Front axle rotational play causing CLUNK CLUNK?

[Rohls]

Hi All,

 

Welp, still have this clunking noise from the front end of my MJ. So far I replaced the following in the last 8 months...

 

LCA/UCA and bushings in axle

Drag link and ball joints on both ends.

Ball joints

all u-joints

Track bar is an adjustable one, curry joints...pretty new...tight on both ends

JKS discos

sway bar bushings

Drilled out the UCA bushings to accept a 1/2" bolt, have not done the LCA, but those seems tight...

Rebuilt shocks

 

The clunk-clunk-clunk happens a little more when I am 'off weighting the front end a little' (accelerating uphill) and maybe a little more when I turn left. Definitely noticeable at speeds under 25 MPH...I can't really hear it when in 4WD i don't think..

 

I've driven it without the front axle attached and it still makes the clunking.

 

I've driven it without the sway bar quick disconnects connected...still makes the clunk=clunk=clunk...grrr.

 

I'm starting to think the only thing left really is the following:

 

1.Wheel Bearings: spin freely though, and not any play that I can tell (lift front end up, rotate, grab and shake)

2. Front differential/ gear slop?>>>>I say this because when the truck is on the ground, in gear to keep from moving, I can rotate the front axle (spin) probably 1/4 turn in each direction IS THIS NORMAL? Does this mean I have SLOP IN THE DIFF GEARS? Transfer case belt worn?

3. LCA arm bolts: they seem tight, but maybe not enough? I cranked the holy hell outta them, but think the torque spec is like 130 ftlbs? i don't have a wrench for that.

4. Front differential bearings? Throwing this out there, but man, i don't know anymore.

5. I'm using shocks that are for a 4' lift, but I guess technically I have a 4.5" lift? Could this be the issue? I am getting a winch (on order) next week, and think this would weight down the front some..hmm

 

 

Thanks for your help!

 

 

[Eagle]

I do not understand how, if the truck is stationary with the wheels on the ground and blocked so it can't move, you are rotating the front axle. Are you crawling underneath and putting a pipe wrench on the axle tube? Or are you referring to the front driveshaft?

[Jeep Driver]

Tighten the four bolts on the TB mount, frame side. 

 

 

[Strokermjcomanche]

Have someone (or yourself ) underneath the truck ( making sure you're safe of course ) while someone else is turning the steering wheel and try to locate it that way . You can also try a prybar to see if anything has play in it . 

[Pete M]

my go-to mystery noise is the exhaust banging on the crossmember, but admittedly this doesn't seem likely in this scenario.  when's the last time you changed the gear oil in the diff?  maybe it's time to take a peek inside?  

[Rohls]

14 hours ago, Eagle said:

I do not understand how, if the truck is stationary with the wheels on the ground and blocked so it can't move, you are rotating the front axle. Are you crawling underneath and putting a pipe wrench on the axle tube? Or are you referring to the front driveshaft?

 

My apologies, I meant front drive shaft.

[Rohls]

5 hours ago, Pete M said:

my go-to mystery noise is the exhaust banging on the crossmember, but admittedly this doesn't seem likely in this scenario.  when's the last time you changed the gear oil in the diff?  maybe it's time to take a peek inside?  

 

Yeah, I'm starting to think it is diff/gear/front axle related.

 

I probably changed the front diff fluid 20,000 miles ago.

 

I don't think it is the exhuast, but I'll check it out anyway.

 

How much front driveshaft play is allowable? There is only rotational play, nothing vertical, etc.

 

My buddy thinks the front axle could be bound up within the differential gear...is that possible? It's sounding more like I need to pop off the diff cover and check it out...but what should I look for? The gears have a little backlash / play in them, right? But it sure seems like more than they should...

 

Thanks again...!

[Rohls]

A little update;

 

installed new tranny mount, no change in clunking / rattling noise. Old mount had little cracks in it, but not bad. New mount didn’t line up worth a crap, so had to drill / choose my own adventure in the cross member. I hate that.

 

installed new motor mounts from Ironman 4x4. These set me back $130...I was expecting good results. Finally slammed them in last night, drove around and almost vibrated my fillings out of my teeth. Man, that’s crazy vibes. I did go from cracked rubber mounts to poly, but how bad is it supposed to be? I mean I can feel every revolution of the engine..?!! I let the clutch out and it feels like a shuttle launch in my cab...:/ 

 

I'm stuck again because the clunk is still there...maybe hub / bearing / axle related? Sheesh.

[Dzimm]

35 minutes ago, Rohls said:

A little update;

 

installed new tranny mount, no change in clunking / rattling noise. Old mount had little cracks in it, but not bad. New mount didn’t line up worth a crap, so had to drill / choose my own adventure in the cross member. I hate that.

 

installed new motor mounts from Ironman 4x4. These set me back $130...I was expecting good results. Finally slammed them in last night, drove around and almost vibrated my fillings out of my teeth. Man, that’s crazy vibes. I did go from cracked rubber mounts to poly, but how bad is it supposed to be? I mean I can feel every revolution of the engine..?!! I let the clutch out and it feels like a shuttle launch in my cab...:/ 

 

I'm stuck again because the clunk is still there...maybe hub / bearing / axle related? Sheesh.

Loosen the bushing bolts on your motor mounts, they are likely too tight.  This is the big problem with poly mounts, they transfer a lot more vibration, especially when over tightened.  If you want smooth, go with rubber mounts.  

[Rohls]

3 hours ago, Dzimm said:

Loosen the bushing bolts on your motor mounts, they are likely too tight.  This is the big problem with poly mounts, they transfer a lot more vibration, especially when over tightened.  If you want smooth, go with rubber mounts.  

 

Cool, Thanks. I'll try this.

 

Is there a 'torque spec' for the bushing bolt? I cranked it on there by hand...prolly too tight like you are suggesting.

 

Thanks.

[Dzimm]

12 minutes ago, Rohls said:

 

Cool, Thanks. I'll try this.

 

Is there a 'torque spec' for the bushing bolt? I cranked it on there by hand...prolly too tight like you are suggesting.

 

Thanks.

I don't think you can torque on a bushing like that.  For my rubber mounts I just tightened until the metal ring around the bushing just barely started to bow.    Someone else may have a better way of doing it.  Maybe contact Ironman 4x4 and see what they say. 

[Skorpyo]

Maybe check steering box and frame around it? Seems like you've checked most everything else...

[cody4359]

for browndog rubber mounts you tighten the lock nut til the washer barley moves. literally no tension, and I still habe so vibrations.

for the axle clunk, if there isn't a driveshaft in it I doubt that's the problem. my rear pinion rotates about a half a turn and clunks real bad going thru town on part throttle.

I've had a clunk/creak I chased for a while and it was the bolts on the inner unibody that tighten the motor mount bracket to the unibody.

Sent from my SM-G900V using Tapatalk

[Rohls]

23 hours ago, Dzimm said:

I don't think you can torque on a bushing like that.  For my rubber mounts I just tightened until the metal ring around the bushing just barely started to bow.    Someone else may have a better way of doing it.  Maybe contact Ironman 4x4 and see what they say. 

 

Hmmm...well hopefully when I get back in there to loosen the bolts up a bit, that will reduce the vibes. They are crazy...like being in a paint shaker...

 

My MM are Clevite Rubber, so they shouldn't do this I imagine.

 

Just contacted Ironman 4x4...no response yet.

 

 

[Rohls]

22 hours ago, cody4359 said:

for browndog rubber mounts you tighten the lock nut til the washer barley moves. literally no tension, and I still habe so vibrations.

for the axle clunk, if there isn't a driveshaft in it I doubt that's the problem. my rear pinion rotates about a half a turn and clunks real bad going thru town on part throttle.

I've had a clunk/creak I chased for a while and it was the bolts on the inner unibody that tighten the motor mount bracket to the unibody.

Sent from my SM-G900V using Tapatalk
 

 

Darn, well, I feel your vibration pain...I  would think the MFG would at least mention that the vibrations can increase with the installation of their mounts.

 

Like you said, when my front driveshaft is out, I still hear the clunk....maybe it's the front differential. I can't get to it this next week, but soon enough...

 

Could it be the front wheel bearings? I jack up the truck and spin the wheels...they seem fine with no binding.

 

COuld it be the front AXLE somehow? I mean clunking up and down....?

 

I was noticing yesterday that the clunk gets noticeably BETTER (kinda goes away I think...) when I apply the brakes...so maybe something is in torsion (kinda rotating forward / deadened) by the braking...? IDK...just another data point.

 

Thanks for all the help...I'll keep trying.

[Skorpyo]

So maybe this is a dumb question, but did you check that your caliper mounts are tight?

[Pete M]

did you reach in and shake the  axle shafts looking for play?

[Rohls]

6 hours ago, Skorpyo said:

So maybe this is a dumb question, but did you check that your caliper mounts are tight?

 

Hmm, good point. I'm 95% sure they are but I'll check tonight. What's the torque spec on them,...?

[Rohls]

5 hours ago, Pete M said:

did you reach in and shake the  axle shafts looking for play?

 

How should I do this...? Take off the wheel and hub / bearing assembly? You aren't talking about the axle tubes / housing, right?

 

Thanks.

[DirtyComanche]

8 hours ago, Rohls said:

 

Hmmm...well hopefully when I get back in there to loosen the bolts up a bit, that will reduce the vibes. They are crazy...like being in a paint shaker...

 

My MM are Clevite Rubber, so they shouldn't do this I imagine.

 

Just contacted Ironman 4x4...no response yet.

 

 

 

I don't understand how it could vibe that bad.  My XJ has Energy Suspension poly motor mounts (don't buy them, they're a nightmare to install) and they do not transmit vibrations that are really worth noting.  It's not like an OEM mount, but not much worse.  And chance you bumped a plug wire or something when installing them, and the engine is actually running really rough?

[Rohls]

3 hours ago, DirtyComanche said:

 

I don't understand how it could vibe that bad.  My XJ has Energy Suspension poly motor mounts (don't buy them, they're a nightmare to install) and they do not transmit vibrations that are really worth noting.  It's not like an OEM mount, but not much worse.  And chance you bumped a plug wire or something when installing them, and the engine is actually running really rough?

 

Yeah, it is pretty bad. I thank you for the advise, but i don't think I pulled a plug or anything...

 

I received an email from IronMan 4x4 that told me the torque spec was about 40 ft-lbs.

 

Tonight I loosened the motor mounts ( they were tight) and re torqued to proper torque. Haven't driven it yet.

 

I also went through and torqued the caliper to knuckle bolts; they were really close though.

 

Also went over the LCA and UCA bolts. The LCA bolts were kinda loose-r, but I don't have a torque wrench that goes to 130 ft-lbs per recommendation. just cranked the sh*t outta it. The UCA were tight.

 

Still need to drive her, but running outta ideas.

 

Thanks

 

 

 

[Pete M]

I mean, without disassembling anything, reach in with a giant screwdriver or small crowbar and try to wiggle/pry the front axle's axle shafts around at the ujoints.  

 

[Rohls]

20 minutes ago, Pete M said:

I mean, without disassembling anything, reach in with a giant screwdriver or small crowbar and try to wiggle/pry the front axle's axle shafts around at the ujoints.  

 

 

 

Totally, thanks, I tried this this evening as well, with my hand, I'll try it with a pry bar like you mention. I couldn't detect any play. BUT....

 

I've been trying to understand this: I put a hand on the ujoint (as pictured above) / axle...then another on the front driveshaft and rotate the front driveshaft about 1/4 turn...the axle DOESN"T move. Is this alright? is that too much play in the gears / front differential? Maybe that's where all this crap clunk is coming from? Still need to crack the front differential open  guess...but I don't know what to look for and it's my usual driver.

 

Thanks again.

[Rohls]

As stated previously, I have replaced every single ujoint except the cardon (sp?) joint for the front DS. it looks/ feels fine though.
 Man, i would really like to know what people think about the front driveshaft play though...when i removed the front DS, i still got the clunk, so now I'm really leaning towards the front axle. diff...but what could be 'loose' in there while allowing everything else (4 HIGH, turing, etc,) be totally functional? Strange..

[Pete M]

could be a combination of mild slop throughout the system.  maybe it's time to jack up all four corners on stands, fire it up and put it in drive.  

 

fwiw, my libby has has a thunk in the rearend its entire life and there is fair bit of slop in the rear axle if you hand-turn the rear shaft.  makes a thud you can feel as you let off the throttle.  never gotten worse in 10 years.  It doesn't make a noise though, just a sensation you can feel.