Hello all,

I have a 2003 Sport Trac 4wd with 299,000 miles.

There is what sounds like wheel bearing noise (grinding) that was noticed after returning from a trip where I flat towed it behind my rv. I did not notice the noise the last time I drove it - before towing it about 450 miles. I have towed this vehicle for many years and miles this way - transmission and transfer case in neutral with key in on position to unlock steering. I stated this part about the towing because the noise may have gone unnoticed for many miles.

About 20,000 miles ago, I changed front wheel bearings, brake calipers, upper and lower ball joints, shocks and outer tie rod ends. Also rear brake pads.

I put the vehicle on jack stands and in drive mode couldn't hear anything in either 2wd or 4wd. I held one wheel at a time so the other side would spin. After checking for wobbling wheel bearings, I took off the wheels and did a push / pull on everything - all seems good. I changed driver's side wheel bearing anyway because I thought it to be a little rough. I removed the front drive shaft and took it out on the road. Noise was still there. This makes me think front differential but before entering unknown territory (for me) is there something else I can do to narrow down the problem? At this point, I'm not even convinced it is from the front end - maybe the sound is radiating through the truck.

 

If you can find someone with a ChassisEar (and preferably the wireless version) that could help you track down the noise. The ChassisEar is a system of multiple microphones on clips that get placed in the areas the noise may be coming from. The microphones are connected to a switch box with headphones (or speaker). Switch between microphones to see where the noise is loudest, then move the other microphones near where it's loud until the noise can basically be pinpointed.

I used mine to confirm a clunking noise in a co-worker's Explorer transfer case. It worked well but did require a few trips around the block.

-Rod

 

Thanks for the idea. I don't know anyone that has one of those tools and I was trying to avoid paying someone for a diagnosis.

Is there a way to drive without the front axles? I have read that the spindle keeps the wheel bearing in place.

 

Well I tore down the front axles and reinstalled just the stub that goes through the wheel hub effectively disconnecting the differential. Grinding noise still remains! Now I'm leaning toward the transfer case. I just remembered that last winter once in awhile it wouldn't shift from 4wd to 2wd without shifting into reverse for a few feet. Maybe this is related?