Why does our M1008 Hop?

[pwrwagonfire]

Drove the fire department's M1008 work truck for the first time in awhile the other day...the truck has always had these problems but I figuire maybe we'll finally get some answers.

Driving down the road the thing HOPS, and shimmies all over the place. Now I realize this thing was not meant to be drivin down I-91...but it is, and its what we got!

Used to have a 200 gallon slip-on unit in it, so the suspension was beefed up.

So does anybody else have this problem with the M1008? Is it simply because of the speeds its been subjected to? Last but CERTAINLY not least....are our lives in danger?


Thank you very much for any responces.


-Tom

 

[rickf]

The way you describe it sounds like what I call the death wobble. The front wheels start shaking side to side. That is a symptom of a loose steering component or more likely bad king pin bushings. Check your spring bushings, tie rod ends and make sure the frame has not cracked around the steering box mounts.


Rick

 

[davesgmc]

well, with all the hype of the PIG FLU going around and in the past we had bird flu. I hope this "hopping" is not the start of a mechanical virus called the bunny flu!


OMG!! I crak myself up!

 

[drewmech]

Sounds like the suspension is either worn or something is bent. I'd give it a solid look over. Maybe that 200 gallons of water bent one of the axles. Could be something as simple as a rim or tire thats warped. Hard to tell without looking at it. I know chevy steering boxes have caused similar issues. Tie rod ends ball joints all those components do wear out. How long has this truck been out of the DRMO lot? I know they'll use forklifts to move the trucks around and normally bend drive shafts while they're doing that.

 

[acmunro]

My death wobble (and now I know why it is called death wobble) was a loose front wheel bearing. Someone installed the wrong locknut retainer, it didn't work and filled the hub assembly with metal shavings. New bearings, races, and seal it is like another truck. A side note: The truck drove fine until the right bump. Once the shaking started it wouldn't stop until the truck was almost stopped, then fine until the next bump.

 

[319]

Do a search on death wobble and you'll get all kinds of suggestions, one or more may be your problem. Best thing to do is thoroughly inspect the entire front suspension and drive train.

 

[pwrwagonfire]

Thank you for all the input thus far, very much appreciated!


Ill deffinately pass this along to the boss...would really not like to be in the thing when a part in the front end decided to go! already found out how well a CUCV can stop with 200 gallons in the back and a family of deer bolting infront of the car ahead front of us....answer is not very well! Blew a brake line

How long has this truck been out of the DRMO lot? I know they'll use forklifts to move the trucks around and normally bend drive shafts while they're doing that.

We've had the truck since 2001...and before that Im pretty sure its been in another district since 96/98, but the forklift is deffinately another aspect to check out!

 

[rickf]

YUP, Had If you have false teeth you will know shaft is bent by the time you reach thirty MPH. If you don't have false teeth you will know around forty MPH when your fillings start to fall out!

Rick

 

[tourdog]

also look at tire balance and like said bent rims try tires first and they are load rated for the weight you have .might be just a bad tire to