Wandering

[high52kojak]

On roads that are not perfectly smooth, ie roads with bumps and where so many tyres have pushed the tarmac down over the years leaving slight grooves, the Cerb tends to wander/pull left or right quite a bit, doesn't fill you with confidence, especially if your shifting along. Has anybody else experienced this.
I've had new tyres and camber and tracking all sorted but its still the same.

Steering rack maybe??

[JensenA]

I think your refering to 'tramlining'? My car has all the steering geo correctly set up. On the inside (or is it the outside?) lane on Motorways - the lane all the trucks use - it wanders about all over the place, so I just go into 'Old Man in a Volvo' mode and sit in the middle lane.

[ridds]

I would say Drag link bushes or Tyre pressures too high.

Mine still tramlines even with all the front end tightened up.

[Allandwf]

It's normal with wide tyred cars, you should also find it will follow white lines. You just need to be aware.

[Brummmie]

Mines a sod for tramlining too.

[high52kojak]

Sounds pretty normal then or at least common.
Have tried pressures from 22 psi up to 30.
Bit of a pain in the arse, must look like I am pissed to cars following me.
I thought there could maybe some play in the rack, but maybe not, just part of normal Cerb running probably

[WorAl]

mine tramlines a bit, untill you get to higher speeds - you know like 40, 50 mph

Edited by WorAl on Wednesday 22 July 12:24

[T8RUS]

mine used to tramline until i changed the tyres from brigdestone S 03 over to vredestein. since then ive had no problems with tramlining at all.

[julian64]

I'm running S03's and managed to dial out a lot of the tramlining it used to have.

Not sure what finnally did it. Changing the tracking helped. Nitrons helpd a lot. Upping the front spring rates to 450 helped, and messing with front castor helped. Front camber didn't seem to do much. Problem with loose quill shaft in steering helped a lot. UJ's need to be tight. Much improved on what it was.

Quill shaft in steering is when you are stationary with the engine off and rock the steering wheel from side to side. No more than quarter inch of play till the wheel starts to move on the ground. More than that and I'm convinced bumps in the road feed back through the power steering to exaccerbate tramlining.

I had some photos of my quill in pieces and you can see what I mean.

[high52kojak]

How do you adjust the castor?
Do you still have any photos of your quill?
I am sure they shouldn't do this, if there is play in the rack then the wheels will surely follow the natural detours of the road.

[greenm]

Mine does it too, worried me to begin with but have new shock and set up its just a mixture of as said on here wide tyres, also with such a small left to right turn on the wheel it will shift a lot on a rough road but to be honest on a smotth surafce u can let go and its no problem

[julian64]

high52kojak said:

How do you adjust the castor?
Do you still have any photos of your quill?
I am sure they shouldn't do this, if there is play in the rack then the wheels will surely follow the natural detours of the road.

The castor is only adjustible with adding or subtracting shims unfortunately.

The quill is a fine metal shaft going down through the centre of the plate on the top of the steering rack into the steering rack itself. its held by a machine pin. The point of the shaft is that it twists when you move the steering wheel, and by twisting uncovers a hole to allow steering rack fluid to flow under pressure to help push the rack along in the direction you've moved the steering wheel.

The problem is that the machine pin is very tough but the metal it sits againsts is very soft, after a while the pin starts to enlarge the hole and becomes sloppy. This slop affects the way the hole is uncovered and therefore when and if the steering rack pressure is applied to the wheels. More than this, its possible to see how a sudden pressure on the wheel can make the sloppy shaft move without actually turning the wheel. Hance my worry that the sloppy quill was allowing the road to mess with the distribution of the power steering pressure.

In a normal setup the power steering does exactly the opposite by isolating you from bumps in the road, and so would the TVR if the machine pin in the quil is tight. I don't think this is the only problem, but it does seem to contribute as said above.

Much easier to see what I mean with the bits on display. Been a few years since I had mine in pieces, but I should still have the photos, but can't currently find them

[VPower]

Mine was terrible until I adjusted it to toe-in, it was toeing out that caused mine to feel very lively.

[ridds]

Yep increased castor and Toe in should help.

Agree with the steering column and quill shaft comments too, there are just toooooo many joints in that system.

[HRG.]

Allandwf said:

It's normal with wide tyred cars, you should also find it will follow white lines. You just need to be aware.

Not with a proper geo setup!

[high52kojak]

Julian how did you fix it? A new rack?

[julian64]

I put a larger machine pin in

[high52kojak]

Makes sense, until that one opens up the hole even more.
What exactly is a machine pin?

[Brummmie]

I had Bstone 225/35-18 S0 something or other on, and it was best on those, i had Pirelli P Zero 225/40-18 on, and they were the extra load sidewall Porker spec ones, and it was horrid. I backed the suspension off and let the tyres down so it was drivable, i now have Toyo 225/40-18 and they are sort of Midway. Has anyone got anything to say about 235/40-17's as i am thinking the extra sidewall depth might be a good thing.

[gcpeters]

Any joy with the pics julian?

GP