Written by Jim Wiseman

Edited by Adam Sparks

I picked up Polluto, a 1970 CJ-5, from the P.O. and drove it home. I was at a loss of words when I hit the first bump! I had some major work to do… if I could only survive the drive home. After working on the front end, resulting in new everything (king pin bearings, knuckle u-joints, knuckle seals, wheel bearings, 11” brakes, hubs, shackles, etc) I still had major steering issues. To see the problem, one just needs to turn the steering wheel and observe where all motion goes. There were two problems: bump steer and steering hysteresis (backlash).

When the P.O. jacked the suspension 2.5”, it changed the steering geometry. Bump steer goes as the tangent of the drag-link angle; you want the nominal drag-link angle as horizontal as possible. The following picture shows about a 15 degree angle. In fact the ball joint on the bell-crank is at its maximum travel in its nominal position! This is not good design and has potentially catastrophic stress when the suspension unloads.

Original steering setup

In addition to the bump steer, the old vehicles also have excessive play in their ball joints. Since the drag link is not coplanar with the tie rod, there is torque applied to the tie rod when any forces are on the drag link. This makes the tie rod rotate (not translate) until the ball joints hit their limits. This causes backlash in the steering and makes for even more surprises when applying the brakes; it is any body’s guess which way the vehicle will go until the steering slop is taken up.

Tie rods

The trick to this whole project was an Adjustable Tie-rod Adapter Stud (SpeedWaymotors.com) that allows you to use 5/8” rod ends instead of OEM tie rods. It is made of 4140 chrome moly and comes in two tapers, GM or Pinto. I think Jeep copied GM. I used two; one for the bell-crank end of the drag-link and another for the tie-rod at the driver’s side steering knuckle.

adjustable tie rod

I elected to go oversize on the Heim joints and swaged rods www.rodendsupply.com. The “Endura 2000” Heim joints are 4130 steel, self lubricating, self sealing with TEF/Kevlar races and have a 5/8” diameter through hole with a ¾” thread. The ultimate static load is something like 40500 lbs, I didn’t want to worry about them failing or dropping off. The length of the swaged rods below for a 1970 CJ-5, your mileage may vary. Scribe the knuckle castings at the ball joints and measure the distance between the center lines of the ball joints, write it down and tell it to the order person at RodEndSupply. They know how much to remove from the overall length to find the swaged rod length. Below is the parts list totaling about $200:

Below is the one power tool modification that was necessary. The passenger side knuckle ball joint taper was bored out to 5/8 and a grade 8 bolt placed in the hole. I did not want to put the tie-rod in the “high-steer” position because I worried about forces on the knuckle casting and clearance between the drag-link and tie-rod. Note the cones on top and bottom of each Heim joint to allow full travel w/o binding on the bolt head. Also 5/8 hardened steel washers are placed between the cone and bolt head/nut. The bolt is long enough (5.5”?) that the threaded body extends all the way through the lower Heim joint and is cut to length.

New ends

Below is an end-on view of the upper drag-link joint. This was a direct bolt-in part using the Adjustable Tie-rod AdapterStud. The adapter stud tapered section was too long and extended beyond the top surface of the bell-crank. Ugly spacers were used to compensate. Note the cone spacer below the Heim joint.

New ends

Below is the driver’s side knuckle. The tie-rod adapter stud is again too long to bolt directly through the tapered hole and needed the ugly jerry-rigged spacers. In this application, the large end of the tapered adapter stud was a tad too small; this required removing about 1mm from surface of the nut at the large end of the taper in order to cinch down the taper.

Driver's side

Once the parts were assembled, the tie-rod was adjusted to the previously measured dimension (you did write it down didn’t you?) and everything tightened up. The first test drive paid back all the design and installation effort. The backlash is totally gone and steering is an absolute dream. You tool down the road and realize you’re no longer steering back and forth like some old drunken bus driver. This configuration is also compatible with a future Saginaw steering upgrade.

Completed setup

Remember, should you, or any of your IM Forces, be caught or killed; the secretary will disavow all knowledge of your existence.

Good Luck!