Steering Bushings...

[PATCO]

What type of bushing should be used for custom steering? I've seen delrin and bronze. Seems like delrin would not provide enough rigidity. What grade of bronze? Where can it be purchased. Is 4130 hard enough for the center pivot sleeve? Should the arms swing in a vertical or horizontal plane? I've seen both types. What are the advantages or disadvantages?

Thanks, PATCO

[vwguy]

go with heim joints if possible but im not clear what you want to do

[Crayfish]

Are you talking about the pivot points on a crossover steering for an I-beam setup? Be more specific.

[PATCO]

Sorry guys, I'm talking about a swingset type on an A-arm truck. Getting rid of stock type idler arm and pitman arm.

PATCO

[michael]

Since we're on the subject....any good pics of this type setup any where? For an A-arm vehicle. Thanks!

Michael <A target="_blank" HREF=http://jmartin.net/parker/goose.htm>jmartin.net/parker/goose.htm</A>

[Gabe_Lara]

Check out the "Skunkworkz" section.
Wanzak's Ranger has the set-up(crossover I-beam), as well as the Stewart's truggy (A-arm)
Race applications, but it gives you a good look.

[FABRICATOR]

PATCO,
Delrin (with a dynamic pressure rating of 1,000 psi), Rulon or other non metal bushings in the steering linkage is not good practice. Some systems can get away with this because of the leverage involved. The shorter the arms used, the more pressure they will be subject to. If your swing type “rocker” arms were say 9 inches long, the load would be several hundred pounds less than arms that are 6 inches long, just for steering loads. If you factor in rocks and other nasty variables it would be exponentially more. These types of bushings have not proven to be particularly long lasting under high load situations. Oilite (oil impregnated) bronze bushings are OK if you again factor in the leverage ratios. The arguable best bushing is just plain bearing bronze (SAE 660 or better) with lube slots. Aluminum or manganese bronze (Dynamic pressure rating of 4,500 and 8,000 psi respectively) is much tougher and harder but unless you have hardened pins it won’t be advantageous. Even the powdered metal bronze bushings have double the pressure rating of Delrin. You can find what you need at any good bearing supply You may have to order them. They can be ordered plain or with grooves. You can groove them yourself with a die grinder if your are careful. Use a “U” groove, avoid a “V” groove. Don’t go closer than 1/8 inch to the end. Make sure it is supported by at least .120 wall or preferably more steel tubing. Unless you do regular tear downs they should be sealed. 4130 would work for the bearing area but won't last forever, tool steel is not very expensive and much harder. As far as lateral or vertical swing arms, you need to look at how much room you have. Both are compromises to perfect geometry. Rod ends are reliable and fairly inexpensive but won't last very long before getting sloppy. This can be a challenging project. Good luck with it.

[PATCO]

Fabricator,

Thanks a million for the info and the attachment. I know where I can get 660 bronze. What's your opinion on flanged bearings vs a sleeve bearing and thrust bearing?

Thanks again, PATCO

[FABRICATOR]

PATCO,
Flanged bearings are fine as long as things are in and stay in alignment. The flange on most "stock" bearings is fairly thin and will not tolerate heavy loads at an angle. I still don't quite know what you are applying it to. On a racing application, a "swing" type of arrangement can be made to line up fairly well with the tie-rods regardless of wheel position. A "lateral" system is usually burdened with very heavy side loading in up or down wheel positions. This is why the bearing area is very wide, usually consisting of a vertical tube with either one long bushing or two separate bushings several inches apart. The swing systems are generally stronger but not any lighter. One thing people like to do is make the whole package all the way out to the spindles as compact as possible. This is the opposite of what it should be. The components have to be much more rigid and heavy. It also magnifies any slop and wears parts faster. Longer components can often be significantly lighter and they don't detract from suspension performance.

I have included another photo of a truck which uses non-metal bushings. These may be Cast-Molded Nylon or Ertalon 6PA (3,000 PSI). This particular setup was made quite large which is a good idea. Hope this helps.

[PATCO]

FABRICATOR,

Thanks again. You've been a tremendous help.

PATCO