True, no matter the type of suspension.
Unless the car itself is bent. 
Dog tracking is easy enough to identify without help. Find a level vacant parking lot, preferably slick asphalt and wait for a rain shower. Drive in a straight line and observe the tire marks on the wet pavement. Works for all but the smallest amounts
Here in Arizona I’ve been waiting in that parking lot for more than 6 months…
-David
2 Likes
best (only) way to properly check rear drum brake adjustments too
lock them up, see if it skids sideways or locks the rears first (head out the window)
I cannot understand how a toe & camber adjustment could be in spec without full weight of vehicle resting on tyres
It can’t.
If a specific suspension loading wasn’t important why would Jaguar have specified setting links of a specific length be installed before starting alignment.
John,
Don’t you mean "It can", rather than “It can’t”? If, as you suggest, you install a setting link to replicate the position of the suspension when it’s fully loaded, you don’t need the car sitting on the tyres at all. The only thing that matters is the suspension geometry when measurements are made. On this basis, one simple way of determining if Mich’s method is valid, is to measure the distance between the ends of the shock absorber when he has it set up for his measurements. If it is very close to the same distance as when the car is loaded on the ground, the test is valid. Otherwise, there will be some error. How much of an error, is more difficult to determine…
-David
Agreed. But with most cars IMHO, supporting the corner weight on or near the upright won’t compress the springs/shocks enough. The geometry is such that the wheel travels more than the shock or coil spring (if present). There is leverage.
Interesting…some years ago, I tried to purchase of a fella a special long link he had made for some aspect of setting MKX/420G geometry, as I know the FSM refers to this…however, I just checked, and it is not mentioned in FSM for setting camber or caster…they say set vehicles on tyres.
I know for a measurable fact that when compressive force is exerted on the spring in situ, it pushes out sideways
that is why i cannot see how it can be dead accurate, unless the exact weight is on the tyres
I’m saying it can’t without the full weight of the vehicle on the tires.
The setting links set the suspension at the mid laden position. That’s more compressed than an empty car. Jaguar says install the links and do the alignment. Many people ignore that; who drives around at the mid laden position?
As an experiment I checked my camber with the car on the floor, 0.5 neg. Then I jacked the front end up and let the suspension droop to the limit of the shocks, camber 0.0
The closer you get to compressing the suspension to an at rest geometry the better.
We are not trying to be specific here…just trying to get max camber then match other side… Camber changes with weight but stays relative to each other/side…or the steering wheel would push and pull as the weight on the front changed with bumps…it does not matter to be full laden.
Jerry,
Who spent time tracking (racing his coupe) said, “get as much negative camber as you can” … and the conversation…repeated many times was…"you cannot get enough because the construction of the E does not allow it…
He went on to say…that radials love “negative camber”
All one is looking for is the max negative (inward tilt of the top of the tire) camber that the front suspension allows…then setting the other side the same…because I always find one side will allow more then the other…
Like Peter said, on the overdrive, “you’re wasting your money”…“Mitch all can spend your money as you choose”…but this gets the job done as I have seen it a 100 times…
I challenge one and all…one thinks, after spending 100’s of dollars…that the machine and guy got it right…
OK OK…go out to the garage and see what money got…doesn’t take long…jack car up on picture frame(with wood) set on jacks as far out as you can…remove wheels…vice clamp to rotors something straight out some 8 feet…now measure the toe…report back…it will not be accurate…
If the toe is NOT accurate then what does one think about camber…now pull the bonnet…set max camber, as Jerry said…set the other side equal…now you know…that is the ticket
I will report back…as the bonnet is off my 2+2…just need to go to the metal store buy a 20 foot section of 1/2X1/2 square tubing…cost about $10…take my hacksaw cut it in 1/2 in the parking lot…stick it in the passenger seat sticking up…probable use my spitfire…
Thx Mitch for your posts
I do use a 12ft long aluminium channel like you, for setting toe on various vehicles,
but just cheat and go front to back tyres
2 facing forward would be a good double check
…or just a strip of tape on centre of tyres, measure across, roll forward 180*…dead accurate, so easy
the tyres are the thing in contact with road, so i am satisfied to use them as toe, but DO use a dial gauge to check runout, in case they are bad in that respect
there was a guy not long ago, posted his excellent toe/camber gauge, mainly plumbers pipe, I may make one
after an IFS rebuild, I set basic , took it to my regular tyre shop for alignment…you would not believe the mess they made out of it…and they even have an experienced Jag mechanic
hence my interest
If things are not right tyre wear becomes apparent
On this, we agree…
Paul,
You should…you are the one…after racing around with Jerry said, “your the man” look it up…may Jerry live on
John,
I think we may be agreeing, but it seems that you don’t. I am saying that there is more than one way of getting the suspension into the loaded position. One is to just have the car sit on it’s tyres on a flat level surface. Another is to artificially hold the suspension in the same position, for example with a setting link of the appropriate length. A third is to support the car on (say) the balljoint at the bottom of the upright and then add extra weight to the cabin or wherever (40lb bags of softener salt is what I used during my restoration to get the car at the right height to tighten my suspension bushings) to get the ride height to match running ride height:
I agree with you, Robert and Tony that the suspension must be in the loaded position to accurately set the toe, caster and camber. That is not under debate. I also agree that supporting the car on the end of the uprights is not going to be accurate, as the suspension will be less compressed than when on the tyres. Mitch seems to think it is close enough, but I’m not convinced. It will also be more difficult to get the car to “sit down” as low as it should because the supporting jacks will resist sideways movement. All that I’m saying is that if you can get the suspension into the exact same position as it is when it is sitting on it’s tyres, then all your measurements will be accurate. Where I like Mitch’s approach is that if you can do this with the wheels off, his approach of using the disc rotors as a datum has more potential of being accurate than picking up on three points of the rim of the wire wheel. Now do we agree, or am I still missing something?
-David
Close enough…David…AGREE
No, we agree. Any way you can get the suspension components in the proper orientation to one another will accomplish the same thing.
If I was going to take the bonnet and wheels off I’d first make a setting link that holds the suspension in the normal sitting position, which is a bit higher than mid-laden. Install that link and then pull the bonnet and wheels. That way whatever was set would be identical to what you would see with the bonnet and wheels on and on the floor.
No we agree. It’s a matter of preferences. Unlike Mitch, I’ve found a shop I trust that does good work. I prefer to leave the wheels and bonnet on, he doesn’t. It’s that simple.
Nor am I. My feeling is if you are going to all the trouble to do an alignment why not do the measurements att the known to be correct point and not one that may or may not be close.
I agree too. Good trick to support on ball joints and add extra weight–I wonder how much weight that would be for a saloon.
Another way would be to remove the shocks and put in a turnbuckle on the shock mounting bolts. Then crank it down to the correct position.
You beat me to it.
I have a pair of turnbuckles which I modified for doing this. They’re M10 (or possibly M8). I made extensions for the end with right hand threads, just some M10 threaded rod with a washer welded to one end.
I initially made them as universal setting links for setting TBs - with one pair I can set any model E TBs. You can also use them for setting the front to mid laden, or if you have a car with the TBs out and you want to roll it around on it’s own wheels they’re just the thing.
I have a smaller set of turnbuckles for setting the IRS to mid laden.
@Robert_Wilkinson: I wouldn’t think of trying this on a saloon front suspension - it works on the E because you can fit them with the weight of the car pre-loading the TB. Having said that, if you could position the car on a lift so that you could have the weight on the wheels and still enough angle to remove the shock…
I recall seeing a simple method involving two hard plastic kitchen cutting boards and some grease. A pair per side. Video demonstrated easy movement. Novel and apparently effective. Have not tried it myself. Paul