I have a 2001 Supercrew and have a weird rumbling noise when I start accelerating from a stop into a turn. It almost sounds like the tires don't have any traction and are "skipping". I only hear it at VERY low speeds (as I said startying from a stop)

After replacing the tires there was no difference. The alignment was checked and was fine. Any ideas

 

It appears that no one had any ideas or didn't want to help so I figured it out myself. Apparently the shuddering noise was from the limited slip. I had the fluid changed a while ago and apparently no friction modifier was added.

 

jpopvriens-

Did you add the friction modifier to your rear pumpkin yourself? If so what was the brand you used.

I recently had to drain the rear diff to pull an axel out to replace a rear wheel axel seal. I couldnt get the fluid brand that I wanted to fill it back up so I had to go with brand from Wal Mart I never heard of. Now I notice some noises coming from the rear end when I start up from dead stop, kind of in the way that you describe.

Last time I changed my fluid in the pumpkin I used Royal Purple and had no issues with it which looks like it had this additive already mixed in.

Thanks.

 

Sounds like a bearing to me. That's the kind of noise you get when a bearing is getting bad and you're putting more of a load on it while turning or going around a curve because the weight of the vehicle shifts and puts more weight on the wheel or axle bearings.

 

I just developed the same problem in my 01 SCrew 2wd w/ 105k. Jpopviens, what's your mileage? It groans & vibrates when turning either way with power on (not when coasting). I figured it was the diffy since it was only when turning and only when power was applied.

Trans guy said he hears a little noise in the diffy, but doesn't think that's the problem. Had the trans fluid changed (just drain, filter, & refill - was due anyway) with no improvement.

So I turned to the net & found over and over as Ash said above that the friction modifier in the diffy might have worn out. OR that the differential clutch pack might need to be changed. Before doing a full diffy fluid change, I'm going to just add 4 oz. of friction modifier & see what happens. If it helps, I'm going to drain & refill with the proper amount of friction modifier. If it doesn't help, I'll have the clutch pack replaced. I read online it's about $100 in parts.

Ford has TSB's on this issue:

TSB 05-23-3 REAR AXLE NOISE REPAIR (includes 01 SCrew, but this doesn't seem to be my problem)

TSB 04-24-20 LIMITED SLIP AXLE CHATTER, SHUDDER, BINDING SENSATION, OR VIBRATION DURING LOW SPEED TURNING MANEUVERS (includes only 04-5 SCrew but sounds more like my problem.)

Good luck & thanks all for posting problems & fixes. It helps a lot! (Me at least).