any pointers for things to check? I don't think the clunk is from the front drive shaft because it has 0 movement when engaging and disengaging. I could see the noise being the front shaft because the u-joint is bad but only when going in and out of gear which it is quiet.
Thanks as always guys!
For maintenance, the truck had all the fluids but the transfer case changed at 50k. And every 3k, the oil has been changed. I know the maintenance is bad because the transfer case is never a lifetime fluid and I told my dad that but it was never changed. Does it sound like the transfer case is shot or does it seem like maybe the rear differential is on its way out? I did not get a chance yet to look at the condition of the fluid in the xfer case and differentials but will more than likely check that tomorrow.
Anyone have any pointers for things to check? I don't think the clunk is from the front drive shaft because it has 0 movement when engaging and disengaging. I could see the noise being the front shaft because the u-joint is bad but only when going in and out of gear which it is quiet.
Thanks as always guys!
