Caster Angle

[alane]

I took my car in to local tyre dealer who have a Corghi laser 4 wheel alignment machine. They've corrected the alignment but the machine shows that the caster angle is out by some margin. They don't think this is adjustable. The car is still pulling to the left - is this a likely cause and is there any way to adjust caster angle?

 

I've done a search on the forum but apart from the odd mention, caster angle doesn't seem to have featured in any other threads.

 

Best Regards

[gregers]

friend of mine had this problem,he took it to a dealer and they pretty much said the same thing.

[chrispb123456]

Hi Alane

You haven't mentioned anything about the tyres.

If the shoulder of your tyres are worn especially the N/S/F your car will constantly pull to the N/S this is compounded as well by the camber of the road.

The most common reason for tyre wear is under inflation.

Steering geometry doesn't alter on it's own, if the settings are wrong there is usually a worn joint or bush, or damage to the suspension

[alane]

Thanks for the ideas here.

 

The tyres are only a few weeks old and when mounted I had the geometry checked and all readings were green. Since then it's had new drive shafts and clutch so some disturbance to the overall setup I assume (I'm not sure exactly what has to be disconnected to get the clutch out).

 

The caster has gone from +3.3 deg identical both sides to +4.23LH and +1.08RH. Spec is +3.2 +-1.4deg.

 

I've tried it on a reverse camber and it still pulls to the left although not so bad. It's going back into the garage so I'll ask them but if the settings aren't adjustable then that might be a problem.

 

Thanks.

[insider]

Your problem is not just that the LH reading is out of spec. but that the difference between the two is also greater than 1 deg. This 3.15 deg difference is what's causing it to pull to one side.

 

The spec. is actually 3deg 20' +/- 0deg 40' (in decimal terms 3.33 +/- 0.67) with no greater than 1deg difference between left and right. So, even if the left was at top spec. (4 deg) and the right was at bottom spec. (2.67 deg) the whole would be out of spec. as there would be a 1.33 deg difference.

 

The caster angle is effectively set by the suspension geometry, i.e. the position of the balljoints in the upper and lower suspension arms. For this to have changed something must have been damaged, perhaps during the driveshaft/clutch work?

[alane]

[OK Thanks.

 

So it looks like there must be some damage somewhere or the readout is wrong. The garage that changed the clutch has been very good over the years and is run by a couple of real enthusiasts so I'll be surprised if they've caused any damage. Maybe this is another in the long line of faults in the car that I thought was a bargain a couple of months ago..............

 

Best regards

 

Alan

[sparky Paul]

So it looks like there must be some damage somewhere or the readout is wrong. The garage that changed the clutch has been very good over the years and is run by a couple of real enthusiasts so I'll be surprised if they've caused any damage. Maybe this is another in the long line of faults in the car that I thought was a bargain a couple of months ago..............

 

The front suspension on the Galaxy is pretty robust, so you could be right thinking that the damage could have been pre-existing. I doubt the clutch work could have caused any problems, they shouldn't need to drop the front crossmember, and in any case special alignment tools for refitting are not required, like on the Mondeo front subframe for example.

 

It's probably worth a second opinion, just to make sure that the castor figures tally.

 

The good news is that if the suspension has been damaged, the most likely is probably a bent bottom control arm or split bush, and complete replacement bottom arms are available relatively cheaply. If it gets really serious and the front crossmember is also damaged, it should be possible to find a good replacement from a breaker.

 

Hope this helps. :lol:

Edited May 27, 2010 by sparky Paul

[alane]

So it looks like there must be some damage somewhere or the readout is wrong. The garage that changed the clutch has been very good over the years and is run by a couple of real enthusiasts so I'll be surprised if they've caused any damage. Maybe this is another in the long line of faults in the car that I thought was a bargain a couple of months ago..............

 

The front suspension on the Galaxy is pretty robust, so you could be right thinking that the damage could have been pre-existing. I doubt the clutch work could have caused any problems, they shouldn't need to drop the front crossmember, and in any case special alignment tools for refitting are not required, like on the Mondeo front subframe for example.

 

It's probably worth a second opinion, just to make sure that the castor figures tally.

 

The good news is that if the suspension has been damaged, the most likely is probably a bent bottom control arm or split bush, and complete replacement bottom arms are available relatively cheaply. If it gets really serious and the front crossmember is also damaged, it should be possible to find a good replacement from a breaker.

 

Hope this helps. :)

 

Paul

 

Thanks for the advice, sorry not to have responded sooner but I've been away for a long weekend. Car seems reasonably ok just pulling to the left a bit. I'll take it to another garage for a check as you suggest. The garage that did the clutch work don't think there is any problem but then after making just a few quid out of standard servicing on my old 98 Sharan with 260k miles on the clock they are probably planning early retirement on the money coming in from me on repairs to this Galaxy.

 

Best Regards

 

Alan

[chrispb123456]

Hi Alan

Have you re checked tyre pressures since you had them fitted? even a small underinflation especially N/S/Front wheel will steer/pull towards kerb.

[alane]

Hi Alan

Have you re checked tyre pressures since you had them fitted? even a small underinflation especially N/S/Front wheel will steer/pull towards kerb.

 

Hi Chris

 

No, pressures are ok. I check them regularly, but thanks for the suggestion anyway. A bit of a mystery as the caster angle was ok when checked end of March. I've not had time to look at it or get it into a garage since getting back but will try this week.

 

Best Regards

 

Alan.

[daddyfixit]

Hi Alan

Have you re checked tyre pressures since you had them fitted? even a small underinflation especially N/S/Front wheel will steer/pull towards kerb.

 

Hi Chris

 

No, pressures are ok. I check them regularly, but thanks for the suggestion anyway. A bit of a mystery as the caster angle was ok when checked end of March. I've not had time to look at it or get it into a garage since getting back but will try this week.

 

Best Regards

 

Alan.

 

old fashioned remedy; swap the 2 front wheels with each other, if n/s tyre has worn conical it will carry on wearing conical, putting it onto opposite side of car will in effect, pull car to the offside, or in a straight line. once a tyre has started going conical it wont stop wearing conical (common sense)

 

costs nothing except time taken for you to swop both front wheels.

[Willie Krashitt]

Just a thought - you haven't got a slightly binding brake on the left hand side? Front or rear, If you have, it will make it pull to the left. Easy to check if you have the wheels off swapping tyres over.

 

George.