need help with whining moise

I have a high-pitched whine that I am unable to identify. This whiningnoise sounds when I remove my foot from the accelerator and coast. It is there regardless of the speed. Once I return my foot to the accelerator, the sound goes away. The vehicle operates normally with no niticable problems. It always starts immediately when the key is turned.

So far, I have replaced the transmission filter and fluids, replaced the perfectly good brake pads, rotated the tires. I was going to replace the wheel hubs and ran into problems removing the hub nuts. Simply replacing good parts can be expensive with no end in sight. Any thoughts would be appreciated.

Sounds like a diff problem, have you checked the oil in the differentials? Either that or leave the wife at home.

Diff pinion bearings on their way home.

+1
Mine did the same when my rear diff bearings were on their way out.

Thanks so much for your responses. While I had checked the fluid levels in the Differentials, I did not consider that they had problems since the fluid levels were good. Thanks again.

My diff levels were good but the rear oil was decidedly suspect - grey/brown compared to the fresh oil in the front diff.

check diff flange for play any other than rotational is a problem

I have removed my rear differential. As I turn the flange that attaches to the u joint, I feel a little drag. Could this have caused the whine? After an eyeball inspection, everything else seems to be ok. Thanks again for your thoughts.

warover said:

I have removed my rear differential. As I turn the flange that attaches to the u joint, I feel a little drag. Could this have caused the whine? After an eyeball inspection, everything else seems to be ok. Thanks again for your thoughts.

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If the pinion bearings are worn the whine occurs on over run as the crown wheel starts to drive the pinion, as opposed to the pinion driving the crown wheel. You are looking for ANY play in any direction other than rotational play which is normal. Sometimes noise will be generated in what to all intents and purposes is a normal bearing with no play, as the bearing surfaces start to pit. Did you not drain the oil first to check for metallic particles?

as wammers says ,there should be some smooth preload (drag on pinion)through bearings and seal, you would have to remove flange and check bearings preferably with pinion out ,but dont undo diff carrier cps without marking which side they are fitted to,what made you pick rear and not front ,

wammers said:

If the pinion bearings are worn the whine occurs on over run as the crown wheel starts to drive the pinion, as opposed to the pinion driving the crown wheel. You are looking for ANY play in any direction other than rotational play which is normal. Sometimes noise will be generated in what to all intents and purposes is a normal bearing with no play, as the bearing surfaces start to pit. Did you not drain the oil first to check for metallic particles?

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I did drain the differentials and each was filled with a black sludge Each of the magnetic plugs had little slivers of metal attached. Racher than attempt to replace the bearings,I decided to replace the differential as a unit. Thus the removal of my differential.

Today I went to a salvage yard (breakers) and removed and purchased a differential. This one rotates, for lack of a better comparison, like a good water pump. It was smooth, unlike the one that I removed from my vehicle. Since I pulled it from an "02" and mine is a '99", it is a few years newer. Moreover, the fluid that drained was more of an amber color.

I will install this "new" rear differential, and see if it solves the problem. If not, I will move on to the front. I am becomong a great change out artist.

Is the "new" diff the same ratio as the old? Did R/R change the ratios between 99 and 02? I am just asking otherwise your front /rear wheels will be turning at different speeds. If there is no info available I would get the front diff off the donor car just to be safe.

tomcat59alan said:

Is the "new" diff the same ratio as the old? Did R/R change the ratios between 99 and 02? I am just asking otherwise your front /rear wheels will be turning at different speeds. If there is no info available I would get the front diff off the donor car just to be safe.

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Apart from 2 pin and 4 pin, I am not aware of any different ratios as long as it's from the same engine type.

tomcat59alan said:

Is the "new" diff the same ratio as the old? Did R/R change the ratios between 99 and 02? I am just asking otherwise your front /rear wheels will be turning at different speeds. If there is no info available I would get the front diff off the donor car just to be safe.

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No diff ratio was never changed. All are 3.54 to 1 petrol and diesel. Only difference being four or two pin planet wheels.

Thanks for clearing that up Wammers. Just remembering the recall on VW Toe rag of my friends, transfer box was turning at different speeds for front and rear. Cost VW new transmission and a full set of tyres

tomcat59alan said:

Thanks for clearing that up Wammers. Just remembering the recall on VW Toe rag of my friends, transfer box was turning at different speeds for front and rear. Cost VW new transmission and a full set of tyres

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Can't see how that can happen to be honest. But it or the diffs would certainly get mashed if diff ratios front to back were different.

Not sure myself but I remembering my friend telling me that for every 15 inch of rotation of the front wheel the rear turned 17in. They replaced the transfer/gearbox, all 9 foot of it (the 5 litre version) and 4 tyres. He also got his old tyres back, they had only done less than 2k miles. This was on one of the first Toe rags made.

Wrong diff/axle assembly fitted in production he thinks

The whining noise is now gone! The source was either the front passenger hub which had a grinding sound and would not turn smoothly or the front differential which had a loose center bolt in the flange that allowed it to wobble. I replaced both.

My vehicle is a 1999 4.0SE (Bosch/Thor) and the doner vehicle was a 2002 4.6HSE. Both vehicles had the exact same differentials that i verified by the numbers inside the differential case. The Hub nut, the Hubs, and the front differential was a mammouth job. In the process, I broke my 1/2" breaker bar, a 1/2" socket wrench, and extention. All are supposedly top quality and guaranteed for life. I finally went to a nearby rental company and rented a 3/4" breaker bar and socket and using a 5' galvinized pipe to remove the hub nut. In addition, I rented a pulley and removed the hub which was rusted to the axle. Now I had to return to the salvage yard (breaker) and go through the same process to harvest the front differential and hub. Those parts cost under $200 and while there, I purchased other parts that I can sell to cover my costs. Returningto my garage, I began the process of cleaning the parts, removing the rust and putting everything back together. The rear differential was easy when compared to the front.

The good part is that this whining noise caused me to:

1. Replace the brake pads and bleed the brakes
2.l Replace the transmission filter and fluid. In addition, I got the Transmission oil pan from the doner vehicle in that mine had been welded. It appeared that the previous owner had attempted to add a dip stick to the transmission.
3. Rotated tires
4. Replaced Hubs/wheel bearings
5. Replaced both front and rear differentials
6. Learned that at age 67, I can still bench press a differential

One more British mystery has been solved.

warover said:

The whining noise is now gone! The source was either the front passenger hub which had a grinding sound and would not turn smoothly or the front differential which had a loose center bolt in the flange that allowed it to wobble. I replaced both.

My vehicle is a 1999 4.0SE (Bosch/Thor) and the doner vehicle was a 2002 4.6HSE. Both vehicles had the exact same differentials that i verified by the numbers inside the differential case. The Hub nut, the Hubs, and the front differential was a mammouth job. In the process, I broke my 1/2" breaker bar, a 1/2" socket wrench, and extention. All are supposedly top quality and guaranteed for life. I finally went to a nearby rental company and rented a 3/4" breaker bar and socket and using a 5' galvinized pipe to remove the hub nut. In addition, I rented a pulley and removed the hub which was rusted to the axle. Now I had to return to the salvage yard (breaker) and go through the same process to harvest the front differential and hub. Those parts cost under $200 and while there, I purchased other parts that I can sell to cover my costs. Returningto my garage, I began the process of cleaning the parts, removing the rust and putting everything back together. The rear differential was easy when compared to the front.

The good part is that this whining noise caused me to:

1. Replace the brake pads and bleed the brakes
2.l Replace the transmission filter and fluid. In addition, I got the Transmission oil pan from the doner vehicle in that mine had been welded. It appeared that the previous owner had attempted to add a dip stick to the transmission.
3. Rotated tires
4. Replaced Hubs/wheel bearings
5. Replaced both front and rear differentials
6. Learned that at age 67, I can still bench press a differential

One more British mystery has been solved.

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Same age as me. What did you do with your other hand.