Wicked front end shake xm211

[Uneasy rider]

Hey all, I found a related thread from 2006, I figured I would refresh the topic of the death wobble. I just bought my mv, 54 xm211 about 2 mos. ago. On three occasions, at aprox. 40, death wobble that rattles the eyes in my head that I can't hardly see. The first time was on the drive home from buying it, the next 60miles was uphill so I never got a chance to get it back up to 40, hah hah. The next 2 times were after inspecting wheel bearings, steering, toe in(1/8") all seemed fine and went to 45 psi, death wobble, increased to 55 psi and again death wobble. Any help?

Unrelated questions.
Off road in the snow (8-12 inches)the front end seems to get pushed more than I would expect. I heard that the front axle engages when the backs are turning 20% faster than the front. When I need the front axle to drive through the snow ( I.e. uphill) it requires the backs to spin at quite the engine rev before I feel the fronts start to pull.
Normal or is there something wrong with the auto front axle engagement?

Side note questions out of curiosity, At any axle, when tires are off the ground and tires are being turned by hand, opposite tire turns backwards( open diff.) when only one tire is off the ground it can't be turned indicating a posi????
Also turning tire by hand with both off the ground why doesn't the driveline turn???

Thanks for any help these are very unique rigs and I am enjoying learning about them. I bought it KNOWING that I was going to bob it but after posting one thread and doing a little research on 211's I simply cannot allow myself to do it. Mine seems to be very original other than the dump bed. Soooo, she's going to have pull fire wood duty and family day trips to our fishing holes in the backwoods loaded dirt bikes etc in her orig form,12 ft bed and all

 

[m1010plowboy]

Tire Balance

Some of the experienced pilots of the 211's suggest front tire balance. The
wobble's very hard on parts right up to the nut on the steering wheel so hopefully there's an easy fix.

Swap tires around front to back with the best on the front.

Remove the large brick someone hid in the wheel.

As for the front axle engage, the sprag in mine is a little 'delayed' when engaging and it's probably from 56 years of wear. You can pull the diff cover and see how everything is working internally and inspect for 'obvious' broken parts.

There's some hilarious trouble shooting in the Technical Manuals TM's including the different noises one can evaluate to determine where problems may be.

Until every part is removed, re-built and replaced she'll always be moody. Get out the wrenches.

 

[lacoda56]

I had a similar experience with an M211. It was converted to a water tanker for the local VFD. At about 50 mph it started to wobble/shake so bad that I just about lost it before I got it slowed down. That's definately a ride I don't want to repeat! The only thing we found was the steering arm bolts on top of the left steering knuckle were just starting to loosen up. Like M1010 said, check everything from the tires to the steering wheel!

 

[nattieleather]

I would check everything in the steering to make sure it's tight. Then I would check the tires for one that is out of round. Balancing the tires also helps. I had a wiggle at 45 mph on my old M211 and I had the front tires balanced and it smothed right out.

 

[JGBallew]

If everything seems tight, check the output shaft of the steering box.
Look for cracks.

Posted images, the truck always had the shakes but everything seemed tight.
Luckily the shaft broke at walking speed. Thank god it didn't happen at highway speeds.

 

[Uneasy rider]

Hey guys, thanks for the tips. I forgot to mention that the guy I bought it from had put brand new fronts on it . As far as balance, use weights or the self balance " sand" that I have only vaguely heard about.

 

[Section8]

Have you considered checking to make sure the tires are seated on the rims proper? Or have you checked you mounting surface on your hubs?
I have driven a couple old ford trucks with the same wheels as the snubnose jimmies, from a couple different construction companies I worked for.
One had a new tire that hadn't properly seated on the rim after being replaced. Caused one heck of a wobble plus ruined a new tire once it let go.
The one with the bad mating surface on the hub had a bunch of rust and dirt in around where the hub meets the face of the rim which caused it to be miss aligned once torqued down. Had a decent wobble and eventually caused the nuts to start stripping and or back off the studs from the wobble.
Just my two cents. I always inspect tire seating and mating surfaces if I am replacing a tire on the axle.

 

[Uneasy rider]

Thanks for your 2 cents. In both your scenarios was the wobble at any speed or one certain speed every time. Mine happens at about the same speed the best I can tell without a working speedometer cable. Any info on speedo cable???

 

[Uneasy rider]

I am suprised nobody has busted my chops over pics, I have been working on it and I think I got it. Here they are, hopefully.

 

[Stan Leschert]

If the wobble happens at the same speed, I'd be looking at the tires first,
but I would have a real hard look at all of your U joints.

A harmonic vibration has a cause, look at the cheapest and easiest fixes first,
and then dig deaper.

 

[Uneasy rider]

hey stan what would be your sugg. for balancing the tires?

 

[Stan Leschert]

Head to a heavy truck tire shop, and bring your wallet!

I have heard of sand ring which bolts on to your tire,
but I haven't tried it, so I can't say if it works or not.

I do know that the old fasioned method of putting weights
on the rim does work.

 

[Section8]

In my one scenario with the tire not having a proper seating on the rim, it was more noticeable at a low speed to start. Say about 30mph. Would increase the wobble after every right hand turn as it would further unseat the tires with the side wall pressure of the turn until failure accord.
The other situation of the incorrect hub/rim mating the wobble didn't really show up until a decent cruising speed of 50mph. Wobble increased over duration of 2 days with starting at lower and lower speeds until I pulled the truck off the road refusing to drive it.
Boss told me to find the problem or drive. Showed the one stripped stud and two that had backed off at the point of the rust/dirt accumulation behind the rim. Caused by what I called a soft bonding with improper torque on the hub.

 

[135gmc]

Assuming that the front end and steering are tight, I would first see if the front wheels are installed correctly - be sure that the Budd lug nuts are seated inside the wheel's beveled holes - its possible to just catch the flat surface of the nuts on the surface of the wheels. It ain't easy, but it can happen.

Then, take a real good look at wheel balance. When the new tires went on, did the tube get replaced? Is the flap in good condition? If all else fails, balance the front tires. I did a balance job, and the results were amazing. Bring your wallet - a truck tire shop will probably charge $ 65-75 per wheel. Its usually cheaper if you haul the wheels in to them instead of having them take them off your truck

 

[butch atkins]

didnt see this mentioned, jack up front axle,see how much shake you can get by grabbing tire at 3 oclock,9 oclock pos.shake well from front to rear, loose/worn out tie rod(s ).first time my truck did it was when i hadhad load of steel beams,front end was light.also check front end toe in (alignment),p406-407 in TM 9-2084.My alignment was really out so it wore out the tie rod ends fairly quick,good luck keep posting,welcome, save the G-749s

 

[lacoda56]

This's what I like about this site. This post has generated a lot of good info in just a few days! With the TM section, search, and just plain asking, we're all getting better at maintaining these trucks!

Ron

 

[richard hines]

I just read about that problem in military vehicles mag .

Read it in magazine a couple months ago. Our 1952 xm 221 does same thing! Pump tires up to the max and see if it happens! Ours has this issue when it sits for weeks ! Tires get flat spots . Takes 20 miles to get them round again. Chances are you are WAY out of balance or out of round . Switch to radials , you will be happier! And check balance on tires !! Then kingpins/ balljoints and tie rod ends at tires , pitman arm etc!
If it's not loose it's out of balance or out of round !
According to article in military vehicles magazine . When this happened in the military ; tm was to pump tires up to max pressure ! Voila !!!

 

[Uneasy rider]

Ok I gotta ask, MAX psi. The newer fronts say 65 psi are you suggesting a higher psi? Also radial 9x20 with the classic tread pattern?How much and where at?

 

[m1010plowboy]

Psi

Never more then Recommended PSI Stamped on tire.


I mean, you can but you can eat every type of mushroom once too......but you shouldn't.

That Rim tire assembly isn't the official 'widow maker' but can kill as quickly if handled improperly. Just a safety note to consider, the assembly has come apart violently while being inflated.

You've got to have some tire sources in Cali.......

.........just did a quick google for "9.00x20 tires california ndt" ........ and 100 dollar man in Lucerne comes up first. Looks like you've got a good selection. Let me know what you find.