Need Steering Ideas

[69l46vert]

Getting to the point where I need to think about the steering in my 54 4wd build. The stock frame has the shackle at the front and the fixed end at the rear of the front leaf spring.

I have a 4wd P/S box from a 72 that I had hoped to use mounting it pretty far forward using the 72 style drag link pointing to the rear to meet the steering arm just like it was in the stock 72 K2500. (Dana 44)

Is this an invitation for bump steer? These springs don't have a lot of travel, maybe 2 1/2". No lift. They are stock 54 GMC 150 springs. (2" wide 3/4 ton)
Should I turn away from this plan before I even start and start looking at cross steer options? My 44 does have a flat top pass side knuckle.

I noticed in OrrieG's build thread he has the same setup with the shackle at the front. If you read this OrrieG have you noticed excessive bump steer? I won't mind a little but want to avoid excessive bump steer problems.

What about changing the mounting of the front springs so the front mounting point is fixed and the rear has the movable shackle?

This part of the build is the one that I had always sort of kicked down the road because I don't know much about steering (been learning a lot lately though) Two weeks ago I didn't know what bump steer was or crossover either for that matter.
It will be an occasional use vehicle but this aspect has me worried. Any thought or comments very much appreciated. Thanks, Rick

[OrrieG]

I have only driven mine around the block at low speed. But it has the same geometry as the 74 donor truck it came out of. The 74 4wd has front leaf springs. Only difference is on a TF the box sits out about 1.5 inches. On an AD where the frame angles in it my be ok. That affects the driver tire hitting the drag link at extreme right rotation. I know this set up has been used a lot and I have never heard of any problems with bump steer.

Bump steer has more to do with the geometry of the spindle movement in relationship to the springs. In a truck with stock springs, axle and spindles I would not expect any. The factor that might affect it is if the drag link is not parallel with the ground plane. Most bump steer problems I hear of are related to A arm type suspensions where the arms are fabricated out of the normal caster and camber, the arms are rotated up to high (not parallel with the ground plane) or a clip is installed at an angle to achieve a lower stance.

[69l46vert]

Thanks for the reply. I think I'm going to try it. I can set the box so the drag link is level or pretty close. It goes right where the from bumper bolts on so a little rearrangement but shouldn't be too bad.

I shortened the driver's (long) side front axle so the drag link will also be straight front to back. Plus the front tires won't be out past the fenders. It won't cost me anything to do it this way and I'll leave it unless a problem arises later driving it. It would be more expensive although an easy bolt on to rearrange it later to cross steer. And I like the idea of using what I have as much as possible. So far it's worked out great using just junk from the pile.

[OrrieG]

You reminded me that I did have to modify the driver side bumper mount too, but was easy as I recall.

[dyno]

I have 1980 3/4 ton axles under my 58. I mounted everything so that I have a level drag link and have not noticed any problems with bump steer. Yep, driver's side bumper brace had to be shortened and moved forward. Good luck with your project, looking forward to seeing the conversion.

[69l46vert]

Originally Posted by dyno

I have 1980 3/4 ton axles under my 58. I mounted everything so that I have a level drag link and have not noticed any problems with bump steer. Yep, driver's side bumper brace had to be shortened and moved forward. Good luck with your project, looking forward to seeing the conversion.

Thanks Dyno. I guess I should start a build thread. I've been taking some pictures but haven't taken the time to organize them into a thread.
Wow, after checking out your thread I see that it's very similar to what I'm doing. Awesome build! I also shortened my frame only because I had a short box and short running boards. Mine's being built out of the leftover parts of four different trucks. Three 54's and a 72 4wd donor. Your 58 GMC looks great. Very cool model. I used to think the GMC grilles were odd and goofy but now I like them even better than the Chevy cousins.