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

[Philip410]

I have a 410, stated clearance 6.5", the car has new front springs Konis and spring spacers. It is shod with Cinturato205VR15 which according to Longstones have an inflated dia. 0.6" greater than the OE Avon 670x15. The unloaded clearance is 5.75". Not sure on what the 6.5" is based.

[dwomby]

Originally Posted by Philip410

I have a 410, stated clearance 6.5", the car has new front springs Konis and spring spacers. It is shod with Cinturato205VR15 which according to Longstones have an inflated dia. 0.6" greater than the OE Avon 670x15. The unloaded clearance is 5.75". Not sure on what the 6.5" is based.

THANK YOU!

That's rather reassuring!

David

[Kevin H]

Originally Posted by Philip410

Not sure on what the 6.5" is based.

Pretty sure it's the distance between the bottom of the front crossmember and the road.

[dwomby]

More on ground clearance. I found this brochure for the 411 S1

https://www.veikl.com/d/Bristol-411-...969-EN-46747/7

It states ground clearance 5". I wonder if Bristol lowered the clearance that much v. the clearance quoted for earlier V8s? Especially as the silencers seem to be very vulnerable to grounding going over a hump? Maybe they changed the point of measurement and this brochure measures from ground to bottom of silencers?

David

[Kevin H]

Originally Posted by dwomby

Maybe they changed the point of measurement and this brochure measures from ground to bottom of silencers?

Brian Marelli (head of Bristol Cars Services) told me the ground clearance measurement was between the bottom of the front crossmember and the road.

PS. That said, I was asking about my 411 S5. Perhaps it was measured differently on the earlier V8 cars?

[dwomby]

Originally Posted by Kevin H

Brian Marelli (head of Bristol Cars Services) told me the ground clearance measurement was between the bottom of the front crossmember and the road.

PS. That said, I was asking about my 411 S5. Perhaps it was measured differently on the earlier V8 cars?

Yes, I remember you were told that. I think they must have shifted the reference point from the crossmember to the silencers in the 411 S1 brochure they published.

David