Help needed to stop me throwing money at my CUCV, Hopping/Vibration

[Ackevor]

Issue: Feels like rotational mass or a hopping, noticeable slow and steady at 21 MPH, fast and aggressive at 47 MPH (Visors flap), and less hopping and more of a mass truck vibration at around 65 MPH that I cannot pinpoint. If I pay real close attention I can feel it all the time once it starts at 21 MPH and up, just seems to be different nodes of severity. Happens under acceleration, braking, and deceleration.

Parts replaced/bought so far:
New Rear Drive-shaft with U-Joints and Yokes
New Tires
New Drums (complete with shoes & hardware)
New Wheel bearings and raceways in rear
Rebuilt 700R4 swapped in place of TH400 ( I still have it btw, works great torque converter as well as backup)
New U-Joint in Front Drive shaft (Front at Diff only, couldn't find a way to get ones out of the CV joint), however it has no play
New Kingpin Springs and bushings
New Shock Absorbers
New Body Mounts
Purchased new front axle U-joints, rotors, front bearings, raceways, calipers, and pads (Although the rotors and pads look fine, I do hear a squeal every now and then after lots of stop and go traffic, and it is concurrent with the hopping at 21 mph)

Notes: This has happened since I bought the truck a littler over a year ago. There was an insane vibration at 50 which I found the drive shaft to be bent and had it replaced, that vibration has since ceased to exist. After that I noticed the hopping, knowing I was going to need tires and had arranged to get the 700 R4 swap done, I did just that before I replaced other parts. Even after all this its still there. Also when I turn hard to the right, it sounds like my brakes are squealing even without apply the brake, at least something is causing an odd sound, doesn't happen when I turn left (or haven't payed attention)

*Driveshaft has about .020"(front and back) run-out when using magnetic clamp and dial indication attached to rear diff or frame. I should have marked the highs and lows to see if they corresponded with both ends but I was trying a quick and dirty method before I had to run and get my son from Daycare.

*Both Rear rims have about .030" of runout at face of outer wheel on surface where the wheel weights are clamped on. (I checked from one side of weight and rotated to other). From what I hear you wont notice anything under .040"? Haven't had a chance to check front yet.

Ideas, suggestions, complaints, or otherwise disgruntled remarks?

Edit:

I think I could explain it as the feeling of something being out of round. Imaging a tire being oval shaped and you riding along with a budump budump budump budump like something isn't a perfect circle. Owner of the tire place wants me to bring it in (I called to see if they have a way to balance things while installed, ie drum and or tire altogether, they don't), he said they will try a few things and road test after each to see if things worsen or get better, hopefully help me get rid of the wobble. With any luck they will fix the issue. Just depends if I do it today after work, or try to swap old tires first and see if I would just be wasting their time.

Thanks for reading.

 

[tourus]

I would say you still have a balance issue .. if it was me I would remove all wheel weights and put equal in all four tires .. just because you have new drums and shoes does not mean that they are balanced drums.. and front rotors could be warped out of round as well. the noise you hear when turning could be bad bearings in front end. it is a balance issue some where. bent rims even. yes I am sure you had the new tires Balanced but the rest of the rear end is not balanced so put equal in and try it..

 

[infidel got me]

If it were mine I would take it to a tire shop that has a old style wheel balance method. The kind where they balance the tires on the truck. That way you can separate front or rear. Maybe you have a tire that is way out of round. You didn't mention the truck pulling to one side or the other, so the calipers are not hanging up when hot [ can cause a vibration when hot] but a noticeable pull would be noted. Check your front backing plate and make sure its not hitting the rotor when turning, it can scrub the rotor when force is applied during a turn if it is close to rotor. Worse case-- ask tire shop what they think it is. Sounds like you replaced a lot, but sometimes its the simple/stupid stuff that bite us. The driveshaft could be out of balance. Good luck

p.s. I know what it is it's tan. Those tan truck always vibrate -- just kidding

 

[Ackevor]

I would say you still have a balance issue .. if it was me I would remove all wheel weights and put equal in all four tires .. just because you have new drums and shoes does not mean that they are balanced drums.. and front rotors could be warped out of round as well. the noise you hear when turning could be bad bearings in front end. it is a balance issue some where. bent rims even. yes I am sure you had the new tires Balanced but the rest of the rear end is not balanced so put equal in and try it..

I figured the drums would come up, I just would expect the vibration to change or come at different stages going from the old rusted, chunked up ones to new. I really hope its something else as I don't have a press and paid to borrow time on one to reassemble it with the new ones. I plan to stop back in at the tire shop I got the tires from and they said they will look at it for me. I would take all the weights off but they wouldn't want to touch it if something went wrong so I will wait until they have a looksie.

If it were mine I would take it to a tire shop that has a old style wheel balance method. The kind where they balance the tires on the truck. That way you can separate front or rear. Maybe you have a tire that is way out of round. You didn't mention the truck pulling to one side or the other, so the calipers are not hanging up when hot [ can cause a vibration when hot] but a noticeable pull would be noted. Check your front backing plate and make sure its not hitting the rotor when turning, it can scrub the rotor when force is applied during a turn if it is close to rotor. Worse case-- ask tire shop what they think it is. Sounds like you replaced a lot, but sometimes its the simple/stupid stuff that bite us. The drive-shaft could be out of balance. Good luck

p.s. I know what it is it's tan. Those tan truck always vibrate -- just kidding

Thanks for the tip on the dust plates, Ill have to check and see if they are solid and have proper spacing. I doubled checked my drive-shaft to see if after the guy built it if the weights came off but they are still there. If after the whole tire thing, with new rotors, bearings, and axle u-joints don't solve the problem, Ill take it back to him and see what he finds.

I will note that the truck does want to hang slightly to the right when I let go of the wheel, but my new Volkswagen and my wife's Fusion does this, I thinks its the slant in the road. However, when I brake with decent pressure it pulls noticeably to the right, this I figure the new calipers will fix as one is probably sticking, although I can jack up the front of the truck and freely spin both tires so its not seized or hanging up on the rotor.

The tire shop guy suggested when I called yesterday, that it may be tie rods, u-joints, or ball joints but he didn't know I have kingpins. I cant get any play with the tires off the ground, perhaps I'm not strong enough so I would think the tie rods are ok.

Checked Frame around steering box and its good, no cracks and looks healthy.

Edit: Just remembered I have the original wheels and winter tires from when I bought the truck stowed next to my garage. They look like crap and are starting to crack but perhaps I can at least put them on and see if there is a difference? They are studded Mud tires if that makes any sense. I took them off before I found the bent drive-shaft.

 

[73m819]

Just use the cucv as it was made to be used (wheel chock), a lot cheaper, about the only maintenance is making sure the tether chain is not broke.

 

[tourus]

just thought jack the truck up put it on jack stands and start it put it in drive get all 4 wheels spinning you will find out where the vibration is coming from something will be jumping.

 

[Ackevor]

just thought jack the truck up put it on jack stands and start it put it in drive get all 4 wheels spinning you will find out where the vibration is coming from something will be jumping.

You know I did this to find out the rear drive shaft was bent but never gave it a thought about getting all 4 wheels going haha. I will definitely try this. Thanks!

Just use the cucv as it was made to be used (wheel chock), a lot cheaper, about the only maintenance is making sure the tether chain is not broke.

Found the funny guy

 

[NDT]

Could this be classic death wobble?

 

[Ackevor]

Could this be classic death wobble?

No Sir, not that severe. I had suspected perhaps it was the beginnings of it and is why I replaced kingpin springs and bushings.

I think I could explain it as the feeling of something being out of round. Imaging a tire being oval shaped and you riding along with a budump budump budump budump like something isn't a perfect circle. Owner of the tire place wants me to bring it in (I called to see if they have a way to balance things while installed, ie drum and or tire altogether, they don't), he said they will try a few things and road test after each to see if things worsen or get better, hopefully help me get rid of the wobble. With any luck they will fix the issue. Just depends if I do it today after work, or try to swap old tires first and see if I would just be wasting their time.

 

[saddamsnightmare]

October 27th, 2015.

akeover:

You are getting to 65 MPH with a CUCV PU? You must have the 1/2 ton version, as the 1-1/2's were not rated for that kind of speed. Good luck on your hunt, I might ask have you also checked the shocks, as they have some work to do to dampen
the handling issues. As to the pull to the right, I think many good suggestions have been given above, so I won't add to them. On the Unimog S I have I had to replace the front shocks as the MPT tires imposed a different handling issue as opposed to the Swiss NDCC's. Sometimes the tire tread pattern can aggravate handling, operation and noise issues.

If your tires re out of round from the factory, some larger truck shops can cut down the high spots to balance the tires a tis is often how the older OTR truck tire balancing issues were handled. It even works on deuces with NDCC's.

 

[Ackevor]

October 27th, 2015.

akeover:

You are getting to 65 MPH with a CUCV PU? You must have the 1/2 ton version, as the 1-1/2's were not rated for that kind of speed. Good luck on your hunt, I might ask have you also checked the shocks, as they have some work to do to dampen
the handling issues. As to the pull to the right, I think many good suggestions have been given above, so I won't add to them. On the Unimog S I have I had to replace the front shocks as the MPT tires imposed a different handling issue as opposed to the Swiss NDCC's. Sometimes the tire tread pattern can aggravate handling, operation and noise issues.

Its certainly the 1.25 ton, at first I couldnt go above 55mph as I though for sure it would explode. Since the install of the 700r4 I mentioned in my first post, I can regularly drive 70mph in overdrive on the highway at lower rpms than the TH400 did at 55 haha. I love it... well other than the vibrations. I also mentioned I replaced the shocks but thanks for the ideas.

 

[NDT]

Are your u-joints in phase? Let me know if you know what this means.

 

[Ackevor]

Are your u-joints in phase? Let me know if you know what this means.

Yes, after he made the drive-shaft I used this diagram to confirm haha, I didnt know about phasing until I got this truck diagnosing the bad driveshaft when I initially bought it. This page helped me a lot to understand how the driveline should be set up.

Do you do NDT for a living?

 

[NDT]

Do you do NDT for a living?

No, NDT is in the army truck context. Still pondering your problem. Could your driveshaft be out of balance, like the shop left a rag inside before welding it up?

 

[Ackevor]

Could your driveshaft be out of balance, like the shop left a rag inside before welding it up?

I suppose anything is possible, if swapping tires or the tire shop don't find the issue and replacing the rotors, bearings, u-joints, and calipers don't change anything I will be taking it back and see if he can check for runout and re balance it.

 

[NDT]

I think it's the rear drive shaft. I would pull the ds, plug the hole, engage high lock, and drive it to see if there is a change.

 

[Ackevor]

I think it's the rear drive shaft. I would pull the ds, plug the hole, engage high lock, and drive it to see if there is a change.

Man... you guys are full of ideas haha, I didn't even think of plugging the extension housing off the Tcase and drive with front wheels only. Another thing Ill try tonight after work if time permits. My DD is in body shop so I have to ensure its back together and drive-able before bed

 

[alpine44]

Check whether the bearing caps of the U-joint cross are seated correctly in the yokes. I had similar vibrations, albeit not as severe, due to one bearing cap of the rear U-joint cross sitting on top of the alignment boss (red circle in photo) instead of behind it.



(If that is the case, there will be a noticeable gap between the retaining strap/shell and the yoke.)

 

[Ackevor]

Check whether the bearing caps of the U-joint cross are seated correctly in the yokes. I had similar vibrations, albeit not as severe, due to one bearing cap of the rear U-joint cross sitting on top of the alignment boss (red circle in photo) instead of behind it.

View attachment 590482

(If that is the case, there will be a noticeable gap between the retaining strap/shell and the yoke.)

Thanks, I'll double check but I installed the shaft myself and I'm meticulous when it comes to doing things right the first time. Seems like I'll have the shaft out within the next 48 hours anyway so I'll be sure to take a look before I go too far as that can definitely cause issues.

All these ideas and I cant check any until I get home from work at 3:30 Est!

 

[CUCVLOVER]

Could it be a bent rim? Either out of round or the center is warped, causing the tire to wobble? Does the steering wheel shake or anything. Another thing for a quick test you could let someone drive up and down the street while you watch to see if you can tell anything. Also like someone said jack it up block all fours off the ground and try "driving" it.
I would put the other wheels and tires on and see if it changes. Then if it does i would have to shop break down each tire to see if someone left their lunch box or something in one. We all know its hard to find good help.

Also another thing can you tell if the any of the tires and wheels are off center of the hub? If a tire was off center it could be perfectly round and balanced but still act like a lobe on a camshaft.
Hope this help somehow.