Incorrect toe (in or out) will not affect steering pull to any appreciable degree. For instance: it you dial in 1/8" toe-in all on one side, which is not the correct way to do it, then that wheel has too much toe relative to car center line. If you purposely held the steering wheel rigid, the car would “pull” (actually being pushed) to the side with the least toe, relative to center line. But that’s not how the car rolls down the highway, the wheels will naturally align themselves until equal scrub force between the two wheels is achieved. Too much or little toe will affect cornering and make the steering feel “dead” or “twitchy”. And as you all have said, inner or outer tire wear will be obvious.
Add road camber to wrong toe, and the car will pull - and road camber is a common feature on most roads.
As comment to the original post; the suspension is specifically designed to minimize wheel camber changes with suspension movement - so ride height has little influence on camber settings…within reason. Nor on castor or toe - after all; large geometric changes with suspension travel is not conducive to predictable car behavior…
Frank, my post was addressing your post to Aristides where he said that “wrong toe-in will not cause a pull”. I kept my response to toe settings because that seemed to be the point you were making. Of course camber and castor affect pull as well as road crown (camber), tire pressure, mismatched tire types, different tire brands on the front, bias/radial tires on the front, and more.
Yes, road crown will affect most car/trucks by making them drift to the low side, usually the right. The large trailers used all over the world to transport freight have the rear axles canted very, very slightly toward the road center line just to counter act road crown. But toe setting is not the reason or cure for this, a slight adjustment to the caster setting will help cancel this effect, its called “cross caster”. Camber will also create a tendency to pull towards the side with the most positive camber.
I agree that cars are designed to provide acceptable steering and ride from the front suspension geometry, but they cannot afford to make that geometry precise, as in a race car for example. Have you ever noticed how the front tire (usually the outer) of your car scrubs or maybe even squeals a little when you turn sharply into a parking spot? That is commonly caused by incorrect “Ackermann” which is the geometry that allows the inside tire and the outside tire travel in a different arc around a common point when the steering is turned. It involves chassis/steering engineering that just isn’t appreciated or known by most car owners and everyone is used to their tire(s) scrubbing when they park and run in for groceries. There is another idiosyncrasy of front steering geometry called “bump steer”. Caused by the lower A-arm and tie rod not being in the same plane and not pivoting around the same axis. Common in most cars, I would suspect, but not something most car owners should be concerned about. And ride height does affect the handling of your car if you get very far from stock, just ask anyone with one of those jacked up 4x4 pickups how his steering is. But as you’ve said, minimal effect very near stock settings.
I’ll end with a comment to one of your posts to Adam Thompson, “that doesn’t matter, Adam, the alignment shop knows it all-what they need are the numbers”. If the shop doesn’t have the correct alignment specs for your car, they certainly do need them, but a shop that doesn’t know that caster is set by shims at the upper out board ball joint and that camber is set with the shims (evenly removed/added) at the upper inboard A-arm attachment can’t give you a good alignment. That’s why I prefer someone who has some experience with Classic Jaguars do the work. Or learn how yourself.
I second it all, Dave - couldn’t have said it better myself…
The point is that we have the Jaguars as they are, and their specs as given. Which doesn’t mean that they are perfect - they are compromises. Any odds that rectifying his toe will remove the pulling - though admittedly; if the castor angle has been tweaked for ‘left’ side driving and he is driving on the ‘right’, or vice versa - it will cause pull…
But even if cumbersome to adjust; an alignment shop should at least be able to measure toe - to confirm or refute that as a factor…
I don’t have any new or better info on the VIN break beyond what is already mentioned in your document from a few years ago.
It seems obvious to me that the later alignment specs are intended to coincide with the control arm change but that break point is unclear, with 360xxx and 354xxx both being mentioned in Jaguar literature
I’ll try to find the TSB again, but it might be awhile !
We are on the same page Frank, and you make a point as to which side of the road you drive on. Also would be a consideration when on a 4-lane road; cross-caster set for 1-lane or right side of 2-lane and when you pull over into the left lane, the car drifts to the left a little, return to the right lane and everything is fine. As you said, 'have to understand the compromises, nothing is perfect.
And all specs are expressed in terms of an acceptable range. Not a single precise, go/no go point.
My opinion and experience is that these old Jags are tolerant; they’ll steer and behave well without extraordinary efforts by the alignment shop. It’s not magic. The specs themselves, although obviously required, are pretty typical of lots of RWD cars; not exotic or unusual. If an experienced alignment guy didn’t have the specs he could probably get an acceptable result by following his nose, so to speak.
The adjustments can be fussed over, by a dedicated alignment guy, for optimal results and/or compensate for certain conditions (road crown for example). You probably won’t get this kind of attention at a high-volume, franchise type tire shop where their mission is to bang out 12 alignments per day, every day, at the advertised $59.95 ‘special price’.
Cheers
DD
Aside, many many years ago I took my (non-Jaguar) car in for an alignment. When picking the car up the guy spoke with me and said that he took notice of my added rear sway bar, upgraded bushings, performance shocks and tires, and such. He said “I took some liberties with the specs and made some tweaks that’ll work well with your set-up. I think you’ll be very happy”. And I was I was very pleased that he used his brain and experienced to suit the situation at hand.
I agree Doug, experience and dedication are key to a job well done, no matter what that “job” might be. As you say in your ending “aside”, “many, many years ago…and I was very pleased that he used his brain and experience to suit the situation at hand”. My experience has found this harder to come by.
A lot of shops have a pre-conceived notion that everything on a Jaguar is arcane and problematic.
Which is why I recommend shops accustomed to dealing with unusual cars, hot rods, etc. They’re not put-off by seeing something beyond the everyday Hondas, Toyotas, and F150s.
Thanks Doug. I have seen a couple of classic Jaguar’s on the roads here on nice sunny days. I’ll try to find out if there is a Jaguar Club anywhere around my area. Your suggestion has legs.
