D Special rehabilitation

[ibartie]

No it's down level with the gearbox, and there's a metal bar that goes from the bracket across to the gearbox.

There is a cast aluminium bracket bolted to the steel bracket. In the aluminium bit, there is a replaceable bush. It has a cylindrical inner hole & the outer is spherical to make it work like a self aligning bearing in a pillow block.
It is Part No 31318 at Der Franzose.

 

[Greenpeace]

There is a cast aluminium bracket bolted to the steel bracket. In the aluminium bit, there is a replaceable bush. It has a cylindrical inner hole & the outer is spherical to make it work like a self aligning bearing in a pillow block.
It is Part No 31318 at Der Franzose.

OK, thank you.

 

[Greenpeace]

Well I had a measure of the toe-in this morning and it was pretty much where it was supposed to be. I have no way of measuring the camber, however by the naked eye, both tyres appear vertical, with no discernable lean. All suspension and steering components seem tight, with no play evident.
As previously mentioned, there is no apparent tyre contact with the bodywork on either side.
I decided to address the problem based on the tyre's wear evidence of too little toe-in, rather than just accepting that the toe-in measurement being in range exempted it as being causative. I turned the threaded collar one full rotation which according to the manual will increase the toe-in by 4mm.
Took the car for a spin around the local hills and and there was no doubt the steering "feel" had improved. There is one moderately high speed RH corner that I regularly go round that for whatever reason always illicits a howl from one of the front tyres (it doesn't howl anywhere else).
Today it didn't do it.
Anyhoo, at present I am running a totally incorrect 8mm of toe-in, yet as far driving the car goes, can find no logical reason to adjust it back.
Only thing I can get think of is the factory settings are best suited to the rounder profile of the OE Michelin asymmetrical tyres and perhaps they don't gel so well with a squarer profile symmetrical tyre?
I have no idea, I'm clutching at straws here, as being so far out of spec doesn't make sense on paper.
I guess all I can do for now, is keep a close eye out for signs of wear on the outside edges of the tyres.
Just as an aside, although 8mm sounds a lot I recall setting my Datsun 180B's toe-in at 12mm (the factory range is 11 to 14mm). Even better the smaller version of the 180B that we didn't get here in Aus (the 710 series) has a factory toe-in range of 14 to 17mm.
Any thoughts on the DS gentlemen?

 

[fritzelhund]

As you state you are clutching at straws..... Has the car had any "contact" with immovable objects recently ? Factory rally cars carried a long pole that could be used to RE bend the lower arm after an event. Don't even think about modifying the caster angle. To do so is beyond the capacity of a local mechanic no matter how talented. It is a total pull apart and rejig situation and in theory should never change.
You mention a threaded collar ... why adjust ONE ?
Surely a better way would be to work symmetrically from a known central position ... maybe indicated by the heart shaped cam on the steering column ... but then these are subject to movement/disassembly/reassembly too. Take no notice of the steering wheel spoke angle .. it can be anywhere as it is on a simple spline.
I recently saw a wheel alignment performed by skilled people using a chalk line drawn on the centre of the tread on the front edge of both front tyres, then the car was rolled half a wheel rotation and the centreline of the NOW front of the tyre was marked. Any variation of the track was measured by comparing the two distances. A hands on way to measure the toe in/out.
The centre point geometry and the "fake" feel of the power steering valves AND the heart shaped cam/spring loaded roller will not give an accurate seat of the pants indication. The steering relay arms can only attach in one position as they have a master spline. Having said that I have had a steering relay arm bend from over enthusiastic steering against an immovable concrete kerb.

 

[Greenpeace]

As you state you are clutching at straws..... Has the car had any "contact" with immovable objects recently ? Factory rally cars carried a long pole that could be used to RE bend the lower arm after an event. Don't even think about modifying the caster angle. To do so is beyond the capacity of a local mechanic no matter how talented. It is a total pull apart and rejig situation and in theory should never change.
You mention a threaded collar ... why adjust ONE ?
Surely a better way would be to work symmetrically from a known central position ... maybe indicated by the heart shaped cam on the steering column ... but then these are subject to movement/disassembly/reassembly too. Take no notice of the steering wheel spoke angle .. it can be anywhere as it is on a simple spline.
I recently saw a wheel alignment performed by skilled people using a chalk line drawn on the centre of the tread on the front edge of both front tyres, then the car was rolled half a wheel rotation and the centreline of the NOW front of the tyre was marked. Any variation of the track was measured by comparing the two distances. A hands on way to measure the toe in/out.
The centre point geometry and the "fake" feel of the power steering valves AND the heart shaped cam/spring loaded roller will not give an accurate seat of the pants indication. The steering relay arms can only attach in one position as they have a master spline. Having said that I have had a steering relay arm bend from over enthusiastic steering against an immovable concrete kerb.

The threaded collar on the RH side of the link between the upper relay arms is the one the factory workshop manuel says to adjust to set the toe, why would I play with any others? The one turn didn't change the steering wheel position. The vehicle hasn't struck anything during my ownership and visually both wheels sit centrally in the wheel arches.

 

[fritzelhund]

Sitting centrally in wheel arches means little. The removable and rubber mounted wings are hardly good measuring points.
My point was to work from a known straight ahead position, and measure from that known point.
The steering rack FEEL doesn't really tell you what is going on. The rack has pressure distributing valves as well as the feel inducing heart shaped cam to create an artificial straight ahead feel to the driver. The heart shaped cam's lowest point itself is not a guaranteed centre point.
You can see the entire steering column is attached to the rack assembly on a normal spline ( the single spoke on the steering wheel can go anywhere ) and the heart shaped cam's pressure roller is also able to be moved a little sideways, as can the entire rack ... That is assuming the heart shaped roller is still ON the column .. I have seen several cars with the heart cam missing.
My point was to go from a known guaranteed point on the centre line of the chassis and measure the toe symmetrically, not just adjust one side. CX drivers have a similar unreal steering "feel" with artificial centering.
The DS engine/gearbox is not symmetrically placed in the chassis, but the steering rack should be.
We are both clutching at straws.
I cannot understand why you would expect the steering wheel to have changed position with a small tweak of one steering arm.
I hope others will offer a solution.
Maybe, just maybe you have a dud tyre ? Back in the day, when Michelin tyres were hugely expensive, and often just plain unavailable locally, I experimented with a textile radial, an Olympic GT radial, ( ie not a steel braced radial ) on the front of my DS23. It didn't like the change. IIRC the Pirellis of the vintage were not steel braced either. The local Michelin importers were Boral .. of building materials fame, and whenever we wanted X pattern tyres ( 165X400 size for ID19s ) they were not available, and when we wanted XaS ( 185X15 ) they were never in stock. Cold retreads ( Bandag) were offered by Boral back then too, though were mostly in heavy truck usage.

 

[Greenpeace]

Sitting centrally in wheel arches means little. The removable and rubber mounted wings are hardly good measuring points.
My point was to work from a known straight ahead position, and measure from that known point.
The steering rack FEEL doesn't really tell you what is going on. The rack has pressure distributing valves as well as the feel inducing heart shaped cam to create an artificial straight ahead feel to the driver. The heart shaped cam's lowest point itself is not a guaranteed centre point.
You can see the entire steering column is attached to the rack assembly on a normal spline ( the single spoke on the steering wheel can go anywhere ) and the heart shaped cam's pressure roller is also able to be moved a little sideways, as can the entire rack ... That is assuming the heart shaped roller is still ON the column .. I have seen several cars with the heart cam missing.
My point was to go from a known guaranteed point on the centre line of the chassis and measure the toe symmetrically, not just adjust one side. CX drivers have a similar unreal steering "feel" with artificial centering.
The DS engine/gearbox is not symmetrically placed in the chassis, but the steering rack should be.
We are both clutching at straws.
I cannot understand why you would expect the steering wheel to have changed position with a small tweak of one steering arm.
I hope others will offer a solution.
Maybe, just maybe you have a dud tyre ? Back in the day, when Michelin tyres were hugely expensive, and often just plain unavailable locally, I experimented with a textile radial, an Olympic GT radial, ( ie not a steel braced radial ) on the front of my DS23. It didn't like the change. IIRC the Pirellis of the vintage were not steel braced either. The local Michelin importers were Boral .. of building materials fame, and whenever we wanted X pattern tyres ( 165X400 size for ID19s ) they were not available, and when we wanted XaS ( 185X15 ) they were never in stock. Cold retreads ( Bandag) were offered by Boral back then too, though were mostly in heavy truck usage.

The heart shaped cam is in position. I had no expectation that the steering wheel position would move, I only mentioned it as you had said in your first post to "take no notice of it". The car tracks straiģht and true (with hands off the wheel) both before and after the toe adjustment. The change in steering feel I mentioned is the progressive nature into corners, where the cam has no relevance. If it is a dud tyre I have two, as I said in a prior post the RH side is displaying the same type of wear, it's just not as bad as the LH side.