So I've learned a few things the past couple of weeks.

I've been looking into outfitting my truck with an OME setup. I'm pretty impressed so far with what I've been reading and with the guys I've spoken with at ARB. OME has a few options in their kits. The one that appeals to me is the light system that provides all around control and ride comfort, and still performs nicely while loaded up. Practical, with attention to finer details, as opposed to over the top, burly lifts that really don't make much sense for daily driver types.

The "kit" I'm interested in pretty much replaces all the main suspension components on my truck:
  • Rear Leaf springs
    Front Torsions
    Steering Dampener
    Front & Rear Shocks
    Greasable Shackles
    Greasable Pins
    Bushings

That kit costs around $1k - shudder - which got me thinking: maaaybe I should see just what exactly I can do with my current setup.

I took a look at my springs. Polyurethane bushings looked like they were in there pretty tight. I'm pretty sure they're making it difficult for the springs to work as freely as they should. The leaves looked pretty dry at the contact surfaces, and, if I remember correctly, one of the friction pads was missing when the springs arrived. I wondered just how much the friction between each leaf could be contributing to my rough ride.

There are three leaves plus the overload. Each one seems pretty burly. I weigh around 185 lbs. and can jump up and down on my rear bumper and I might be seeing an inch deflection. Yeah, it's that stiff.

I loosened the nuts at the shackles and frame hangers to give those poly bushings a little room to move around. They weren't really overly tight or anything; the bushings just looked a little compressed.

Next, I jacked up the rear by my tow hitch, and let the axle sag as I jacked it up. Then I wedged a prybar between the leaf ends and shot in some old NAPA chain and cable lube that I had laying around. Wasn't really sure how well this was gonna work, so while it's not really my first choice of lubes for this application, I was just trying to see if it would make any difference. I think I might go back in in a week or so with some marine grease.

Then I just sprayed that lube around the bushing areas at the hangers and shackles and gave everything a wipe.

Took it for a little drive. I was surprised at the difference. It wasn't night and day, but it was better. The springs are still way too stiff for driving around unloaded, but loosening the shackles and lubing between the leaves seems to have freed the rear end up a bit to move around as needed. It seemed to improve the more I drove it. I can only assume that was the lube working into the bushings, and the bushings themselves may have been shifting/settling into their new, more relaxed limits.

I began to think a bit about how a leaf spring is supposed to work. Never really gave it much thought before. When the spring compresses, it lengthens. Since it's rigid at the frame hanger, that means the shackle has to rotate out to accommodate the additional length, but since my bushings were too tight, I'm not sure how much freedom my shackles had. I did see some red dust accumulated there. A spring with a shackle that can't rotate to accommodate the length of the spring as it compresses pretty much, in theory, can prevent the spring from compressing at all. If the shackle can't move freely, it's like you almost might as well just bolt the axle right to the frame. Anyway, I'm reasonably certain now that the shackles can do their job a bit better.

I'm wondering now whether I should try removing one of my leaves to see if that helps with my ride quality. Obviously my load capacity will be diminished, but it's not like I'm carrying loads of bricks or concrete all the time. With only three leaves plus overload, I'm not really sure which to pull. It's between the bottom or middle, obviously. I would assume the lower, right?

Last edited by yodta; 09/16/09 02:33 PM.

msg - '87 xtracab