Okay here is my issue. I have 2007 F250 that developed a whining noise between 45-60mph. The noise was only when you would apply very slight acceleration. If you let off the gas it would go away. Truck has right under 120,000 miles. So I decided it was likely the pinion bearing, so I bought the Timken bearing kit and installed it. Read a ton and watched lots of video's. Once I put it back together I had the same noise. At this point I figured it was the ring and pinion gear. I ordered a new Yukon gear set and installed it. I was hoping I would not have to do this as I have never set up gears before. I opted to use a crush washer eliminator as I think the crush washer is not very precise. So during the test drive I have the same whine, but now only between 50-55mph and it is not as load. Very discouraged at this point. My question - Is this likely because I didn't get the pinion in the correct position (too shallow vs too deep)? The new ring and pinion gears have about 100 miles on them. I have attached a couple pics of the pattern before I put it back together. Thanks for any advice.

 

Someone recently had some Yukon gears installed and they were the cause of his whining. The conclusion is that they are junk.

 

I feel your pain. Watching with interest as I am in exactly the same boat. Whine on acceleration, changed bearings, whine on deceleration. Next, new gears going in. I've had it apart how many times now??? Fingers crossed.

Another possibility - noise is from something else.. transmission, torque converter, ..?

As to the pattern.. I think the sharp line at the bottom indicates pinion slightly too deep. But it's difficult.. mine looked perfect but the gears were still noisy.

 

What are you guys targeting your backlash to... Ford spec or gear manufacturer spec?

 

I would always follow the manufactures spec. If I was using all Ford parts, I would follow Ford specs. If Yukon made the gears, I would think twice what I was doing. I've read some bad reviews lately. Maybe with these tariffs, US companies may just have their stuff built here.

 

So thought I would give an update. I took it to a transmission/differential shop and they confirmed the noise is gear noise not bearings. They wanted $900 to set it up, no new parts. I just thought that was too much so I popped the cover off and inspected the gear pattern. The pattern looked good but just a bit too much towards the heel. I checked backlash and it was 14 thousands (too loose). So I re-shimmed it closer to the pinion and got it to 7 thousands. Put everything back and took a test drive. Still a slight noise at 55mph with barely any throttle, when I let off throttle no noise. It is better than it was. I have about 200 miles on the new gears, I have just decided I am going to run them and see what happens. I suspect one of two things - the gears are trash as they are made in China OR the pinion might need to be a tad more deep. I just don't have it in me to take it all apart again. I lost count how many times I have had it apart.

I never intended on setting up new gears, I thought originally I just had bearing noise. Now that I think back to when I was taking everything apart it appeared that someone might have changed out the seal and did not know they had to re-set the pre-load, which in turn destroyed the original gears.

I will update more as I log miles.....

Here's the pattern after 200 miles...

 

Excellent work! And thanks for the update - please let us know how it goes with more mileage on the gears.