Help with whine

[George T]

I have a 2004 ST with 88,000 miles. I have a whine coming from under the car, sounds like like the front differential. It is just a high pitched/whine like noise. The weird part is that if its really cold outside it wont make that noise, or it might barely be heard. But as soon as the weather starts getting warmer, the whine gets louder. I thought it was the left front axle shaft bearing, but that didnt help.



Any advice?

Could it be the pinion bearing? A bad pinion bearing preload?



The whine starts as soon you start driving, until the car comes to a stop. Can be heard up to 40mph (too much windnoise after that). Braking, turning, accelerating, decelerating, putting in neutral doesnt help.



Please, any help would be greatly appreciated. Since it is not always consistent, and only does it if its warm, and sometimes only after the car is driven and warmed up, I cant take it anywhere to get it diagnosed. (nor can I afford 90 bucks an hour for diagnosis):sad:

 

[Brad Schultz 2]

Which bearing did you replace? Was it a hub assembly?

 

[George T]

The axle shaft bearing...the side bearing in the actual differential, right where the cv axle goes into the differential. The noise was happening before that though.

 

[Vic Sorlie]

Methinks you're not hearing it when cold because the metal(s) involved have shrunk as they do. They expand as heat increases - to the point that the noise starts. I'd try replacing the differential fluid first with AMSOIL Severe Gear 75W-90, as that's cheaper and easier compared to dismantling major driveline assemblies. I'm not familiar with 4X4 front wheel bearings, but could it be that one of yours needs grease? Examine your CV boots for cracks too.

 

[Brad Schultz 2]

Hub bearing noise comes and goes. Did you go over them really well-lift wheel(s) and feel for any grinding or play in the bearing? Not serviceable; you have to replace the whole hub. Very common in the 4x4s.

 

[swshawaii]

Vic- Any reason you recommend the 75W-90, and not 75W-140 that Ford specifies in their TSB? (05-23-3)

I'm using Amsoil SG 75W-90 in my open NLS differential with hopes of a small mileage increase.

Results have been excellent with no detectable noise or whining. (Tag did not show fluid type)

 

[Vic Sorlie]

Steve, from George's writeup, I took him to mean he's talking about his front differential, which takes a -90 viscosity lube. Many Ford rear diffs call for 75W-140 synthetic gear lube, but not this one. See link below from our Online Lookup. In George's Trac, 75W-90 Severe Gear would be appropriate for both diffs.

 

[swshawaii]

Thanks Vic, I need to read the complete OP before asking questions. :banghead:

 

[Vic Sorlie]

No prob - I'm here to help. Check out my latest article on Oil Analysis in the Project section. Thanks!:haveabeer:

 

[George T]

I actually replaced the front differential like 10,000 miles ago approximately. As well as the front hubs. I ve checked, and there doesnt seem to be any play or anything going on with the hub bearings.

Wouldnt the noise change when you turn too?

 

[EddieS'04]

kick the mother-in-law out of the trac.....:bwahaha:



Sorry, couldnt help it.:driving:

 

[George T]

:bwahaha: I was waiting for that one

She rides in the bed, no touching the leather seats for her :grin:

 

[Roy Prescott]

My 01 st 4x4 also has the same wine i had an exhaust leak and tranny rebuild at the same time and afterwards was hearing the wine. i assume i started hearing it now bc my leak was at the headers causing the truck to be real loud. i thought maby something with the tranny. had the shop rebuild it and nothing changed also made them look into it and they told me maby idel pully had them checked and still nothing. the wine is heard in the vehicle and under whines in park at a stop driving .... all the time with speed it almost sounds as if it wines up like a super charger. my next guess is to crack open the maf and check maby a broken piece catching air under suction making wine? as im out of town right now it will be in a couple days.