Took some measurements today after rebuilding my rear suspension.
______ Toe In … Camber Left__ … 0.2° … -0.5° Right _… 0.2° … -0.5° Total _… 0.4°
I have 0.4° Total Toe In while the specs ask for parallel… not much I can do about it besides starting heating and bending wishbones.
Me thinks it’s straight and it’s not much, so not a very serious matter… ?
My RWD Mercedes calls for twice that.
The most important question though is, should I leave the Camber at -0.5° or adjust it to -0.75° ?
The manual calls for -0.75° +/- 0.25°.
As both settings have the effect of pushing the wheels in, my rationale is that less Camber would maybe compensate for the more Toe In ?
Does it make any sense ?
Three comments, two as a decidedly non expert the other from memories.
toe equal side to side and the deflection is too small to change anything in driving or tire wear. Might even be within the tolerance of the device used to measure it or the method.
You changed nothing in refurbishing the assembly that changed either measure. It remains in factory tolerance.
Way back, bending suspension parts to get the desired degrees was not uncommon. Bear, a major maker of the equipment provided various hooks chains and jacks to do just that . As forgings, the can bend, cold…
Added. Way back when, I discvored that the beam front axle in a 40 ford truck I was “fixing” up had a decided bend on the passenger side. Yeah, it came to me with a very roughly straightened fender/wing!! I fond another I far better condition to replace it.
A chain, a jack and a carpenter’s framing square and it was straight. Bent, cold…
I may have used a string to see if the wheel base on each side was the same or quite close.
Dirt jalopy racers often bent in radical + camber for the right front wheel on circle tracks… Cold.
In principle the toe is invariant with suspension travel, while camber inevitably varies. The whole point of the Jaguar set-up is to avoid rear end steering - which relays to toe. Ie with excessive (or ‘loose’) toe the outside wheel toe in a turn will predominate - causing ‘tail happiness’ when changing direction. Which is very disconcerting and noticeable - if you don’t feel it; you don’t have it…
The camber is adjustable, the toe is not. However, Carl’s remarks are very pertinent; the tolerance of the measuring devices plays influences reading. And for camber; the ride height plays a part; specs are given with setting tool height.
The toe specs are given as +/-1/32" - it is not given in degrees. Converting to degrees leads back to precision, and gives excessive toe - I suggest you measure toe related to specs…
In short, and pending remeasuring with ‘correct’ procedures, I think you should let sleeping dogs lie. Under no(!) circumstances and given the symmetry if the measures presented - using force on the rear suspension for ‘adjustments’ is an absolute no no!!
Yes and no…
Total toe is invariant indeed, but the set-up is such that the control arms will slightly pivot the cage when the car lists, like in a fast curve, inducing some passive steering.
I agree with you, I will will not mess with the wishbones this time and I’ll leave toe as is.
I get 1.5mm difference measured at the edges of the rim.
Translates to about 0.2° toe per wheel.
My question is about Camber.
I am at the lower end of the specs, -0.5°
Should I bother to adjust it to -0.75° ?
Will it make any difference in stability or tire wear ?
I was watching a You tube on my Visio when it was still “smart”. The use of a huge recovery vehicle. The need. an over turned semi with a very long trailer, loaded with huge logs for the mill.
Two lane back country road. Two "recovery trucks’
How to pull at a 90 degree angle??? Enter triangle…
A pulley block aka “snatch block”. Get the angle just right and secure the “pull” at the other end with the second truck. Winch work at it’s finest . Mastering the triangle at work…
I can envisage the tree the cords and the wheels in your example!!!
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It relates to the precision of your measurements, Aristides - within specs is good enough…
Increasing negative camber will slightly increase track, which is ‘good’. But it will also ‘tilt’ the wheel - which will alter/reduce tyre footprint, and likely increase asymmetric tyre wear as wheel, which is ‘bad’. Leave it as is…?
Its arguable that Jaguar built in rear toe changes - it encourages rear wheel steering, which is an abomination. Lower rear tyre pressure by 5 pounds, and twist the steering wheel - it’s an experience…
The cage is rigidly mounted, and the lower wishbones maintain hub and wheel fore and aft alignment - and adds to cage stability. Only bending and play can alter toe…
Frank
xj6 85 Sov Europe (UK/NZ)
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