Dana 30: How to Diagnose bad Pinion bearing?

NW-ZJ-SCOTT

TEXAS-JT-SCOTT
NAXJA Member
Location
NE Texas
I have had a front end noise for a year now, It's a LPd30 over the last year i have replaced the following

Both Unit bearings
760x U joint Axle shafts
XJ front Drive shaft..
Spartan locker


The noise i am hearing is a rotational metal "Clanking" noise.. its pretty mute, with the radio off its Very apparent though.. enough for a rear passenger to question it.. None of the above "Changed" this noise, but this week it has gotten worse.. And my "Imagination" has me thinking the pinion bearing is going bad..

I know for a fact the "Pinion nut" was NOT tightened enough when i installed the U-joint Yoke.. I think it only got torqued to about 50-75ft/lbs and my research today says it should of been at like 175 or 225?


I have a HP30 and D44hd that i was planning to Truss/gear in february.. but something needs to be done "NOW" before my wife is left stranded.. I am thinking about yanking shafts, installing Stub shafts for now, and yankin the driveshaft/Carrier until Feb
frown.gif


How can i guarantee the pinion bearing is my problem?
 
Are you sure you didn't blow another bead. :D



Grab yoke, and feel for any sort of play in the bearing. Any sort of vertical or horizontal play could mean the bearing is going out.

Typically a pinion bearing will be a more high pitched squeal considering the rpm the drive shaft sees.

Could be a carrier bearing. Same procedure applies. Pop the cover and see if you can find an play in it. Both the carrier and yoke should be "tight." Any noise coming from the carrier bearings will typically match the speed of the wheels.

If I had to guess I would say u-joint or drive line related. Harmonics on a jeep can be a tricky thing.
 
A pinion bearing is more apperant if the veh is at a consistant speed over about 30 or a very slight decelleration at high speeds, IE at 60 mph you put it in netrual and let it coast. If that makes the noise more prodominent then that, mixed with the fact that if you didnt loosen up the pinion bearing preload with changing the yoke, that is likely your issue.

The low pinion has a crush sleeve that takes a 3ft breaker and yoke holding tool to crush, or a very very good impact running about 90psi or more. SO the odds that you got the crush sleeve to tighten down more then it was before you got the yoke off, is slim. I would get under there and try to see if you can get the pinion nut to tighten down just a tad! a impact is the easiest but you have to have a high torque one and then just hit it a few times with it. Then reassemble it and see if that changes it.
 
Pulled front D-shaft no difference..

Long side axle shaft has a Toasted U-joint. missing a cap on one side and two other caps are missing bearings..

Found my noise
 
ehhh wrong..

Even with the CV shaft, the "Clank" is gone, but the "Groan/grind" is still there.. Somewhere there is a bad "bearing" Weather its Hub, Pinion, Or carrier..

I've pulled both hubs off and both of them glide smooth and feel very tight.. No side to side play..


Are you sure you didn't blow another bead. :D
I actually Have blown a bead since the tree run..
In my driveway.. But on purpose.. I had to vacuum out the 2.5 gallons of water out, Rob also had 2+ gallons of water in his tire.. but his was easy to diagnose because it was in the front and caused a deathwobble
 
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Does it make the noise at very slow speeds as well? Say less than 5mph?

If so my vote would go towards a wheel bearing. Mine currently are toast. They can make some god awful sound.

Jack up the front end and grab the tire at 3 and 9, and see if you can notice any movement in the hub. Do the same for 12 and 6.

Does it sound anything like this?

http://www.youtube.com/watch?v=CmuUASXlPYw&feature=related
 
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Am I missing something?

Why isn't this in OEM Tech?
 
Am I missing something?

Why isn't this in OEM Tech?
If i would of put it in OEM tech, they would of "Complained" it was for a ZJ..

if i put it here, they will complain that is is the same d30 tech as the XJ

lose lose situation:lecture:
 
If i would of put it in OEM tech, they would of "Complained" it was for a ZJ..

if i put it here, they will complain that is is the same d30 tech as the XJ

lose lose situation:lecture:

Ok, so it is for a ZJ, then it belongs here--I didn't see that in any of the posts. Besides, at my age, I get confused zipping my fly.
 
a pipe wrench is useful for diagnosing the pinion bearings.
Attach pipe wrench to yoke, attempt to rotate yoke, look for play.

I did my own D30 pinion yoke replacement 2+ years ago and it was cake. I did not do the carrier bearings or anything and it was cool. pipe wrench and an impact are really useful to have for the job.
 
How else would you propose to hold the yoke in place while it's torqued to spec when there's no carrier in it?

Most people aren't going to have the ginourmous open end wrench required, and if you can hold a pair of channel locks that tightly while you torque it to nearly 200 ft lbs with your other arm you're a better man than I.
 
How much rotational play should there be when i try to spin my front driveshaft by hand?
I can see the pinion/yoke rotating in my d30 when i grab the front shaft and spin it.
 
How much rotational play should there be when i try to spin my front driveshaft by hand?
I can see the pinion/yoke rotating in my d30 when i grab the front shaft and spin it.
It's probably just the slack in the spider gears.

There should be something like .008" backlash (play) in the ring and pinion. Sometimes you can feel it by turning the yoke back. The rest of the movement is likely from the spider gears or locker. I know with my Aussie there's a good amount of movement, but it's just the design of the locker.
 
It's probably just the slack in the spider gears.

There should be something like .008" backlash (play) in the ring and pinion. Sometimes you can feel it by turning the yoke back. The rest of the movement is likely from the spider gears or locker. I know with my Aussie there's a good amount of movement, but it's just the design of the locker.
x2.. spider gears just wear weird and develop slop.. nothing to worry about IMO.
 
It's probably just the slack in the spider gears.
The rest of the movement is likely from the spider gears or locker.

x2.. spider gears just wear weird and develop slop.. nothing to worry about IMO.

Thanks guys!
I'm all stock, no locker, and didn't expect this much movement.
Next time we're together, maybe you can twist my shaft and see what you think.
 
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