Cummins hub assembly woes

skyhighZJ

skyhighZJ

Gov retirement < needs to live
Joined
May 31, 2012
Location
Aberdeen, NC.
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I have a 97 Dodge 2500 4x4. Dana 60 front. I did the ball joints and axle shaft ujoints as long as I was in there and also noticed the hub bearing assemblies were getting a little tired. I ordered in a pair of them but due to the storm down here in Louisiana things are still a bit hectic getting parts. I went with Napa greasable BJ's and Moog u joints and hub assemblies. I put the passenger side hub in but the other (drivers side) was delayed cause of the flooding and it was coming from Texas. This morning I went down and picked it up and got it all put back together. Went back over my work step by step to verify everything was happy and was gonna head to get an alignment. I didn't even make it out of the subdivision and the drivers side tire damn near came off!! I called a tow truck cause I didn't want the tire to actually fall the frick off and risk messing up more shit. Got it jacked up, tire off, caliper off, and the outer assembly with the rotor fell off in my hands!!! I guess what I'm wondering after that lengthy explanation is what could I have missed?? It was driving fine before except starting to have some worn out parts that needed replaced and I know it was the correct part #. I'm just skeptical that I got the one part that came off the assembly line and just happened to have a deficiency.....
 
@paradisePWoffrd it was torqued according to the manual and a cotter pin. The manual says to torque then push past if needed to accommodate the cotter pin. I did it this way but it seemed a bit much. Should I try torquing then backing off a bit to accomodate the cotter pin??
 
Did you turn it before and/or after installation? If so, did it feel smooth?

It also looked to me as if the axle nut were not tight, which didn't preload the bearings. However, it could have been a factory issue too. Is the other side good? I assume if you can do one side, you can do the other, haha.
 
I did spin it before putting it on the ground and was butter smooth. The passenger side has been fine and I checked it again when I tore the broke drivers side apart. It's still good to go. Only thing I can maybe think is a false reading on the torque wrench maybe? It's not the most high quality one as I don't use a 1/2 inch drive TW much so I got a more "economy" version so maybe time to upgrade. Will double check them when I put it back together.
 
I've seen this happen before on AWD cars where the axle isn't seated all the way or the splines get slightly stuck or crooked because of corrosion. The axle nut can have a lot of friction on an old axle, and a lot of the torque goes into thread friction instead of bearing preload. The axle can then slide along the splines or unstick, etc., after time or with vehicle weight, so now you've got a loose bearing with full vehicle weight on it.

There's not much else explanation, other than the bearing being made too short and the nut bottoming out on the axle so there's no preload. If it was something like a bearing race failure, you'd see broken races which I don't see in the picture.

Either way, there was some reason that there wasn't tension on the bearing, and it would have had to be a huge amount of gap between the races to make the rollers shift enough to feel like the hub assembly was going to fall off in your hands without visible fragmented races.
 
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See those marks on the inboard side of the hub? It looks like those are spline marks where the hub might have been crooked and siezed up instead if seating all the way. That would have made a huge gap, and it may have torqued fine and felt smooth until the splines un-jammed. Then catastrophic failure...

Seriously, you can't have that much slop in an angular contact roller bearing that quickly without broken bearing races unless something was reassembled incorrectly.
 
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The spline marks are from when it fell to pieces and the axle shaft withdrew back into the hub assembly. I have gone back and looked at everything and the threads on the stub shaft along with the threads on the spindle nut are fuct. I hand threaded the nut up to snug the torqued so all I can guess is that the thread held enough to get the torque but then with vehicle load/ making a corner it was enough to pull them apart causing the bearing to unload. I have a stub shaft and spindle nut on order along with the new hub assembly. I also have found desrepency in the torque rating. My Haynes says 120 but the interwebs (cummins forum) hint towards 175.
 
Last set of unit bearings I changed on a Chevy 2500 D-max I cleaned the crap out of the splines on the shaft before re-assembly. Those do not set the bearing preload like these do, so it probably didn't matter as much.
 
Since you have to buy another unit bearing anyway... might as well get a Timken.
 
shawn said:
Since you have to buy another unit bearing anyway... might as well get a Timken.
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Will probably have to be bought online unless Advance or Oreillys carry it. Auto Zone for some stupid reason discontinued all the Timken stuff and replaced it with Moog.
 
Chris_Keziah said:
Will probably have to be bought online unless Advance or Oreillys carry it. Auto Zone for some stupid reason discontinued all the Timken stuff and replaced it with Moog.
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That's shitty. That's the only reason I shopped at autozone.
 
shawn said:
That's shitty. That's the only reason I shopped at autozone.
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Yup and of course they did it right when I needed a new carrier bearing. The Durablast one has lasted less than a year and the rubber is completely shot. Some of the Timken stuff can still be ordered but most was entirely replaced with the house brand ching chong made shit like everything else.
 
Rock Auto FTW. $135 for Timken. Auto zone wants that much for a durashit. The MOOG is $200.

Don't forget: the only thing Timken makes is bearings. That's all they have ever made. Moog is a brand name that Federal Mogul bought and slaps on a wide variety of chassis parts.
 
shawn said:
Don't forget: the only thing Timken makes is bearings. That's all they have ever made.
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Not true.

Not even close. In fact in terms of dollar sales bearings arent even their top producct anymore
 
Well either way, yes, if it were my choice it would have Timken put in it cause they lasted the best in my Jeep Hub Assembly applications but I don't have the time to be down with my DD like that so the next best thing in town (for the money) is the Moog unless Uncle Sugar lets me start taking my company car home :)
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shawn said:
Products + Services

:shaking:
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So you like proving my point?
My company for example spent about $35 mm with them last year buying pressure transducer sensors and relays.

No bearings in that part.
Their engineering services Division is now their most profitable, and HQ'd in NC. Not that I've been interviewing there or anything.
 
Well gentlemen, new Moog hub, new outer shaft, new spindle nut, and new pads (both sides obviously). Had the rotors turned this morning. Got it all back together and torqued to 175 ft lbs on the spindle nut. Seems to be good to go! Thanks for the help.
 
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