Hello,

I recently had the pinion and both outer seals replaced on my 2001 F150 4x4 with 8.8 LS axle. No more leaks but now a ever increasing whine is ringing out from the rear end that was not there prior to work. I took it back to the garage that did the job and they said it was normal. However they used 80W90 and said it didn't need friction mod. To be safe I had the fluid changed again with 75w140 synth. and friction modifier added. (No additional noise on cornering) Since then and about 3000 miles the noise has increased.
Ford TSB says to eliminate rear axle noise you need to replace ring and pinion. Is there any other choice? Can a new crush collar and re-torque solve problem with pre-load issue or is it to late due to miles?
By the way the truck has 123,000 miles and runs like a top. Decided to invest some money but do not want to go over the top. Please advise.

 

Sounds to me like the garage did not set it up correctly. I wouldn't trust a garage that uses dino lube and no modifier in that axle anyway.

 

Usually the ring and pinion come in a set and are changed out together.They are "run in" or matched before they are ready for install.If you just changed your pinion and not your ring,the noise is probably from the two different wear patterns on the ring you left in and your new pinion.Its odd that the shop didn't tell you the two had to be changed out together.Also if they didn't set up your pinion correctly,you'll also get a noise.The pinion depth in the ring and the backlash are the most critical dimensions that must be absolutely right on or you'll have a noise. .001-.003 can mean the difference in a nice quiet rearend or a hum or whine that you hear when you drive.I hope this helped,good luck.( you did the right thing changing your diff.lube and adding the friction modifier)

 

The noise is still present. It doesen't seem to have gotten any worse, however it is pretty annoying (without the windows down and radio up) My unanswered question is: Will a new crush collar and pinion nut re-torque solve the problem? Or is a new ring and pinion set the only answer? There is now about 4000 miles since the seal job. By the way, I did not already change out the pionon, just the pinion seal and outer end seals.

 

That's what happened. They changed out the seal but not the crush sleeve and tourged it back to spec, which crushes the sleeve even more.
They should have marked the nut before removing and replaced it back to that mark without torging it down.
The same thing happened to me on some warrentty work when a seal started leaking and the dealership let one of thier rokkies work on it.
They ended up rebuliding the rear without charge after I told them to check that senerio out. They talked to the tech and yup, that's what he did.

 

my guess would be incorrect pinion preload and now the front and or rear pinion bearing is damaged. Had same thing happen to my truck. Damage to the ring and pinion is unlikely

 

Thanks for the input so far. I also talked with a mechanic buddy of mine. He said that if the whining is constant with or without traction load then the pinion bearings have been damaged. He recommends replacing the front and rear pinion bearing, new crush collar and nut. He also said while in there, I should have the carrier bearings replaced too. But did not think that the ring and pinion themselves would need to be replaced. Any other opinions on that?

 

I would say he gave you good advice. I had the pinion seal replaced at 30,000 then a week later pinion bearing gone dealer replaced but rear had slight whine after. Skip ahead a few years rear slowly gets louder,at 130,000 I did a complete rebuild myself and found pinion bearings destroyed and small bits of metal everywhere. You never know what you will find until you take it apart. I needed to replace everything except ring & pinion(they looked like new) and also replaced clutch paks in trac- loc unit. Nice and quiet now.

 

Well, lesson learned here. Do not let just any garage work on your truck, especially the gears. Quick and easy fix for qualified mechanic. Pinion preload is everything. Bearings were torn up in less than 5000 miles!
New pinion and carrier bearings, runs like a champ now. Looks like my seal job ended up costing me about $700 when all was said an done.
Again lesson here is: Take your truck to a driveline specialist for axle work!

 

Out of curiosity: was the whine always there or did you only hear it when you were under a load (on the gas). I'm halfway done with a pumpkin swap on my 82 with the 9 inch, the old one was howlilng any time you gave it gas and were above 35 MPH. It was quiet any time you coasted or did not have your foot on the go pedal. I'll know for sure this afternoon when I get my gasket and gear oil and put it all back together

 

The whine was constant and increased in pitch the faster you went. It was very noticeable around 45 to 50mph, but again was constant.
The pinion bearing replacement and new crush collar did the trick. The carrier bearings were also replaced but had very little sign of wear.
Truck runs great now. 124,500 and counting!
Good luck with your re-build.
One other thing. I did replace the diff cover due to what looked like extensive corrosion on the outside. But the cover was really solid. So unless you hate the appearance of a corroded cover, don't bother changing it.

 

I'm haveing the same noise in mine, where did you take yours? What was the cost of teh work, so i'll have something to gauge on how much i'm fixing to spend.

 

Chrs_brks

I m in Southeast Michigan and took my truck to a place called "Bill's Transmission" In Taylor. They were recommended by a mechanic buddy of mine. They did outstanding work. The job took less than 3 hours. Labor was $225 and total was $375 ($150) for parts including gear oil, friction mod and a complete "master rebuild kit" which includes: Inner and out pinion bearings and races, both carrier bearings and races, crush collar and pinion nut. Also included new outer wheel end seals and pinion seal. Great deal! I wish I would have known about this place first. I also put on new diff cover , but didn't need to. Just did'nt want to open the axle again. Diff cover at Ford dealer for 8.8 is only $27.

Truck runs great! No noise. Good luck on yours.