This is fliver250's rig... We replaced every bearing, race, seal and joint from the driver's side to the passenger side. Complete overhaul except for gears/pinion.

The project was a success, but the outcome during a test run was a fail. There is a significant howl in the front end in 2WD. This points to bearings/races, I assume, since nothing is spinning in the diff.

We obtained all parts from a very reputable front end shop EXCEPT for the spindle bearings, spindle oil seal and L/R axle shaft dust covers. These were purchases from NAPA and came in a kit. The stock spindle oil seals are all metal and you have to use the grooved, plastic washer/spacer. The NAPA oil seals have the aforementioned washer integrated within the seal's flange, but it doesn't spin freely as the OEM one. Also, during the parts store visit for this kit, they informed me that the spindles on this truck are for the heavier D50 GVWR rating, not the 3650# rating as specified on its door plate. The actual bearing did have smaller rollers and twice as many when compared to the bearings which were extracted from the spindle. All dimensions were the same ID/OD though.

Bearing pre-load was set to 47lbs-ft, backed off and then finger tightened while spinning the wheels, then lock washer appropriately installed and outer nut torqued per spec. There have been numerous discussions about the proper way to tighten the bearing after pre-loading it and it seems per the manual, when you back it off 135 degrees, it seems loose. The 47lbs-ft is out of a Dana D50 TTB manual I used when overhauling my '86 F250's front axle.

Did we set the bearing pre-load correctly for the '97 D50 TTB?
Do you think that NAPA obtained spindle kit is suspect?
Any other suspect areas or ideas?

Thanks,
Jason

 

Does it make the howling noise in 4wd? If not the bearings that allow the hub to free spin may be making the racket.

 

Otherwise I would probably suspect the different bearings napa suggested could be suspect.

 

It howls in 2WD and in 4WD.

The spindle bearings won't have anything spinning within them unless the truck is in 4WD. When in 2WD, the front differential and its axles are not spinning/turning.

 

Which side is making the noise?

Take said side apart and look things over