Custom Front Spring Mounts

[Troop ISP]

I am mounting Chevy 3/4 ton front springs under my truck, moving the spring mounts under the frame, and putting the shackles to the rear of the spring. I am mounting the top of the spring shackle through the frame at the rear similar to Ryanroo's. I purchased some front spring mounts from Ruff Stuff Specialties.

My question is this: I would like to keep the front hangers as tight to the frame as possible, but if I do, the front spring eye will be higher than the rear. I looked on line for information on leaf spring geometry, but I am still not sure if it is OK to mount the front spring eye higher than the rear. There seems to be differences of opinions. I have things in place now (vice gripped in place) and it appears the caster would only be a couple of degrees from where it needs to be. I figured I could correct that with shims.

Anybody have some advice? I am new to much of this and I greatly appreciate all I have learned from reading everyone's posts. Thanks

[wrecker]

Fred Wiliams from Peterson's 4wheel&offroad talks about that some in this article. Hope it helps.

http://www.4wheeloffroad.com/project...m37/index.html

[Troop ISP]

Thanks Wrecker. I would guess if the problem in the rear would be oversteer, the problem in the front my result in understeer? There is a lot more science to leaf springs than I thought. One of the places I looked stated leaf springs in the front should be a little wider at the rear of the spring than the front of the springs. The information stated it improved the handling of the vehicle. Still not completely sure for the fronts.

[Panther]

It took me a minute to visualize what you're doing but I believe it's a good thing and I wouldnt shim or adjust anything. Some have had caster issues with simply swapping to a dana 60 but by raising the front spring you accomplish the same thing as shimming the pinion down (to improve caster). I'm not sure what difference you will end up with, how much higher do you think the front will be compared to the rear?

[Troop ISP]

The front spring eye is about 5 inches higher than the rear spring eye (shackle reversal). I put an angle guage on the front axle and the best I can tell it would be about 10 degrees positive caster. I was told to keep it at 6 - 8 degrees positive caster. I thought I could use a shim to get it back to the 6 - 8 range.

[moosejr]

One thing to keep in mind, . .the more positive caster, the harder it is going to be to turn, so you are going to be putting more stress on the steering linkage, steering box, etc. Most cars are designed for 1-3 degrees of caster, so, to me, 6 degrees seems like a LOT, and 10 would be too much, . .just my thoughts, . there are others with more experience on these than I have, . ..

[Troop ISP]

I have decided to fab some custom front hangers and drop the front spring eye down some. I think it will still be a bit higher than the rear spring eye, but if the caster is off a couple degrees I can shim it. I will post pics once things are made.

[wrecker]

More caster=more stable but harder to turn. The D60 in my 85K-30 needed 10 degrees, maybe more.(still evaluating) The death wobble was dangerous and tearing the truck up. I'll take harder turning to avoid the wobble.

[Troop ISP]

I read where too much caster can cause death wobble. I have some newly made front spring mounts made that should put the spring eyes much closer to level, although I think the fronts will still be a couple of inches higher. I will post some pictures of the new mounts this weekend.

As for your truck, I checked with my alignment guy and asked him the specs on an 85 K30 since my axles came out of a 1028. He advised me the Dana 60 on a Chevy one ton is 6 - 8 degrees.

[seddons]

I moved the springs under my frame front and rear to run stock one ton dodge axles on my truck and found in order to level the truck I need to run stock 3/4 ton rear GM springs and 2.5 - 4" lift springs on the front. The problem with this is the transfer case is too close to the front axle to run a standard front drive shaft. So even though, like yours my rear shackles are much lower than the front I intend to cut the welds on the front axle C's and spin the rear yoke up to be able to use a front CV shaft and set and re weld the C's in the 6 - 8% range.