Threw a Dog Bone

[Barrman]

I have always felt and heard the rear axles shift side to side when I make sharp turns in both running M35's. Two weeks ago, I took the Gasser on a 40 mile round trip pulling a M105 to get gravel for my drive way. The guy at the gravel pit loaded me up too much. 8.86 tons! I didn't want to shovel it out, so I paid and started home very slowly. The first sharp turn made the axle shift seem very loud. It drove fine though if just a bit slow on the hills. Everything looked ok all over the 3 times I stopped to check.

I got it unloaded and didn't drive it again until going to a Scout meeting this Monday. It drove great, but pulled to the right some. I was thinking low right front tire, right front wheel bearing going out or sticking brake. The tire looked ok, so did all the others. None of the hubs were even warm and non of the brakes had any heat at all in them. I figured the bearing was the problem and just decided to drive slow the 5 miles home after the meeting.

I got about half way home and the truck just didn't want to go fast. I had a guy following me real close wanting to pass. He got so close that I couldn't see his lights in the mirrors even, so I looked out the back. He wasn't that close to me. I was leaving a huge smoke cloud that dimmed his lights! I got off the throttle and he shot around me. Except for the right pull, everything felt fine and the gauges were all ok so I just idled the rest of the way home in 3rd hi.

Everything looked and felt fine again when I got home and nothing was dripping out anywhere. I decided my thoughts on the wheel bearing were still true and went inside planning time to pull the front axle apart. The smoke was still a mystery to me that just might have been dirt on the road or something else un related to the truck.

I looked closer in the day light Tuesday after work and found the rear bottom passenger side dog bone was off its end. There were also rubbed raw spots where the inner tire had rubbed the trunion housing. That explained the smoke and the pull to the right. The rear axle was pushing the rear of the truck to the left. I probably knocked it loose with the gravel load but it wasn't until I drove it on a ruff road empty that it came off the axle.

I know this is a long write up for a simple problem. I just figured there are others like me out there that would think the same things I did when they encounter a sudden front steering pull to one side or the other and not even think about dog bones because there were no noises or vibrations to indicate something was wrong anywhere on the truck.

 

[JTugwell]

i had one of my uppers fall off. truck made a funny noise above 40, but other than that i never knew it had fallen off until i got under the truck to check something else. i went ahead and got 6 new ones. rods and all. i feel much more comfortable now.

 

[Warthog]

Glad you have a spare bone laying around.

If I can replace one in the Ft Sam parking lot, I know you can do it at home.....LOL

 

[Barrman]

Yes, very glad I have a spare. Thanks Joe!

 

[Keith_J]

Fun times to replace. Bringing back bad memories since we didn't have air tools in the motor pool. We had plenty of cribbing.

 

[Unforgiven]

What the heck is a dog bone? Did you happen to snap a photo?

 

[avengeusa]

What the heck is a dog bone? Did you happen to snap a photo?

rear suspension, goes from axle to the frame......

looks lie a "double ended tie rod end" they run parallel; to the frame, cannot miss them

 

[saddamsnightmare]

January 8th, 2010.

BARRMAN:

I am guessing what you refer to as a "Dogbone" are the torsion bars top and bottom in the rear end that serve as control links in the walking beam or live spring suspension? There's a top and bottom set on the right and only a bottom set on the left. Now you've got me wondering, as on sharp turns on pavement my truck shifts the front and rear axles slightly depending on which way she turns, but they always return to aligned front and rear when the truck straightens out. Live spring suspensions without these torsion bars always had problems with too much lateral action for the leaf springs, and so means were devised to contriol that movement through the control links.
The live spring suspension was first tried by the Baltimore and Ohio Railroad under its locomotives and freight cars in the 1840's and by the 1860 period they found out they were too unstable for speeds above the 10 to 20 mph range. I suspect the Army choose this design due to the articulation which was only limited by the springs striking something (the frame generally) to limit the motion. In coil spring suspensions there is always a need for a radius rod or traction bar to control the springs tendency to displace to the rear (or front, depending on the direction of motion) which can seriously alter the handling characteristics.
In modern heavy locomotives we use a combination of coil and leaf springs (as their characteristics combined dampen out the unwanted behavior of either spring unit) along with swing hangers (to permit limited lateral displacements of the wheelsets) to produce a better tracking and ride picture. Most civillian heavy trucks use air bag springs and they can be adjusted for optimum ride characteristics, but few civillian trucks are routinely put through the **** that a deuces suspension meets in extreme off road conditions. The deuce does pretty well unless joint spacing impacts occur at the harmonic value that sets the leaf springs bouncing uncontrollably, when that happens the ride and control issues get "interesting" to say the least. Also figure there are functionally no shock absorbers on the rear end to control these reactions.......I wonder if the bobbed deuce boys see more action (bouncing) without the dead weight of the third axles unit?

Just wondering,

Cheers,

Kyle F. McGrogan

 

[Recovry4x4]

Hmmm, I was out boning out a rear suspension I picked up recently. I collected all 6 dogbones off of it and was contemplating pulling the trunions apart. Just for the heck of it I tried to wiggle them side to side and wouldn't ya know, they had an inch of play at the end of the spring. Trunion bearing/bushing adjustment is worth looking into.

 

[Warthog]

What the heck is a dog bone? Did you happen to snap a photo?

Here is the one I replaced in the Ft Sam parking lot..................

http://www.steelsoldiers.com/deuce/35467-torque-rod-dogbone-replacement-easy-way.html

 

[Barrman]

I checked, repacked and assembled the trunion bearings about a year or so ago on this truck Kenny. Being an old Gasser, it actually has bearings still. The newer trucks have a bushing and a grease Zerk. I imagine those wear a lot faster.

Yes, I am talking about the torsion bars that keep both rear axles lined up and level. The old Gasser dog bones were round (like a bone a dog would eat) and the newer ones look like little I beams with round ends.

 

[Barrman]

I left work at 1630 today, drove 5 miles home in the M715, changed clothes, grabbed a 1-1/2" socket, breaker bar and a big sledge. I took the tools over to the spare rear suspension Wart Hog dropped off in the middle of the night a few months ago, spent a few minutes knocking a good dog bone off and then took it all over to the Gasser.

I had planned to remove the housing that holds the dog bone to the axle, but those 48 year old bolts didn't want to let go. Even with the BFH swung with enthusiasm. Plan B was to remove that really hard to get to one behind the brake backing plate. As everybody knows, you can't get a swing at that one. Plan C was to pry the dog bone itself off the stud, attach a really big pipe wrench to what was left and beat on it wth the sledge. Two whacks got it loose. The new dog bone was put on with a ratchet strap pulling the axle back together. I drove the truck away at 1725. Just enough time for Colton to go drive it through a mud hole we have started to form on our property.

 

[OldDominionIron]

Here's a pic for you, Unforgiven.

 

[davey8943]

Excellent Thread! I'm glad I found it while I was searching for something completely unrelated!

I have noticed that my '69 M35A2 makes a "clunk" when turning from left to right and vice versa. I have taken a look and the springs appear to be wearing the "Dog Bone" hangers. (I'll try to get pics up later).

It sounds exactly like what Barrman described in his OP. My question is:

Is it "normal" to hear the axles shift back and forth? Should I notice any wear from the springs anywhere on the axle housings?

(I assume this means I should take a look at my trunnion bushings, but wanted to get thoughts on it before tearing into something needlessly!)

Thanks,
Dave

 

[rosco]

You should not be hearing any overt noises from the suspension. There will be some signs of spring wear. Its metal to metal fit! Its always good to watch for abnormal wear.

 

[Barrman]

Going slow and doing lock to lock turns makes any M35 rear suspension move around enough to be heard in a gasser or felt if you are trying to feel it in a whistler. Every truck I have ever driven does this. If you want to scare yourself, remove the bed and drive around a field while watching the rear suspension. It moves a lot.

 

[Happyland1410]

Excellent Thread! I'm glad I found it while I was searching for something completely unrelated!

I have noticed that my '69 M35A2 makes a "clunk" when turning from left to right and vice versa. I have taken a look and the springs appear to be wearing the "Dog Bone" hangers. (I'll try to get pics up later).

It sounds exactly like what Barrman described in his OP. My question is:

Is it "normal" to hear the axles shift back and forth? Should I notice any wear from the springs anywhere on the axle housings?

(I assume this means I should take a look at my trunnion bushings, but wanted to get thoughts on it before tearing into something needlessly!)

Thanks,
Dave

Here is a thread from when I found out my spring seat bearings were shot. Unfortunately mine had been let go long enough (by the army) to strip the threads on spindle. Mine had a huge amount of side to side play at the end of the springs.

m35 A2 rear axle alignment.

Just got back from an alignment shop. Mechanic showed me where the middle axle is seriously out of line. Encountered this before on my big truck. It was fixable. Mechanic states he doesn't see how to align the rear axles. Can anyone help with this problem please? I cannot believe this isn't...

www.steelsoldiers.com

Check out TM 9-2320-361-20 section 7-19

Here is another related post to check out:

m35a2 with trashed rear spring seat/tandem axil

Hi, first time posting. First MV an M35a2 LDT465-1D with rear singles. Brought my deuce home yest and was feeling elated until inspected rear spring seats/tandem axil bracket. Left side spring seat and axil bracket trashed and wollerd out. Would appreciate greatly any advice on where to obtain...

www.steelsoldiers.com

 

[bsorcs]

For what it's worth, I was at Mike Arnold's shop today, and he has a remarkable number of what I
think are new 'dogbones' amidst the trove of stuff he wrote abut sometime back. Prices are good.

bs