Rear wheel grind that I cannot solve

[Iflyasa]

So here's the deal. My left rear wheel is grinding. It only happens under load, going up a steep hill, or with 3 passengers giving it power.

I have disk brakes. I took the disk hub off. The hub spline grooves look normal. I pulled the axle out. The axle grooves look "ok".

They are not sharp and crisp but appear ok I guess. I replaced the axle bearing. I put it all back together. Everything is secure and tight. It STILL makes a grinding noise under load. Almost like Jake brakes on a big truck.

It's not the differential. It's only the left rear. Coukd the axle be spinning on the disk hub? That's the only thing left. I may find another axle in the morning. Do these axles where out like that?

[JohnnieB]

Originally Posted by Iflyasa

So here's the deal. My left rear wheel is grinding. It only happens under load, going up a steep hill, or with 3 passengers giving it power.

I have disk brakes. I took the disk hub off. The hub spline grooves look normal. I pulled the axle out. The axle grooves look "ok".

They are not sharp and crisp but appear ok I guess. I replaced the axle bearing. I put it all back together. Everything is secure and tight. It STILL makes a grinding noise under load. Almost like Jake brakes on a big truck.

It's not the differential. It's only the left rear. Coukd the axle be spinning on the disk hub? That's the only thing left. I may find another axle in the morning. Do these axles where out like that?

Yes, it could be. The spline coupling between the axle and the hub is the same for both disk brake nubs and brake shoe type hubs. (Granted, the aftermarket disk brake hubs are better quality than the OEM hubs.)

Since it only grinds when heavily loaded, try scribing a line on the hub that lines up with the cotter pin through the castle nut and axle. Take a drive that produces the grinding sounds, stop and check if the scribed line still lines up with the cotter pin.

Also, there are splines on both ends of the axle and sound travels through solid metal very well, so slipping splines at the differential gear cluster end could sound like it was coming for the hub end.

I've got a clunking sound I haven't been able to locate yet and after replacing the likely suspects, I've decided to let it go until something breaks, so I can find and fix it.

Originally Posted by JohnnieB

I've got a clunking sound I haven't been able to locate yet and after replacing the likely suspects, I've decided to let it go until something breaks, so I can find and fix it.

have you tried driving with out your tin foil hat on ?

[JohnnieB]

Originally Posted by crash test dummy

have you tried driving with out your tin foil hat on ?

Yep.

[Iflyasa]

So I believe I figured it out. I replaced the rear axle bearing. No change. The axle grooves on the spline looked OK. The disk hub looked new. So there is no way the axle was spinning. I know the hubs will fail before the axle. To prove my theory. I held the brakes and gave it power. There was no sound or anything. So there was no spinning uhder a heavy load around 1 mph.

So I had noticed my brake cable had a bad wear spot. I could actually see the metal showing. It only made a grinding noise under heavy load while driving, or with 1 passenger on the rear.

I realized under those conditions, the rear end would sag temporarily. What was happening was the rear would sag, the brake cable would rub the knobbies on the tires making the grinding noise. Take the power away, the back doesn't sag, and no noise.

So the main grinding noise is gone, but there is still a lightly noise only on the left, and not the right. I'm still working on that issue.

[scottyb]

Thanks for letting us know!