rear end howl


Active Member
Jan 2, 2007
north carolina
umm got my 4.10s insatlled the week after xmas had factory 2.73s that made no noise and now the new ones ar wining so i thought my guy said that clutchs in the track loc diff are worn and the spider gears are whats makin the noise. he suggested a new carrier or rebuilding that one any suggestions on what the noise might be and what i should do with carrier btw its the stock peice
P.S. love the 4.10s and recommend them to everybody:shrug:
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well i notice it around 30 mph and up (acceleration and deceleration) my guy told me that the the rearend components are turnin faster but to me the pinion is the only peice thats rotating at the higher rpm everythimg shoould stay the same, right...
As the RPM goes up the pinion, carrier with ring gear and axles turn faster. Plus the pinion, carrier and axle bearing also turn faster. If you going straight than the spider gears should not be turning. The inner works of the carrier should only be working when the two rear wheels are turning at different speed. ex. going around a corner. This could also happen if the two rear tires are not the same size. You can check this my measuring the circumference of each of them.
sometimes they just whine. A lot of people have the same problem...maybe its just the gears? :shrug:

NO, rear ends are NOT supposed to whine, that is total BS a properly setup rear end no matter what gear size will not whine.. None of the ones I have ever setup using the ford tools for pinion depth have ever whined, and I have done a bunch of 8.8's over the years.

most common cause of gear whine..

1. pinion loosens up due to inproper crushing of the crush sleeve ( undertourqed, old nut used with no locktite, overtourqed, pinion nut removed after sleeve was crushed)

2. improper pinion depth and backlash settings.

Without being there to see the car I can not be 100 percent sure but it sounds to me like your pinion loosened up a bit..
Of course the pinion must be properly torqued with a new crush sleeve, but it is very unlikely that this would be the installation problem.

When using FRPP gears, in almost all cases you can simply install them with the same shims that were in the original setup and it will be okay. What happens is that the techs get too comfortable with this and do not check the pattern and backlash at installation.

The pattern and backlash should be checked ANY TIME that the carrier is removed for ANY REASON! It is a virtual certainty that the unit was put back together without thoroughly checking the setup. If they had checked it and taken the time to set it up properly, it would NOT be whining, PERIOD.

Good luck,
thsanks mbdiagman im gonna pull it down this weekend and make sure every thing is alright with the bearings and stuff im also rebuilding the track loc (they put a new pinion bearing a rear one and not the front one in when the old rear one was good no catchs or anything