My 1968 VW Type 2 Bus Conversion

Porsche 911 Rack & Pinion Steering Conversion
by Harold Williams
June 2014

This is an overview of installing a rack & pinion steering in my bus. A lot of folks have tried different steering racks to achieve the same thing: more responsive steering. Regardless of what steering rack one goes with, the common part is the Vanagon steering box. Since I'm an old-school guy, I'll use as many Porsche parts as possible.

Parts list (new & used 2014 prices)

You will also need a short Porsche steering spline section to weld to the long steering shaft that goes between the steering box and Porsche U joint.

I originally thought I'd use the Vanagon steering shaft and U joint from the steering box to the Porsche U joint. I eliminated that joint by rotating the bevel box and making it a straight shot to the Porsche U joint. A .750" o.d. diameter steel pipe would work as well. The dimensions I used are for reference only.

After the old steering system was removed, the front section of the upper torsion tube which houses the pivot arm was cut off, as well as a small section of the heater tube. A new section of heater tube will be added using 2.00" diameter steel flex tubing.

I'll break the installation down to 3 sections in the order I did them:

1. VW steering column to Vanagon steering box.
2. Porsche steering rack to Porsche U joint.
3. Steering shaft between the steering box to Porsche U joint.

VW steering column to Vanagon steering box

I drilled out the 2 rivets and cut off the ears on the Vanagon coupler, then welded a 1.5" long section of pipe to the VW coupler and the Vanagon coupler. Since I wanted to delete the U joint at the steering box, I milled off the right section of the steering box so it would sit flush against the frame rail at an angle that would line up with the Porsche U joint. The upper hole on the right side of the steering box was re drilled at the new angle, and threaded using m10x1.5 tap. A 12mm hole was drilled through the frame rail and a 10mm bolt was used to secure the steering box to the frame rail. Next, a steel bracket was made that bolts to the frame rail using the 4 existing frame rail holes. The bracket bolts to the left side of the steering box with 2- 10mm x 1.5 bolts. The width between the frame rail and bracket is about .250" wider than the steering box so I could shim the box on either side.

• 
  steering box
• 
  steering box bottom

Porsche steering rack

I took measurements from a 911 to get an idea of where to locate the steering rack. With the wheels turned full lock to the right, I measured from the center of the right ball joint to the center of the rack. The rack sits approximately 1.5 - 2" forward of the ball joint. The height was based on the steering column going between the front beam with the shaft supported by a bearing. For the steering rack support 1.250" steel square tubing with a .125" wall was used. The rack support is 26" long, with a 10mm x 1.5 bolt welded in each end. To space the steering rack down .750" o.d. x .375" i.d. steel tubing was used. The i.d. was drilled out to use 10mm bolts. The o.d. was turned to .625" x 1.250" long to go through the square rack support.

To locate the steering rack support I measured 10" forward of the front cross brace and 1" up, which would be the center of the support. A 12mm hole was drilled though each frame rail, and 10mm bolts hold the rack support in place. This allows the support and steering rack to rotate in order to level the steering column. To support the front of the steering shaft a 17mm i.d. bearing pillow block was welded to the top of the lower torsion tube.

• 
  measure horizontal
• 
  measure vertical
• 
  more bracing
• 
  911 rack
• 
  pillow block
• 
  Box to U joint

Steering shaft between the steering box and Porsche U joint

I cut the ears off the 2nd Vanagon coupler and welded it to one end of a 22" length of steel tube. The other end was drilled out, and the short splined Porsche piece was turned down on a lathe to allow the unsplined section to slip inside the pipe. The shaft was installed with all the spline bolts in place, then the Porsche spline section was welded in place.

After everything was bolted up and checked the steering rack support was welded to the frame rails. Two diagonal braces made from .125" thick x 1.5" wide steel were also added to the steering rack mounts and attach at the corner of the side rails and cross brace. Braces were also added on each side and in between the rack mounts. The steering rack is held in place with 2- 10mm x 40mm ARP bolts.

Once the bus gets closer to being back on the road I will add a bump steer kit (either Tarret or Elephant Racing) to reduce/eliminate the bump steer, and re-align the front.