My early bird 99 has 241,000 miles on her, and I have been pulling my cargo trailer for side work a lot more then normal lately. I get a gritty grinding noise when I turn left of right at slow speeds. I have read on here before that the limited slip is probably worn and thats what is making the noise. It makes no noise with out the trailer. Is this something to worry about? I change the fluid regularly and make sure I add the limited slip additive. How long do the bearings and that stuff last. I am just not wanting to blow up my rear end away from home pulling something. Or is that grinding noise the beginning of problems?

 

Aside from the so-so factory limited slip, the Sterling 10.5 rear axle is a pretty stout unit. Don't get me wrong, you'll find an occasional failure, but for the most part these differentials give trouble-free service.

Having said that, why is yours making a grinding noise when you tow?

Are you sure it is the rear end? How much does your truck squat when you have the trailer on the hitch? Could the grinding noise be coming from the slip joint or carrier bearing?

 

That seems odd. How much is this trailer? I'm with Redford's idea that the squat of the truck might be related. What if you load the bed of the truck with a good sized load? Does it make noise then?

If you have a center support bearing, I would look closely at that, followed by the rearmost U-joint. Those items will be most affected by changes in driveline angle.

Also, are you sure it is not a trailer bearing or brake?

 

It's kinda weird because my 97 F-150 did the same thing when pulling a trailer or heavily loaded. Mine truck does do it if I have a bunch of weight in the bed also. My truck does squat at all, I have airbags to bring the truck back to level. My trailer right now is about 1" lower in the front then the back. It is almost level. Drive shaft was rebuilt two years ago and I grease the u joints regularly. I don't think it is anything to do with the trailer since the truck will do the same thing if a heavy load in the bed. The trailer is a 7x16 cargo trailer with all my tools for construction in it. I should get an exact weight but I am guessing 7 to 8 thousand pounds maybe. The weird thing was it was raining last night and it seemed to be more noticeable then.

 

None, I have a set of airbags that I always bring the truck to level, without the air bags it probably squats an inch.

 

It is kind of a long shot, but have you checked your rear brakes? Are your pads in decent shape?

 

Pads are good. This has done this ever since I bought the truck at 167,000 miles.

 

OK, so the scenario is as follows:

1. Your truck acts normal until you hitch up a trailer.
2. You hear a grinding noise with the trailer hitched up, turning left or right at low speed.
3. This noise has been present since you've had the truck.
4. The rain might make this worse.
5. You also hear this when you're hauling a heavy load in the bed, so it isn't trailer related.
6. You have air bags, which eliminates any suspension squat from the load or tongue weight.

So, would I be correct in saying that you hear this grinding noise when turning left or right when you use your air bags to level your load?

 

I think that is correct, the only thing is I would have to try pulling the trailer without the bags to give a total yes. When I do run the bags I only run 30 psi which isn't much if you ask me, my dad runs 80 when pulling his trailer.

 

im going to say its the anti squeak pads on the rear leaf springs, i dont tow or haul ever day maybe once a month. my pads wore out at like 70k, they wore down to nothing and my leafs were rubbing against themselves squeaking like crazy. went to a spring shop and bought new anti squeak pads and it solved my problem

 

I will take a look at that. It's more of a gritty sand/grinding feel though. Will look thou.

Thx for the suggestion.