Porsche 944 Torsion bar replacement Part 1

In my previous article, The 944 - Making It Stick, I outlined the basic procedures for improving the NA 944 stock suspension package. In that article I left out many of the detailed procedures for the replacement of certain suspension components. The most challenging (read: difficult) of which was the procedure for replacing the rear torsion bars. During my quest for documentation on the detailed procedure for the 944, I consistently came up short. The intent of this article is to share with you the step by step procedure I followed during my recent successful experience at torsion bar replacement in my 1986 NA 944 (from 23.5 to 26mm).

Be warned that torsion bar replacement for a 944 is not a job for the faint of heart. In fact even experienced specialists will reluctantly admit that they have never replaced the torsion bars on a 944. So you’ve been warned, proceed at your own risk. Please note that this particular procedure applies to my 1986 944, your procedures may vary slightly (i.e. different calipers, ABS sensors, etc.). Please also note that this procedure will require that you disconnect brake lines, so all usual brake system safety procedures will apply, i.e. bleeding, etc. .

  1. Lift car onto axle stands on all four corners (approx. 16-18 inches above floor will be required).
  2. Remove rear wheels
  3. Remove rear anti-roll bar and associated drop links.
  4. Disconnect rear brake lines(from caliper) at hoses.
  5. Disconnect brake pad wear sensors (if applicable)
  6. Unbolt rear axles at CV joints on transaxle housing. Place plastic bag around CV joints and seal the bags with tape around axles in order to avoid contamination of CV joints.
  7. Temporarily suspend the CV joints and axle shafts(use any kind of strap) from the transaxle mount cross member (it is located directly above the transmission housing and runs right to left)
  8. Remove the trailing arm to torsion tube mounting bolts that run through the trailing arm pivot bushings (see diagram)
  9. As done with the CV joints, suspend the trailing arm and brake rotor assemblies from the transaxle mount cross member. I find that a good quality cargo hold down strap works best. Wrap the strap around the rotor assembly then up to the cross member.
  10. Loosen the three trailing arm-to-spring plate bolts(see diagram items 7,8,9, etc.). Please note that some are actually alignment adjustment eccentrics and must be gently knocked out from the outside to the inside. ATTENTION, as you remove these bolts the trailing arm and brake rotor assembly will now be free to drop so make certain you’ve tightened up the hanging strap you prepared in step 9.
  11. With the trailing arm free, by slowly loosening the hanging straps now attached to the trailing arm and the CV joint, you can gently lower them to the floor (approx. 16"). The parking brake cable should be long enough to let them down to the floor.
  12. Remove the nut and bolt which holds the torsion tube cantilever arms to their mounts (see diagram item 5)(center-top of the wheel well).
  13. Place a spare tire (or suitable substitute) under the torsion tube assembly. (the best thing to use is a mechanics hydraulic car jack with a suitable jig - my jig is a 12" x12"piece of plywood with a small sand bag on top of it - just raise it up to the torsion tube housing and proceed to the next step)
  14. Remove nut and bolt at torsion tube chassis mounts. The bolts run front to back through the torsion tube chassis mount bushings(see diagram item 14) located in the lower front of the rear wheel wells.
  15. Once the mounting bolts are removed gently pry torsion tube down onto spare tire (or hydraulic jack jig).
  16. Make sure torsion tube assembly is dropped low enough below the chassis so that end caps can be easily removed.
  17. If you want to remove the entire torsion tube assembly from under the car(optional) you must remove the three E clips that hold the parking brake cable onto the torsion tube. Note: you do not need to remove the torsion tube from under the car to replace the torsion bars.
  18. Take a look at the torsion tube end caps and note that their are four bolts that fasten it to the tube. First remove the bolt which holds the spring plate end stop located on the lower rear location(you will notice that the spring plate rests on this bolt). This will unload the torsion bar. Before proceeding to the next step you should make a note of the position of the spring plate in the "un-loaded" condition relative to the torsion tube assembly as this will be valuable information if you decide to put the stock torsion bars back into the car at a later date (doubt that will happen ‘cause after you’ve done this job once you’ll never want to do it again!).
  19. Now proceed to remove the three other bolts holding the end caps on.
  20. Pull off the end caps.
  21. Pull out the spring plates and the torsion bars.

The next step is to insert and properly index the new torsion bars. In order to properly accomplish this task you will require a sound understanding of the index adjustment procedures for splined-end torsion bars (911 (pre 964) guys and gals have understood this for years - God bless them).

Marc B. marc_b@sympatico.ca