How should I do this? Rear trailing arm

[plym49]

The forward end of the rear trailing arm on the driver's side intermediate axle popped off. The rubber bushing is intact on the pin. The eye of the trailing arm is also OK.

I have the axle chocked, blocked, and cocked so that the eye lines up with the rubber. Was thinking of slightly chanfering the edges of both so they can align more easily going back together and then drawing the eye over the bushing with a large clamp. It might work.

My question is what I should do to prevent the eye from walking off again? One fellow suggested welding a piece of strap across the end of the pin. I guess that could work but I am leery of killing the rubber bushing with the heat, and anyway all of the leverage is on the trailing arm, yes?

Was thinking maybe of crafting some sort of way of caging the trailing arm end in place. Or maybe even steel cable and a few cable clamps?

What do y'all recommend?

 

[SCSG-G4]

Weld a strap across the end of the dogbone. Do a search for 'fixing dogbone' and you should get a number of posts on what to do.

 

[NDT]

Technically those are called torque rods, here they are called dogbones. If one is shot, the others soon follow. Set aside a week of your time and replace them all. It’s no fun.

 

[cattlerepairman]

How did you make out?

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[plym49]

How did you make out?

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Got it pressed on as much as I could. Used an 8" HF c-clamp and supplemented at the end with a bearing separator. I'd have liked to get it seated another 1/8" to 3/16" but at that point the tools were bending.

Have not yet welded a stop onto it. Surprised that the pivot pin itself has a rubber insert, so seems to only be a small ledge to weld onto.

 

[cattlerepairman]

Good effort!
I nevertheless echo what was said before.....consider replacing the inserts. The consequences of a dog bone falling off while on the highway and the axle tilting, potentially shearing a U-joint etc. are likely ingredients for a bad day.

I decided to feel the pain only once, took a deep breath and ordered the greaseable Heim joints from Erik's. The whole issue is a little bit like installing cheap carpet - it is as much work installing cheap crap as it is installing the high quality stuff. It was not a "fun" job per se but the old bushings pressed out ok, the new ones pressed in fine and with the rear of the truck and both axles in the air it went surprisingly well, all things considered.

Driveability is much better and I never understood prior to the change how these rubber dampened torsion bars contribute to axle hop on rougher roads. Truck is so much more calm and planted now.

 

[plym49]

Good effort!
I nevertheless echo what was said before.....consider replacing the inserts. The consequences of a dog bone falling off while on the highway and the axle tilting, potentially shearing a U-joint etc. are likely ingredients for a bad day.

I decided to feel the pain only once, took a deep breath and ordered the greaseable Heim joints from Erik's. The whole issue is a little bit like installing cheap carpet - it is as much work installing cheap crap as it is installing the high quality stuff. It was not a "fun" job per se but the old bushings pressed out ok, the new ones pressed in fine and with the rear of the truck and both axles in the air it went surprisingly well, all things considered.

Driveability is much better and I never understood prior to the change how these rubber dampened torsion bars contribute to axle hop on rougher roads. Truck is so much more calm and planted now.

Thanks for the follow-up but that sort of work is not in the cards for this vehicle, nor should it be necesssary. The only reason it came off is that someone used it as a sideways winch point from the other side.

It will never come off again with a cross-piece welded on.

 

[gringeltaube]

Surprised that the pivot pin itself has a rubber insert...

Just pull it out; it doesn't do anything. It's just a residue from when the raw rubber was injected (pressed) into the mold.

 

[G744]

I've seen what can happen to a 5-ton (and a vehicle next to it n the road) when one of those comes apart at speed.

Luckily, it wasn't my truck.

When they get some 20 years on them and the rubber is tired, they will come apart. They are a maintenance item.

 

[oboyjohn]

The Canadian army had similar issues with the rubber inserts separating from the dog bones. As a safety, we modified outs by drilling a large diameter hole in the middle of the bushing ends, tapping them, and installing heavy washers with a big enough diameter to prevent the bushing from pulling out. If you ever saw a washer tight up against the dog bone during an inspection, you knew that the bushing was separating and was time to replace it.

 

[sue]

Drill, tap for 1/2” bolt, large thick washer
( or large piece of 1/4” steel)
And wala, will never come out

 

[sue]

Drill, tap for 1/2” bolt, large thick washer
( or large piece of 1/4” steel)
And wala, will never come out

And in my brain dead mind, I just saw oboyjhons
Response.

 

[HDN]

Drill, tap for 1/2” bolt, large thick washer
( or large piece of 1/4” steel)
And wala, will never come out

How were those done? Were the dogbones removed and put on the drill press? Or just a steady hand with a big drill?

 

[sue]

How were those done? Were the dogbones removed and put on the drill press? Or just a steady hand with a big drill?

You can do them in place, but as you can see from
Our profile picture. We put the 53” tires on and
of course that required us to spread the axles.
Which of course required us to spread the Dogbones, springs, etc,etc.
So we did them on a drill press, but then forgot about the uppers and just put the uppers in a vise.
But did use good tread locker on the bolts because
don’t plan on doing that job again anytime soon

 

[HDN]

Is there any concern about the torque rod overcoming the washer? I take it there isn't since the Canadian Army has done it just fine. It probably doesn't help that I don't have a clear understanding of how the rods work and what the rubber bushing is supposed to do.

 

[plym49]

I've seen what can happen to a 5-ton (and a vehicle next to it n the road) when one of those comes apart at speed.

Luckily, it wasn't my truck.

When they get some 20 years on them and the rubber is tired, they will come apart. They are a maintenance item.

Well, this one has 53 years on it! LOL. This one is going to get a welded strap as I don't foresee the need to ever dissasemble it again (the 1/2" bolt idea). I will possibly weld straps on the others at some point as a prophylaxis. Would be good insurance.

 

[msgjd]

I've seen what can happen to a 5-ton (and a vehicle next to it n the road) when one of those comes apart at speed.
Luckily, it wasn't my truck.

Me too, at about 56mph, the truck was right in front of me .. We were zipping along and all of a a sudden the back of the truck swerved hard to the left over the line, recovered, and then the rear wheels locked up hard skidding to a stop, the truck almost sideways towards the ditch in a cloud of rubber smoke ... Black marks on the road were impressive, I had to almost lock mine up as well.. Whole event took about 4 or 5 seconds... The tires on one side of intermediate axle had climbed hard against the fuel tank and the tires on its other side were shoved hard against the rear axle tires on that side.. The axles looked messed up bad .. Took the wrecker crew at least a few hours to get it towable ..When it happened I was a PFC with no clue what had actually failed.. We had a class on inspecting dogbones not long after that

 

[msgjd]

What do y'all recommend?

View attachment 909533

If this is gonna be a hi-speed road truck you really should replace the doggies.. .. There are dogbones just like these on certain old commercial trucks too, but all of those I have seen, they have a prefab removable retaining strip that holds a replaceable bushing .. Too bad the military did not spec for that design..

If you choose to pop it back on and weld a strip, , I am surprised nobody has suggested silicone or dish soap yet... Might seem counterproductive, being slippery after it goes back together, but you will need to slick that rubber up to get it back in there.. I used a huge c-clamp just like yours and heated the dogbone ring just a little bit, you don't want it hot enough to burn the rubber.. It will pop back on... When i welded a strip across mine, I used 1/4" or 3/8" x 1.5" flat stock .. The silicone helps protect the rubber to a point before it starts to burn or evaporate. I did the welding in short quick bursts to keep rubber from igniting, then did a slow temper with hot water.. That was in 2002 and still holding up on the M51 it happened to.. The dogbone was old and I was backing up to dump a heavy load of stone on extremely uneven terrain, maxxed out the suspension.. It's used exclusively off-road and on private roads under 35mph