The Stovebolt Site Forums The Parking Lot Big Bolts Front Spring Shackle Position or Adjustment?

1.5 ton Loadmaster Truck. See sig line.

The left front spring shackle pin in the end of the spring was seized. I installed new shackle plates, pins, and bushings. I used a oxy-acetylene torch to heat things up and it worked well. I was surprised to see the pins are threaded where they pivot.

Is there any sort of adjustment or positioning for the shackles or the pivot pins? The way it looks sitting on the ground is that the shackles are all the way forward in the notches of the frame. The right side is in the same position(it was not disassembled). The inside shackle plate is right next to the frame. It looks like the shackle cannot rotate any farther forward. With the threaded pivot pins it looks like the shackle side plate would move away from the frame when it rotates.



I've been looking for a procedure from a manual but have not found anything yet. Any information would be appreciated.

Thanks from Craig W.

Hy craigs380, There is no procedure for "adjustment" of the shackles that I'm aware of. When assemling, center everything, and then tighten the nuts. It sounds like your springs have lost their tension, if your shackles are fully forward with no load on them, hope that helps.

I found the front shackle installation procedure in the factory manual that is online. Thanks to oldcarmanualproject.com. You install the threaded pins centered in the bushings and install the shackle side plates. I jacked up the truck on two jacks and leveled the bumper. Then jacked up the axle to install the side plates. It looks the same as the left side.

It is very possible the springs are weak as they have never been replaced. Either this or the spings are supposed to be this way and the shackles only rotate when the front end rises with a heavy load. There is probably 3-4 inches between the springs and the bump stop rubbers. Maybe a retired engineer or mechanic can explain how they are supposed to work.

I drove and used the truck today. I took it down in the pasture and shoveled about a yard and a half of clay loam soil in the box. That was all I wanted to shovel. I drove back out of the pasture and shoveled most of the soil out of the bed with it tilted up on the hoist. The rest I dumped out in the driveway to fill a future mudhole.

New motor mounts made a huge differnce. The clutch works like it should and I was able to fix the exhaust donut leak. I also adjusted the drag link on the steering box arm. It was loose. The transmission was low on fluid and I filled it. I greased the driveline and the PTO driveshaft. I replaced the fuel guage wire from the main harness on the left frame rail to the tank. I also fixed a couple of tail light wires that were bare.

I adjusted the front brake shoes. It has a great pedal now. I think whoever had adjusted them before had only adjusted the front shoes. The rear shoes were at least 20 notches loose. I thought I was turning them the wrong way. The emergency brake works good and I do not gain a lot of pedal height when I apply the brake pedal with the E brake on. So I think I may turn the adjusters on the rear brakes a bolt flat or two just to make sure they still turn. The rear brakes have been replaced in recent history.

Tomorrow I replace the carburetor throttle body with a good used one I have. It should fix the high idle hang up I have. I do not like a stiff throttle spring. It's hard to apply a little throttle when you need it.

Next big project is rebuilding the door window tracks and latches. I am going to shim the lower hinge to temporarily align the door with the latch. I have a lot of parts to order.

Thanks for the reply! Craig W.

The shackles work in a pretty simple way. Going from the arched position, the spring eye to eye length gets longer as they flatten out. When the main leaf is flat, the shackle is at the maximum extension.

I have installed some leaf springs on a F250 Ford pickup and on a couple of Toyota Land Cruisers and the shackles on them were in the "correct" position. I'd agree that the springs are sagged out. They still work fine. It's supposed to ride like a truck!:-)

I'm curious to find some pictures of new or rearced spings that are installed and show the front shackles. The spring leaves under the top leaf are very stiff. They do flex a little. I can see rub marks at the end of the upper leaves.

I took the carburetor off and compared the good throttle body to the worn one. The good body is off a later model and has too wide of manifold flange stud spacing. I think I'll look around for another throttle body or complete carburetor and have the thottle body rebushed.