Diagnosing hub problem

[mbavers]

1984 M1008. Have newly rebuilt transmission (TH400) and transfer case (NP200). When I coast down a hill in 4WD with hubs locked I get an intermittent rubbing/grinding noise. I do not get any noise when I unlock the hubs. I sucked some differential fluid out of the front differential and it is grey in color. Probably whatever I heard grinding is in there. I think if it was metal from the hub it would make its way throughout the differential, as I assume the axle is lubricated with the differential fluid. Is this so?

This all started when I had the rebuilt transfer case installed. Never happened before. The mechanic said the front right wheel had a little play in it and he tightened it a little. I'm getting a little too stiff to work on this stuff anymore lying on my back in the snow and ice. I want to be armed with what the problem could be before I bring it to a mechanic. I removed the hub cover and the grease I could see appears dry.

I do not get any noise under load (going under power or plowing), only when coasting in 4WD, (with the hubs locked in). When I unlock the hubs the noise stops, even with the Transfer case still in 4WD. My main question is: If the hub is being ground up, could that make its way to the differential? It seems unlikely that the differential would go bad just after installing a transfer case.

Thank you for any input.

 

[Chaski]

You have open knuckles on that Dana 60 front axle. Nothing from your hub can enter the differential.

 

[ken]

If it is gray in color that is most likely water contamination. Your rubbing/ grinding noise is most likely from a wore out U-joint. Eather in the axle shaft knuckle. Or the drive shaft. I would also check the check the slip yoke in the front drive shaft for excessive slop or play. With the fluid being gray, I would change it also and look for metal flakes in the oil. And inspect the gear set for wear.

 

[mbavers]

I just checked with my mechanic and he feels sure it is a bearing (I forget which one) on the front axle. I will also look at the universals, but they all looked good last time I checked, and since the noise is only when the hubs are engaged I think my mechanic is probably right. I will also be flushing the front differential. Thanks!

 

[mbavers]

thanks for the info.

 

[Tinstar]

If it is a bearing, I would go ahead and replace them all and all seals also.
While more initial effort and expense, it will be better than doing it again and again when they fail one at time.

 

[mbavers]

Yeah, that's what I'm going to tell my mechanic. Every time I need to bring this thing to town I have to remove 900 lbs of rocks (counterweight to plow), tire chains, and the plow. I usually do my own work, but the last axle and hub I replaced was ten years ago and it no longer looks like fun.

 

[73m819]

IF it was a hub bearing, you WOULD hear the noise all the time when the wheel rotated, not only when the hubs are engaged. I WOULD look at the front 3rd member because it ONLY rotates when engaged (noise IS with engagement only)

 

[Chaski]

There is a third “hub” bearing that gets neglected on a Dana 60. On the inboard side of the spindles, where they bolt to the knuckles there is a roller bearing that the outer shaft gets supported by. The only time this bearing is in play is when the hubs are locked, or the t-case is in 4wd. They are not sealed well, and when they go bad the outer shafts can get chewed up where the bearing rides. Only way to service them is to take the spindles off.

 

[mbavers]

Sounds like what my mechanic just told me........................thanks.

 

[mbavers]

Yes, thanks!

 

[mbavers]

Meant my replies to go to 73m819 and Chaski; thanks both.

 

[mbavers]

Tried replying to Chaski and 73m819 both. Replies not showing up. Don't know why. Thanks all.