Torsion bar bush replacement

[Bruceynz]

My thoughts are this - if your driving a long a smooth road there are no issues what so ever, the amount of movement will be minimal and even under extreme travel I really have no idea how much it moves, I would have to measure stuff and then use some form of trigonometry that I forget how to use now so for me I can go no further as far as to say my car seems to drive ok

 

[BudW]

I agree on the fact that "things appear to be a possible issue" but, in this case, I wouldn't overthink it. It has worked fine for decades for us.

 

[AJ/FormS]

If you set the LCA in the right spot in the alignment window, then, as the LCA cycles up AND down, it will be pulled forward, possibly pushed rearward, by the cycling L-bars. This changes the caster/camber. In any case, it isn't much, and usually only one side atta time is doing the dance. If the toe is set pretty close, the car will seem to steer "pretty good"...... lol.

 

[kkritsilas]

Have you guys ever looked at the suspension and what is wrong with it?? The torsion bar is connected to the bottom of the arm, then come out towards front of the car where it is connected with this bushing, this is a pivot point, as the wheel goes up and down through and arc that torsion bar is relying on the play in the bushes to move up and down. Its a poor design! the cars with parallel bars never has this problem. Anyone like to help me out if I am right or wrong here, I am no suspension expert.

View attachment 35079

You are correct in your thinking, as far as it goes. However, your diagram is a much more extreme case than what the real world. The suspension works fine, for STREET use, which is what the suspension was design for. The original intent for the "transverse torsion bar" suspension was to duplicate the ride of the "Big Cars" (B, C, and R bodies). Great handling was less of a consideration. All that being said, this suspension design was used in tens, if not hundreds of thousands of police cars, without the suspension geometry being an issue.

 

[kkritsilas]

Have you guys ever looked at the suspension and what is wrong with it?? The torsion bar is connected to the bottom of the arm, then come out towards front of the car where it is connected with this bushing, this is a pivot point, as the wheel goes up and down through and arc that torsion bar is relying on the play in the bushes to move up and down. Its a poor design! the cars with parallel bars never has this problem. Anyone like to help me out if I am right or wrong here, I am no suspension expert.

View attachment 35079

All suspensions, of all designs, have elements that pivot around one or more pivots. To a greater or lesser degree, all have camber, caster, and wheelbase changes. Unless sliding joints are incorporated, all that can be done is to allow the movement to result in the changes to be minimized to the extent possible within the space allocated.

The transverse torsion bar suspension was designed to give smaller cars, a "Big Car" ride (B, C, and R). Handling wasn't as big a consideration. The suspension doesn't have a great caster/camber curve. However, it works just fine, as tens, if not hundreds of thousand of police cars have proven. The design works fine, with the prime characteristic being met, and taking up a minimal amount of space (important for a smaller car).

 

[Bruceynz]

I got a lot to caster on my car, I think in the order or 4.5 - 5 degrees, factory spec something like 1.8 to 2 I think, was quite low. If you have watched some of my other posts with help from people on here I have just about screwed and twisted every bolt and part on my car to get it to drive good. I was driving it the other day and I surprised myself how well it drives now! My car is so far from stock now! It just looks stock but it's not.

 

[kkritsilas]

More caster than factory spec is actually a good thing. The factory caster spec. is a little low. An added 1-2 degrees of caster is fine, and the car's steering will feel better.

 

[Bruceynz]

Well I didn't replace, I cut the rotten bit off, bought a 32mm ID PVC water fitting, slit it, heated it in boiling water put over torsion bar and add a bit of gunk to seal it up. That should see a turn out of it until I get around to feeling energetic to replace.

 

[Bruceynz]

I run a lot of caster, heavier front sway bar, added rear sway bar, FF upper control arms with more caster, wider tires, steering gear with 4 reaction springs fitted, machined and bearings fitted to sector shaft, solid body isolators, poly spings pads in the isoclamps.

 

[Bruceynz]

Ok I found the alignment sheet, factory spec 1 - 2.5 degrees, my car is at left 5.07 degrees and right 5.01 degrees. Camber -0.45 degrees and toe was set at 3.7mm total, not sure why that was, thought 0 toe would of been best.