Front Suspension Setup

[c7trp]

I'm a Newbie 7 owner, and so some this may be complete 🙆🏻, as I don't have experience of other 7's. (Sorry this goes on a bit)

 

The car is very unstable at high speeds (>60mph)and the steering is heavy. If at you turn into a bend, at any speed, the steering lock stays at that angle until I turn it back straight again - it doesn't 'roll off' lock like a tin top does.

 

I've adjusted the toe from 2deg toe out 😳 to 20' toe in and adjusted the camber to -1deg 20'

 

This has made a vast improvement, you can now let go of the wheel to change gear on a bumpy road 😬

 

However the car is still twitchy, especially on bumpy roads.

 

The track rods are about 6mm out of parallel with the lower wish bones, so I think I need to shim the rack as per the LF article for bump steer.

 

But the lower wishbones don't have the washer configuration specified in the manual. There is only one, c4mm thick, washer on the rear side of the bushes - pushing the wishbone as far forward as it can go.

 

I assume this is wrong, minimising the castor angle. Is this is what is making the steering heavy?

 

Should the washers be 'normal' (1 mm thick ish) washers to suit the bolts?

 

Or am I just being a wimp 😳 😬

 

 

[Shaun_E]

If the wishbone is as far forward as it can go then the castor angle is probably too large. See my post here for some more information.

Tyres and spring/damper rates can also affect bumpy road performance. I ran A048Rs for a while and these tramlined pretty badly and were poor on very bumpy roads. I switched to CR500s which are a lighter tyre and the ride improved a lot.

Bump steer can be dialled out as described in the LF article and that will almost certainly help.

Finally, adding a bit more toe in will also help at the expense of turn in on smooth surfaces.

 

Yellow SL #32

[6speedmanual]

Hi Tim

 

It would be worth checking the castor angle aswell as the other things you've done.

 

There are normally two thick, large diameter washers on each lower wishbone bush. They can be distributed infront or behind the bush. Putting washers behind the bush (move lower wishbone forwards) increases castor. Each washer is worth about 0.6 degrees.

 

Normal castor range to work with is around 4 to 6 degrees. In theory, more castor gives heavier steering loads, more self centring and possibly a tad more mid corner grip in turns. Unequal castor will make the car drift or drag to one side and maybe more so under braking.

 

Having said that, I would not expect the car to feel as if the steering is sticking on lock or have an unwillingness to straighten up. Also check that there is nothing seized in the steering mechanism eg: a ball joint or the rack itself could be sticking. The rack can be adjusted with the big thrust nut over the pinion. If rack is bent, need a new rack.

 

Although one can identify an individual suspension parameter which may be "out" of spec, ultimately the set up must be regarded as a whole, giving consideration to all the variables together, but that is fine tuning once you've overcome what sounds like a problem/fault.

 

Hope this gives you some steer on the subject (boom, boom - no cheesey pun intended)

 

Post on how you get on. Good Luck

 

 

 

 

 

6SpeedManual

*tongue*There's no such thing as too much BHP per Ton 😬

[c7trp]

Thanks all.

 

I'll jack it up at the weekend and see how it feels with no load on it. I assume this will show any tightness in the rack or ball joints.

 

Make sure everything is OK mechanically before I worry about the setup.

 

 

Edited by - Tim Pollard on 15 Mar 2007 09:23:01

[alextangent]

I've just had a similar problem of stiff steering (which was fixed with some grease/oil mixture on the steering rack end of the track rod; it was as dry as a dingo's jockstrap ).

 

The ball joints at the end of the track rods should be tight; you may find it difficult to impossible to twist them by hand. If they're easy to twist and have any play at all (try pulling them up & down, side to side and feel for knocks), they need replaced. With the front jacked up, you should be able to turn the road wheels by hand without any undue problem without any knocking or tight spots, and it should be the same from the steering wheel end; just a smooth progression with no backlash.

 

Best of luck

 

 

 

Alex McDonald

A loud 1700 SS

[Paul McKenzie]

Alex,

 

The correct Aussie measure of dryness (after Barry MacKenzie, Private Eye, 1960's) is in fact "dry as a dead dingo's donger"

 

Paul

[alextangent]

Ah, the joys of Aussie speak. My favourite Bazza-ism was the "technicolour yawn" 😬 😬

 

Added; you aren't related to the said chunder wonder are you 🤔

 

Alex McDonald

A loud 1700 SS

 

Edited by - alextangent on 15 Mar 2007 10:21:27

[c7trp]

G'day

 

Anyone know how thick the standard washers are?twang>

[alextangent]

The same as are on it currently; there should be at least one washer there iirc.

 

Alex McDonald

A loud 1700 SS

[c7trp]

Yeah, current washer is approx 4mm thick.

 

Are the 'proper' ones normal washers, or are they thicker?