Torsion bar setting: 1989 CTi 1.6

[lagonda 41]

I bought my CTi back in 2003 with just a few days MoT left on it. I guess I should have been suspicious it didn't have a new MoT, given the seller worked at a garage. A couple of months later, I took it for MoT, and surprise surprise, it failed. One of the reasons was worn bearings in the rear beam. So, one of my first jobs on the car was rebuilding the rear beam. Great imaginitive design, but why such stupidly fine roller bearings, more fit for a watch than a car!

 

Anyway, I thought I'd lower the ride height whilst everything was apart; regretted that decision ever since! I know I marked the torsion bars and mountings with paint, but doubt those marks have survived 16 years. I spent a long time checking and rechecking my settings, but the result was the car sitting far too low at the back; indeed the shock absorbers are pretty well fully compressed. Even worse, I also managed to get one side lower than the other. Grrr.

 

I'm having some welding done which will necessitate removing the rear beam, so I'm hoping I can sort things out properly. If my paint marks are still visible, fine, but I suspect they won't be.

 

So, can anyone tell me how much the ride height will change per spline? I recall there were different spline counts at each end of the torsion bars, so it would be helpful to know the difference for each torsion bar end.

 

Alternatively, is there an easy way to correctly set the rear suspension, starting with everything apart and no setting marks?!

 

If it makes a difference, the car is on 1.9 wheels with 195/50x15 Toyo Proxes TR1, which I intend changing to Michelin PS3s.

 

Laurence

[Tom Fenton 1,524]

27 minutes ago, lagonda said:

Alternatively, is there an easy way to correctly set the rear suspension, starting with everything apart and no setting marks?!

Yes, you hold the trailing arm in a fixed position using what some call a dummy damper between the damper bolts. In its simplest form a piece of flat bar or even batten wood with two holes drilled will suffice. With the arm supported rotate the torsion bar until it’s a nice slide fit into the splines at both ends. Due to the unequal splines you mention the bar will at some position fit well. Do one side then move the support to the other and repeat.

Suggest 325mm centres for standard or 312mm to suit 30mm lowering springs.

 

[lagonda 41]

Hi Tom,

 

  That's great, many thanks. I did grease all splines back in 2003, so hope I'll be rewarded with relatively easy dismantling. If I hit problems, are you still able to supply your torsion bar tool?

 

Laurence