Going straight

N

Neil900

Wrench Pro
Points
21
Location
UK Birmingham
Car
Saab NG900 SE Turbo
Ok, so I've changed the front tyres, had new track rod ends fitted to enable tracking to be set up... it still pulls to nearside, what to check next???
 
turbonutter69 said:
Has it all been lined up?
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Exactly! that much in the way of suspension modifications needs a full geometry set-up done!
You will be dazzled at the results! Yes a bit more expensive but true handling performance does not come cheap - but it will be money well spent :bigsmile:
 
So a full laser alignment needs doing rather than just having the tracking set? Starting to wonder if I've landed myself with a dog! How can I check to see if its straight underneath, will a full geometry set up show up whether or not its bent, or is this a bodyshop job
 
Neil900 said:
So a full laser alignment needs doing rather than just having the tracking set? Starting to wonder if I've landed myself with a dog! How can I check to see if its straight underneath, will a full geometry set up show up whether or not its bent, or is this a bodyshop job
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Tracking only accounts for some of the parameters required for the car to produce even tyre wear. I would double check the tyre pressures all round first and try again with the braking in a straight line. Then put it in for a full alignment if there is no discernible difference. A full geometry set-up takes into account the rear and front tyre alignment, camber, caster,Toe, steer ahead and thrust angle so that the front works in harmony with the rear.
 
Check the panel gaps along each side and see if they match up. If not then chances are it has had a hard shunt.

Adverse camber can cause a car to pull to one side so do the test on a flat road.

Make sure the tyre pressures are equal across the axles.

Does it pull to one side under acceleration, braking or just when going at a set speed.
 
Can't tell what car it is on my blackberry internet but how is your rear suspension? Some cars have rear suspension that you can't adjust so if you have worn bushes for instance it can mean you never get proper alignment until you replace the worn bits.
 
It's a 1997 ng900 turbo 5door. It has had a front end knock, insides of the front wings are different colours, headlights slightly out of aim & front grille has a couple of broken clips... but apart from the slight wandering to nearside, it drives well. Has passed MoT's etc. The car came from a stable owner & caked in mud underneath & probably driven across fields etc... Just wanna get it to run straight but need to find out which part is at fault???
 
AH. To be honest if it's had a front end knock then it's likely some of the suspension components have been bent, or if it was a hard knock even the chassis. It only needs a small kink in something to screw the alignment.
 
Ah ha, now that you have mentioned a front end knock that is a different ball game altogether. For the money that it would cost, mine was £70 at my local specialist; I would put it in for a full alignment and see how far out everything is first, it could still be adjustable back into standard tolerances if your lucky.
I had a huge rivet off sorts holding the arms on the rear of my car which prevented the rear end adjustment. The specialist removed these and replace them with a high tensile nut and bolt arrangement (£40 per bolt x 2) to allow a proper adjustment of the rear suspension arms, happy days!
 
Results are...

Fronts were toeing out - been reset
Rears were 1 toeing in, 1 toeing out (basically both rears pointing to kerb slightly) - solid beam, no adjustment possible :-(
 
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Neil900 said:
Results are...

Fronts were toeing out - been reset
Rears were 1 toeing in, 1 toeing out (basically both rears pointing to keen slightly) - solid beam, no adjustment possible :-(
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It's possible to adjust the front to compensate for the rear, but like I said earlier, if you replace the rear bushes etc so it's like new, then hopefully the rears will come back to what they should be.
 
That's what I thought... but thing is, where do you stop? On a £1000 car, how much more to spend as so far its cost £150 but not made the slightest difference
 
dpends what it's worth to you really. if you want to keep it for a while then its worth it, if you're just going to have it for a year it isnt. My Bora isnt worth much but I maintain it cos I want it to last another 3 years.
 
Been thinking about this all night...

To my mind, the rear wheels pointing towards the kerb would make the car want to go away from the kerb not towards it.
When you reverse your car & want to move away from the kerb, you turn the front wheels towards the kerb to make the rears move away from it. So going forwards with front wheels straight & the rears pointing to the kerb (through worn bushes or whatever!) it should wander away not towards the kerb.
If the rears were perfectly in line, I think that would make things even worse!

Please let my know if this line of thinking is incorrect, but I'm pretty sure its not - so now what??? I am going to figure this out, even if I can't actually fix it!!!
 
Actually what about what wayne asked earlier? A general drift to the left is not unusual in cars, but a pull that is worse when you put your foot down gives more of a clue as the what the issue is.
 
wobble could be bent driveshafts, or warped brake disc, is it worse on braking? Or more likely it could be a knackered CV joint. CV joints are pretty cheap to change.
 
I could end up changing the whole front end, not a problem if cash was no object :-(

I still think its to do with front end alignment, or lack of it from a cheapo repair... just need to find somewhere that could check it for me without raping my wallet!
 
Yeah, got std. 16"alloys, tried changing front tyres, but made no difference. Thinking of measuring different points on the car to see if both sides match, dunno what else to do, don't know anyone with a bodyshop as I'm convinced the problem lies with a dodgy repair - maybe the subframe has moved???????
 
Yugguy said:
wobble could be bent driveshafts, or warped brake disc, is it worse on braking? Or more likely it could be a knackered CV joint. CV joints are pretty cheap to change.
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No not worse under braking or acceleration & CV's dont knock on full lock, either way. It did have an annoying squeak/squeal (like a loose fan belt) while driving, that went quiet when stationary, but that seems to have disappeared on it's own?
 
Who has had the wheels off? Did they make sure the spigot wheel was still inside the alloy?

Also check the wishbones on the front are all bolted up tight and the right way round.
I had an Escort Mk5 years ago and my mate put the bolts on the wrong way round and it caused havoc with the steering.
Cheapest way to check whether it is bent would be to strip the front end yourself. Your never going to notice anything unless you strip some panels.
 
On closer inspection, looks like the steering rack may of been replaced... is it possible to fit it out of line? Dunno about saab power racks, would the rack want to centre itself when powered, but if it was to one side or the other then that would run out???
Geometry checks are fine but are done stationary!
 
Steering rack mountings are an issue on the NG900. Also the bulkhead can flex whilst steering. This is why the turbo versions are notorious for torque steer problems. An after market solution is available in the form of a machined metal steering rack clamp and a bulkhead brace. These are available from Abbott Racing or partsforsaab.com
 
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