New CUCV Owner! Has some issues, needs assistance .

[Haswell]

I just recently bought a 1985 CUCV M1008 with 12k original miles! However, when I am driving @ highway speeds & hit a bump, there is a horrible vibration & noise that comes from the front of the truck. Sometimes it will go away on its own, other times I have to come to a complete stop in order for it to stop. I checked transmission fluid, bright pink/red & clean! I also just changed the oil & air filter. I was thinking possibly transfer case? or front end? However putting it in 4hi does not replicate this noise, nor does 4lo. I am truly at a loss although I haven't looked much into it, only having it for a day.

 

[nyoffroad]

Sounds like you have some play in the the front steering and suspension, check out all joints like pitman arm, tie rod ends and king pins for play. It dosn't take much play in two (or more) componants to add up! Research DEATH WOBBLE and you'll find a lot of info, don't worry it's all fixable.

 

[TGP (IL)]

In addition to worn parts as mentioned, Weak sagging front spring will cause Death Wobble too.
As the front springs sag down, it changes the caster setting, which wasn't much to start with.
Tom

 

[ken]

Yep that sounds like the death wobble to a tee. The king pin bushings on the top of the steering knuckles are likely suspects. NY is right. search Death Wobble and you will find a lot of info. Oh yea and try slowing down a bit. It's made to be drivin at 45 to 50 MPH in a column with other vehicles. It's geared too low for highway speeds. Driving a MV at highway speed is like driving a civi truck at 100MPH. It can do it, but it's not a good idea.

 

[D6T]

Can you feel any feedback through the steering wheel? If so, check the frame for cracks where the steering box is bolted to it. You can see it very easily when you open the hood and look down. Well-known design issue with these vehicles, and a preventive or corrective action is easy (search vendors for the solutions).

 

[sandcobra164]

My curiosity is peaked with the statement that the noise does not happen if you are in 4Hi or 4Lo. Have you checked to see if your front hubs are unlocked? They should be anytime you are riding on smooth blacktop. If you find they were locked, check your front differential gear oil. Maybe the previous owner drove around with them locked and caused the front differential to wear prematurely. The Dana 60 axle in your truck is very strong but not impervious to improper use. Check and report back. Welcome to the club. Show us a picture of your new truck, here are some of mine.

 

[73m819]

One more thing to check is the front spring bushings, if these are worn the springs will shift to shift side to side

 

[Tinstar]

When you go in to buy parts, DO NOT say it’s for a surplus Military Vehicle.
Say it’s for 1984 K30 Chevrolet Pickup.
With a few exceptions, that’s all it is.

The Army had Chevrolet keep all the CUCV trucks a 1984 design, regardless of the year it was made.

You will save yourself and the parts counter guy a whole lot of grief and frustration.

 

[nyoffroad]

When you go in to buy parts, DO NOT say it’s for a surplus Military Vehicle.
Say it’s for 1984 K30 Chevrolet Pickup.
With a few exceptions, that’s all it is.

The Army had Chevrolet keep all the CUCV trucks a 1984 design, regardless of the year it was made.

You will save yourself and the parts counter guy a whole lot of grief and frustration.

That is KEY! So obvious I forgot all about it. Most counter guys will have no idea about a CUCV but have no problem with 84 Chevy. I have a couple of the local counter guys educated Re CUCV's

 

[kraut83]

Also, side note.
Change your harmonic balancer asap. If you leave that old hb on your asking for a broken crank. Ask how i know...

 

[Haswell]

Sorry I haven't been replying guys, I've been a bit busy. It doesn't seem like death wobble to me, it's more of a grinding type vibration ( wheel bearing kindve?) But it doesn't always do it. Only when I hit a bump. It's a very intermittent noise. Very loud as well. The truck itself is already loud and the noise that is produced is even louder than that. I'll try to get a video of it sometime.

 

[Haswell]

Also thanks for all the input/advice, I'm going to try to look into this issue soon.

 

[MarcusOReallyus]

Hmmm. How about trying this:

1. Get yourself a mechanic's stethoscope if you don't have one already.
2. Put the beast up on jack stands, all 4 corners.
3. Get under there and start shoving things around. Get rough. Move those suspension parts. Fast and hard, like hitting a bump.
4. Look for movement that shouldn't be there.
5. Listen for noise that shouldn't be there.
6. Use the stethoscope to confirm any iffy noises. (You might need a helper.) If you haven't used one before, you'll be amazed at what you can hear.

 

[Tinstar]

Have you looked at all the information on SS related to the “Death Wobble”?
Threads and videos?
It’s not going away on it’s own and will continue to get worse.

Regardless, you’ll need new parts.
Might as well start stocking up now.

 

[Matt5]

Noise or vibration. Not sure what a "grinding vibration" is...

Hub going bad or not fully disengaged?

 

[Keith_J]

Welcome to the club! On any 30+ year old vehicles, if its rubber, replace it. If its electrical, clean it.

Definitely check wheel bearings, suspension bushings and alignment. Death wobble can be accentuated by bad or improperly adjusted wheel bearings.

I had DW on my M1031 even with only 12k miles on the odometer, the kingpin bushing springs take a set over time. Either shim or replace springs and top bushings, easy fix.