Another caster question

[Peter Cripps]

I’ve noticed that my Fulvia pulls very slightly to the right – really only noticeable when you take your hands off the steering wheel, but still …

I checked caster the other day, and found that the RH front wheel, that is, the passenger side on a left-hand drive car, has virtually zero caster. I determined this by observing the change in camber angle as I moved the steering from 1 turn left to 1 turn right. The LH wheel does have some positive caster, can’t say exactly how much since I’m not making a direct measurement.

I believe that mismatched caster could account for the slight pull, but then the question is why …

So I placed a spirit level up against the subframe flange, just under where the large front suspension castings are located. Sure enough, on the LH side, I measured approx 2 degrees slope, but only 1 degree on the RH side. Now, 1 degree doesn’t sound very much, but 1 degree in caster difference could perhaps cause the slight pull that I have. Also, 1 degree over, say, 50 cm, amounts to almost 1 cm, quite noticeable.

I’m thinking this could also explain why I see this on the passenger side:



Does this mean that I have a twisted subframe? And what can I do about it?

(Maybe just forget and be happy!)

Thanks,

Peter

[Brian Long]

Peter and others,

I know I am probably piggy-backing on the Fulvia front suspension topics;but seeing as the Flavia front suspension is similar and this topic hasn't been raised in that model's forum, can anyone advise what, if any, camber adjustment there may be in the Fulvia ( and hence the Flavia's) front suspension?
The Flaminias had a beautifully expensive eccentric bush adjustment.

Brian Long

[P. de R. Leclercq]

Fascinating - I congratulate you on your perspicacity.

Mind you almost every Fulvia I have worked on seems to have the twist shown.

On my own car I have replaced the rubbers with aluminium mounts with ball races and I do not have any problem (despite rather a lot of sub-frame"mods".)

I have often thought that the rubber has to put up with some terrible stresses in its working life and imagined that these may be the cause for some of the distortion.

Paul

[Peter Cripps]

Paul, thank you -- I think!

Actually, you are the second person to tell me that 'they are all like that, sir', regarding the rubber buffers. So I'll stop worrying about it. Not that I was worrying all that much ....

I should probably stop thinking about the caster as well. Tire wear seems to be quite even, and the pull to the right is really very slight. The best answer is probably not to ttake my hands off the wheel while I'm driving along!

Peter

[P. de R. Leclercq]

I think that of course a Fulvia should drive absolutely straight, but I suppose allowances must be made for thirty-odd years' use.

With the combination of a detachable subframe mounted on rubber, a bodyshell that is very weak when the subframe is not attached, and a front spring also on rubbers, it is hardly surprising that there may be a little mis-alignment.

The only solution would be to put the shell and subframe on a jig!

Paul

[Peter Cripps]

Follow-up ... in case anyone's interested!

I noticed that the RH front tire had noticeably less tread than the LH front -- both worn evenly, but one much more than the other. So, just in case, I swapped LH and RH wheels. Ha! Pulls slightly to the left, rather than slightly to the right!

Checked tread on all the other tires, and swapped them around so I had two matching ones on the front. Now the car tracks dead straight. No pull either way.

Moral of the story is to check the simple stuff first!

Peter

[shaun pond]

Peter, thanks for the follow-up!

So, why did the tires on your car have different wear levels?

Had a previous owner perhaps rotated the wheels in some odd diagonal sequence?

I've noticed on mine that the front tires seem to wear faster than the rears, so I've just swapped the fronts and the rears, but kept them on the same relative side of the car.

Regards - Shaun Pond
67 Fulvia Coupe Rallye 1.3
Benicia, California

[P. de R. Leclercq]

>
> I've noticed on mine that the front tires seem to wear faster
> than the rears, so I've just swapped the fronts and the
> rears, but kept them on the same relative side of the car.

This is normal of course on front-wheel-drive vehicles, and of course more noticeable than wear diffeences on rear-wheel-drive ones, because the front wheels have to both provide traction and steering.

Paul

[Peter Cripps]

Shaun,

I'm sure one of the POs moved the tires around for some reason. Maybe a tire shop 'rotated' them? Anyway, as Paul says, FWD cars use up their front tires much faster than RWD. When I used to drive Minis, fronts only lasted about 10k miles. Admittedly this was with 'enthusiastic' driving.

Of course I never drive my Fulvia that way. (Ahem!)

Peter

[shaun pond]

Peter, thanks to you and Paul for the information.

Henceforth, I will be able to blame the FWD for the rapid tire wear, rather than my driving.

Regards - Shaun