Hey all,
I have a 99 f150 2wd automatic. It has 287K miles on it and recently has developed a problem.

While turning to the left there is a noticeable grinding noise. I believe it is the front end, but sometimes I think it might be coming from the rear. The grinding noise usually occurs when I am accelerating from a complete stop and turning to the left. Occasionally it occurs under the same circumstance while turning to the right, but not near as frequent.

Any help will be greatly appreciated as I don't have any idea where to start working on this problem.

TIA

 

I'm assuming the noise gets louder the faster you travel?

If so, my guess is a wheel bearing. Jack up the front end and spin the wheels with your hands.. If you still hear the noise/there is more friction than normal it is most likely your bearing.

 

Thanks for the reply.

The grinding noise ends after completing the turn and does not get louder. Later on today, I'll jack the truck up and see if there is friction while turning the wheels.

If it is not the bearings is there any chance it is an issue with ball joints?

TIA

 

i would also guess wheel bearings.. when u jack it up, wiggle the wheel left and right.. if there is play then its the wheel bearing

 

Went ahead and bought inner and outer bearings for both front wheels. Planning on changing them out tomorrow morning. With the mileage on the truck it probably needs to be done anyways.

Thanks for the input.

 

If it only happens when turning, check the rear axle and see if it has a limit slip clutch (should say LS on the tag or marked on the door jam.) If so, im guessing the clutch is grabbing when you turn. Two rear wheels turning at different speed... will not make the noise when going straight line. YOu need to add a bottle of friction modifier to the rear axle. You can get at Auto Zone 7 oz, for about $10. If you have original lube, it might be time to change that, and add the modifier with it.

 

Fluid was changed about a year ago when I replaced the seal where the yoke goes into the rear diff. I'll look into the friction modifier.

Thanks.

 

some door codes

F-150:

19 – 3.55 Non-LS
18 – 3.08 Non-LS
H9 – 3.55 LS
B6 – 3.73 LS

 

Thanks

 

Update to the problem:
It was the rear end causing the grinding noise. I replaced the fluid with Synthetic 75-140 and added friction modifier. The grinding noise / sensation is gone and I have not had any other problems with the truck.

Thanks for all of the input y'all offered.

 

Can anyone tell me if this could be an issue on 04 4wd Expedition. I'm gettine this noise when on the road anytime the steeing is turning left. I replaced both front hubs and that did rid me of some other noises, I just still have this little issue.

The ABS is also on and that code is reading C1165 Right rear speed sensor input malfuction, not sure that has anything to do with this but when it comes to wheel speed anything possible.

Could it be diffrential fluid and do I start in front or rear.

 

if it happens ONLY when turning, and you have a limit slip rear end, then the oil addative is a good bet for a fix.

 

I dont know Steve ...not seeing anything LS

 

http://www.ford.com/resources/ford/g...ITIONsep09.pdf