Rear differential whine at 43-50mph

[sportsman70003]

I bought this truck used and it had a roar in the rear differential. It turned out to be a pinion bearing and race was bad. I bought all new components for the rear differential. New bearings, new carrier, new spider gears, new axle gears, new ring gear and pinion. My problem is with all the new stuff I have a whine around 43-50mph and is loudest at 46mph. The whine is there when accelerating and deceleration. I have the backlash set at .007 and have attached 2 pictures off the drive and coast pattern. I can say going to a thicker oil did quieten it down some. Anyone have any suggestions?




drive pattern



coast pattern

 

[BrianandChrissy]

I bought this truck used and it had a roar in the rear differential. It turned out to be a pinion bearing and race was bad. I bought all new components for the rear differential. New bearings, new carrier, new spider gears, new axle gears, new ring gear and pinion. My problem is with all the new stuff I have a whine around 43-50mph and is loudest at 46mph. The whine is there when accelerating and deceleration. I have the backlash set at .007 and have attached 2 pictures off the drive and coast pattern. I can say going to a thicker oil did quieten it down some. Anyone have any suggestions?




drive pattern
View attachment 135317


coast pattern
View attachment 135318

Did you properly break it in according to manufacturer specifications?

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[sportsman70003]

Did you properly break it in according to manufacturer specifications?

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I broke it in with 90 weight for 500 miles. It whined from the start.

 

[BrianandChrissy]

I broke it in with 90 weight for 500 miles. It whined from the start.

Damn...how many miles on the setup now?

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[sportsman70003]

About 700 miles now. I changed the fluid at 500 miles. I went with a thicker oil and it help quieten it down some.

 

[BrianandChrissy]

About 700 miles now. I changed the fluid at 500 miles. I went with a thicker oil and it help quieten it down some.

Maybe dump the fluid after another 300 miles and see if there is still an abundance of shavings. If not, they will most likely quiet down as time goes on. I hope all works out for you bud.

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[sportsman70003]

Maybe dump the fluid after another 300 miles and see if there is still an abundance of shavings. If not, they will most likely quiet down as time goes on. I hope all works out for you bud.

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When I dumped it out at 500 miles fluid was clean with no shavings. I checked the backlash again and it was still .007 where I set it. I'll change it again in a few hundred miles to see if anything shows up. The wear marks on the ring gear looked good.

 

[dexter]

I bought this truck used and it had a roar in the rear differential. It turned out to be a pinion bearing and race was bad. I bought all new components for the rear differential. New bearings, new carrier, new spider gears, new axle gears, new ring gear and pinion. My problem is with all the new stuff I have a whine around 43-50mph and is loudest at 46mph. The whine is there when accelerating and deceleration. I have the backlash set at .007 and have attached 2 pictures off the drive and coast pattern. I can say going to a thicker oil did quieten it down some. Anyone have any suggestions?

What fluid are you using?

 

[sportsman70003]

What fluid are you using?

Started out with Valvoline 80w 90 and I'm now using Red line heavy Shockproof with some lucas oil stabilizer added to it.

 

[BrianandChrissy]

When I dumped it out at 500 miles fluid was clean with no shavings. I checked the backlash again and it was still .007 where I set it. I'll change it again in a few hundred miles to see if anything shows up. The wear marks on the ring gear looked good.

Good news. I bet all is just fine.

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[sportsman70003]

Good news. I bet all is just fine.

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Thats what I'm hoping for I just can't stand the whine.