Intermittent grinding/rubbing noise:

[SLO C5]

If I am at a stop sign(or moving slowly) and turn the wheel left and accelerate I get this loud noise. It does not happen when going right. It seems to be coming from the front of the car, driver's side. If I am doing this over a bumpy road the noise seems to change volume with the suspension oscillations(for 1 or 2 seconds). It's only at low speeds. It really sounds like tires rubbing, but I know this is not happening since it occurs even when the suspension is not compressed at all. Clearance is not an issue, my Sub has a 10" suspension lift, 2" body lift, and 39.5" swampers.

This morning on my way to work it was doing it when applying the brakes at a very low speed. And when in gear with the brakes applied(and car stopped), the noise was audible as well.

After driving for a while on the freeway, then back in areas where there were turns and stops the noise went away.

From the noise this morning it seems brake related, but usually I first noticed it while accelerating. Could it be something with the master cylinder/vacuum system?

Also, the brake pedal seems to make a lot of noise when I press on it. It almost sounds like air rushing out of tires, just not as loud.

 

[4X4HIGH]

I would pull your locking hubs off and check in there. I had a similar noise and it turned out that my passenger side hub was having an issue.

 

[SLO C5]

Anyone else?

 

[Chaddy]

I had a similar sound and it was my rotor dust cover bent and rubbing on the rotor.

I accidentally bent it instaling my brakes.

 

[jonrpick]

If I am at a stop sign(or moving slowly) and turn the wheel left and accelerate I get this loud noise. It does not happen when going right. It seems to be coming from the front of the car, driver's side. If I am doing this over a bumpy road the noise seems to change volume with the suspension oscillations(for 1 or 2 seconds). It's only at low speeds. It really sounds like tires rubbing, but I know this is not happening since it occurs even when the suspension is not compressed at all. Clearance is not an issue, my Sub has a 10" suspension lift, 2" body lift, and 39.5" swampers.

This morning on my way to work it was doing it when applying the brakes at a very low speed. And when in gear with the brakes applied(and car stopped), the noise was audible as well.

After driving for a while on the freeway, then back in areas where there were turns and stops the noise went away.

From the noise this morning it seems brake related, but usually I first noticed it while accelerating. Could it be something with the master cylinder/vacuum system?

Also, the brake pedal seems to make a lot of noise when I press on it. It almost sounds like air rushing out of tires, just not as loud.

I'd check the front hubs too. Factory auto-locking or manual hubs?? My autos went South and made all kinds of racket before I put the manuals on there.

 

[SLO C5]

The hubs are manual.

Update:

This morning I drove it to work. The first couple of stop signs the engine was still warming up and the idle was around 1K RPMs. When applying the brakes the noise could be heard when going under 3mph and even louder when completely stopped. Then I made a left turn from a stopsign, and right after the stopsign there is a pretty good sized gutter. When accelerating from the stopsign and turning left the noise could he heard, and then it was made louder for the 1/2 second that the suspension was reacting from the bump. After that, I didn't hear it for the next 45 minutes, 30 of which were a highway cruise. Once back into my work area there were stoplights, with turns, etc.. but not a peep. It definitely is coming from the front leftside of the car.

 

[Leper]

Need info on your vehicle.

 

[SLO C5]

Need info on your vehicle.

It's definitely something in the front axle area, so I'll describe that as best I can(I'm a noob and bought the Sub a month ago as it is).

89 Suburban 1500
All drivetrain was replaced by previous owner 1 year ago
D44 8 lug with flat top knuckles
Spicer manual hubs
4.88s
crossover steering
13" discs up front from a military truck
39.5x15.5x16.5 Swamper TSLs
10" lift Superlift springs

 

[SLO C5]

Update:

We got some rain last night so I went out and played around in the mud. Good times.

I was in 2WD for the first areas muddy fields I went through. Got mud all over my Sub, what fun!

As I was kicking the tail around a bit, with the wheels pointing left, I could hear the grind/rub over most bumps I encountered. When doing the same thing going and the wheels going right, I could hear the noise over bumps, but it wasn't nearly as loud.

Then I went over to a bumpier area to play. I put it in 4HI, and locked the hubs. When going over any bumps, the noise was pretty damn loud. Louder than it's ever been before. When I got off the mud/dirt area and onto the paved roads, the noise was extremely loud when accelerating from a stop. I pulled over to put it back into 2WD, and unlock the hubs, and I could not get them in the free position at all. The noise was still there as I drove another couple 100 yards. I pulled over again to try and unlock, and it put them back in the free position without any trouble.

I then proceeded to drive home and didn't hear a sound at all. I'm stumped.

Should I replace the hubs? If I take it apart, is there a way to tell they are bad? And if I do try new ones, what's the best place to get some for a 8 lug 3/4 ton D44? They are Spicer hubs.

Quick Q: As long as I am not moving(duh) it shouldn't matter if I'm in P or N when trying to unlock the hubs, right?

 

[4X4HIGH]

I would pull your locking hubs off and check in there. I had a similar noise and it turned out that my passenger side hub was having an issue.

I told you that you should check the locking hubs.

 

[Dabba]

im no expert but thats a big indication it could be the hubs

 

[Blue85]

The hubs are manual.

When applying the brakes the noise could be heard when going under 3mph and even louder when completely stopped.

This is the part that confuses me. If you hear the noise when the vehicle isn't moving, then it is the engine, one of the accessories or the very front-most parts of the transmission.

 

[SLO C5]

I might try and take the hubs apart tonight and check them out.

If there is something wrong, would it be pretty clear? I'm not exactly sure what to look for.

UPDATE:
I tried putting locking/unlocking the hubs a few times yesterday, and I even put it in 4WD for a bit. I took a few runs through some mud as well(not in 4WD), the same ones that usually cause the sound to be really loud. I couldn't get a peep out of it. Not a sound. Weird

 

[SLO C5]

This is the part that confuses me. If you hear the noise when the vehicle isn't moving, then it is the engine, one of the accessories or the very front-most parts of the transmission.

I think this is a separate noise that only occurs when the engine is still warming up and idiling right at or a little over 1K RPMs. Disregard this issue for now.

I appreciate all the advice so far!