408: rear suspension adjustment. What is the procedure?

[dwomby]

My car has a very slight but noticeable tilt down on the driver side. I see from Dr Pasini's site that in addition to removing and refitting the torsion bar for major adjustment, there is an adjustment screw. It's shown in the parts manual and near the foot of this page: The engine of the 409 being rebuilt in Bologna.

I can't find a description in any of the online manuals for how to do this adjustment. Can anybody describe the procedure, please?

David

[Kevin H]

David,
Is the tilt even at the front and rear of the driver's side of the car? (in other words has the front and rear dropped to the same extent).


Kevin

[dwomby]

Originally Posted by Kevin H

David,
Is the tilt even at the front and rear of the driver's side of the car? (in other words has the front and rear dropped to the same extent).

Kevin,

OK. I need to get the car on the flat outside and take a good look and some measurements. It won't be today as we expect rain.

David

[Kevin H]

David,
I should explain why I am asking. There is a part which Bristol called a "distance piece" which sits above the front coil spring. I don't know what the original ones were made of, but they disintegrate over time and if one side goes before the other it would make that front corner of the car drop slightly. It is part No.10 in this diagram. The lower "spring seat" part No.15 is made of the same material and also eventually disintegrates.

You can see the new versions of these parts, (purchased from Bristol), in this thread . You may notice there is also a black rubber piece in the picture in that thread - I believe that was added on the 411, but would be worthwhile adding to the 408 if you need to refurbish the front suspension.

Kevin

PS: Re-reading my old thread on this topic, it was actually the steel plate between the rubber and the distance piece that was a later addition, not the rubber piece.

[dwomby]

Thanks, Kevin. Very interesting. My old XJ6 had large flat rings in the front spring pans too. They were used to adjust ride height but were plain, flat rings. Nothing like the complex shapes shown in the thread you reference.

I'll update when I get to examine the car. Hopefully tomorrow.

David

[dwomby]

Is there anything specifies how to measure ride height on a 408, etc.. For example, On a Jaguar XJ6 the factory manual gives the measurement when fully laden from the ground to the center of the main headlight.

Thanks
David

[Kevin H]

Originally Posted by dwomby

Is there anything specifies how to measure ride height on a 408, etc.. For example, On a Jaguar XJ6 the factory manual gives the measurement when fully laden from the ground to the center of the main headlight.

On the 408Mk1(up to chassis 408/7200) the unladen ground clearance was specified as 6.5 inches.

When I previously discussed ground clearance of a 411 with Brian Marelli at Bristol Car Services, he said it was measured between the bottom of the front crossmember and the road. I can only assume the measurement on a 408 would be the same. However, no matter where it is measured from, wheel diameter, tyre size and tyre inflation will affect that measurement.

David, what you really need to know initially is whether the body of the car is at the same height at each wheel. I was thinking perhaps you could measure the distance from the upper chrome side trim to the ground at each end of the strip on each side of the car.


Kevin

[dwomby]

Thanks, Kevin. I'll check to bottom of the crossbar today. Meanwhile a quick run out to the car with a measuring stick came up with the following:

Front: ground to bottom of lower chrome strip passing through center of hub cap - right side is 3/8" lower than left.

Rear: ground to bottom of chrome strip passing through center of hub cap - right side is 1/4" lower than left.

I'll recheck later today.

David