I know a little while ago you mentioned bumpsteer issues with your crossover steering. Did you get a chance to work on this at all and if so what did you come up with?

 

I called O.R.U. they were puzzled too. They said I should do one more thorough search and if nothing is found then go ahead and make a trac bar.
I know I can get a mount on the right u bolt plate, but I haven't figured a way to get a mount on the frame ? Either way its a long way down & it's going to have to be strong. They did tell me to keep it on the same angle (7 deg) as the drag link. What size ends would you use ? I was thinking 3/4" or 1" ?

 

I would think 3/4 would be enough for the trac bar. What a pain in the butt! What kind of front springs do you have?

 

I agree, 3/4 is plenty for that. Are your shackles in the front or rear on your front springs, and how much lift/how soft are your springs?

Didn't you say you aligned it yourself...ever get it doublechecked?

 

The springs are Sky Jacker 6" for a 77.5-79 they ride nice.
I'm going to go down to the frame shop next week and see what they say about the alignment. I know the toe is set right, but caster / camber I don't know, it steered ok before I added 3" in the shackels & hangers.
The shackels are to the rear of the front springs, same as Ivans. One thing that has always bothered me about the shackels is they are pointing to the front 2 deg & moving the frame mount ahead would be a pain and I don't know if I could move it far enough before it would run into the cab mount. However they were like that before I added 3" and it didn't seem to bother anything.

 

mark a.,

I have moved my front spring shackles (reversal as well) rearward to the cab mount. It is, like you said, a PITA!! I have to move mine forward again because the shackle angle is dead vertical....at least they're bolted on now (all those rivets suck).

You don't have a track bar? There's your bumpsteer. I had bumpsteer before I fabbed up a mount on the top spring plate on the pass. side. Now there's none and I have quite an angle on the draglink and track bar, which you know should be parallel.

Cody

 

Mark, one thing you may consider if you have a crappy shackle angle is to use shackles from a rear spring and build a custom mount on the bottom of your frame, like I suggested to Mustang a couple weeks ago. I'm considering doing this with mine but I need to build new front hangers first to get all my measurements and angles.

 

While on the subject of trac bar and bump steer and such, are trac bars necessary on rigs with the shackles in the rear?? (this is for my 81) And thats with only 8" of lift and 35's.

 

Track bars aren't a necessity on leaf-spring vehicles, especially ones that are used off road. Track bars have a tendency to reduce wheel travel and articulation in leaf spring rigs because they cause a bind. Leaf springs like to move straight up and down as they extend and compress while the track bar likes to move in an arc....the shorter the bar is, the more severe the arc.

However, when a vehicle with crossover steering (be it to the knuckle or tie rod) and leaf springs encounters a bump, the axle moves straight up and down while the draglink moves in a large arc...this is where the bumpsteer comes from. As the axle moves closer to the frame, the draglink effectively 'lengthens'. With this 'longer' draglink, the pitman arm is pushed to the driver's side while the front wheels stay straight. This is why the steering wheel turns slightly (or not so slightly) when hitting bumps on a non-trackbar equipped leafspring setup. The track bar FORCES the front axle to move sideways slightly in the chassis when hitting bumps. Sounds kinda freaky, huh? This sideways movement negates the 'lengthening' effect of the draglink and effectively cancels out the bumpsteer.

I can hear it now; "My half ton so-and-so with coil springs has a track bar too! It has/doesn't have bumpsteer.") etc. etc. Yeah, with coil springs, there has to be a member that holds the axle side to side because the coils are designed ONLY to support the vehicle....leaf springs are locating members as well. A factory coil spring suspension has little to no bumpsteer because it's engineered to have the proper angles when it rolled off the assembly line. Start jimmying with it, and suddenly the geometry is off and you've got bumpsteer.

So, Ford decided that track bars on leaf spring solid axles was a good idea. It is...until you lift the truck. All bets are off until the geometry is corrected to near factory specs.

Sorry for the book....I've got another hour until I start work and I'm bored, so I guess you can call this "Cody's theory that's guaranteed to make you want to rip your hair out" for the day.


Cody

 

Cody, I'm thinking the same thing. It steered fine before the 3" hanger drop & crossover. My springs are relatively soft & do have some rebound. The faster I hit a wave in the road the worse it is & hanging that winch & bumper off the front didn't help matters any either. How is your trac bar hooked to the frame ? how many bolts and what size ?

 

Thanks for that info cody thats something a lot of people didn't know, but thats some useful info.

 

Mark,
My track bar is held to the frame with a Tuff Country 4" drop bracket, located in the factory location (beneath the engine crossmember). It's got three 14mm (9/16") bolts that secure it to the crossmember. I have seen different styles for these brackets depending on the mfg'r. My bracket replaces the entire factory trackbar bracket, while others include a flat steel plate that simply lowers the original bracket. Give suspension connection a try...that's where I got mine and the price was great.


I should really get some pictures on here of the entire setup. Maybe I'll borrow my friend's digital camera today and put some suspension tech pictures up....that way I can be cool like Ivan and have all these pictures of HOW NOT to do stuff (j/k, Ivan you do a great job).

Cody

 

I just need some ideas on what the one on the frame would look like so I can make something up. I don't want to have to weld it to the frame if at all possible.

 

I thought people did crossover steering on big lifts to cure bumpsteer? You guys are saying crossover steering actually cause it? Then why do it?

 

I think we've gotten a little sloppy with the terminology (me included) on crossover steering and high-steer.

Crossover steering is what most solid-axle ford trucks come with. The draglink connects to the pitman arm on the driver's side and to the tie rod on the passenger side. Examples of this are: any superduty, 70's era HALF TONS, and pretty well any-era Dodge truck. This is a great steering setup for steering control when articulation of the front axle occurs. The setup has it's drawbacks however like we've all found out when lifting. The higher you lift, the worse the bumpsteer can get. The pitman arm becomes farther from the tie rod where it attaches. Thus, "high steer" setups come in. This setup raises the attachment point of the draglink to the passenger side steering knuckle. This attachment is higher than the tie rod where the draglink previously attached, so the angle of the draglink is reduced. That's what high-steer is INTENDED to do.

A lot of people convert to crossover steering (CHEVY FOLKS and the early 70's era 3/4 ton Ford guys) from the typical 'fore and aft' draglink setup. In this setup, the pitman arm pushes a short draglink forward and backward (instead of a'CROSS') in relationship to the truck and pushes the driver's side knuckle left or right then through the tie rod to the passenger side tire.
This setup works good until the front suspension is articulated and then it's very easy to have the steering wheel cranked to one side and have the front wheels pointed perfectly straight. Although this scenario is possible with crossover steering, the length of the draglink really compensates for this phenomenon.

Both setups are very suceptible to bumpsteer when proper geometry is not attained...it's ALL in the geometry.
Hope this helps. I have to constantly remind myself of this confusing matter and use the right terminology.

Cody