Hi,

I am going to have a wheel alignment done tomorrow and I remember the last time, the rear toe was asymmetric (one side slightly out of spec) but the workshop wasn't able (or willing) to fix it. I have always thought that all XJ40/81 had adjustable rear toe but indeed it looks like it is only possible from VIN 687219 on. My car has VIN 675xxx so it should have the non-adjustable rear hub. But when looking at the parts catalogue, the only difference seems to be the pivot pin (#14 in the drawing). So could every XJ40/81 have adjustable rear toe by just exchanging the pivot pin?

EDIT: Just searched a little bit and found a picture of the newer pivot bolt, it looks pretty much the same as the one I have, except it has a fixed head with an integrated washer. Is that the whole deal? If the rear toe depends on the position of the pivot bolt within the hub, it should be adjustable anyway in my opinion, just need to locate it at an adequate position with the given lock nuts and washers.

Thanks,
Oliver

 

These TSBs were issued a few decades ago when I worked at the dealer.
These may help explain.

 

Thank you, but actually these bulletins don't precisely answer my question. Do you believe the rear toe adjustment capability is implemented through the new rear wishbones?

EDIT: I think I finally got it, when looking it once again (and some more sources), it's not the hub or fulcrum bolt that adjusts toe, it's indeed the whishbone, which has a slot instead of a concentric hole to take the hub. So if you want to adjust toe on pre 687219 cars, you'd need to cut a slot in your wishbone's hub seat ... which is probably not recommendable.

So finally: what else can you do, when your rear toe is out of spec?

 

I remember some later Jaguar models (X308 or X100?) had slots for adjustment on lower control arms or frame mounts but used STRAIGHT BOLTS from the factory.
We were supposed to get new ECCENTRIC BOLTS from the part dept to replace the straight bolt when an alignment was performed.
Cutting a slot will work on the rear lower control arm if it is done CORRECTLY.

You don't need an eccentric bolt if it is 'nudged' back and forth until the correct reading is obtained and 'locked-down' TIGHT!

The eccentric bolt will only work with welded raised bosses for the eccentric 'washer' to force the bolt to move 'side-to-side' as it is rotated.

 

Do you have some source for these eccentric bolts? Reading this, I believe alignment issue where quite common on these cars, weren't they?

So you say even the bolt-hole for pre-687219 cars provides some play to tackle rear toe issues? Should be worth a try.

I already thought about retrofitting the late XJ40 rear wishbone, but most parts aren't available any more and even getting them in used condition will require quite some money. I've already thrown a lot of effort and money at my suspension issues and I gotta stop somewhere.

 

I have BINS AND BINS of 3 ring binders and some of that info was transcribed to .pdf documents.(Jaguar started that in the early 2000s)
The info is somewhere in my 'piles-of-documents'.

I remember 'doing alignments' on some cars and having to go to the parts dept for the eccentric bolts to get the suspension into alignment.(been way too many years to remember exact details)

Sometimes a skilled mechanic just has to 'deviate-from-the-norm' and modify factory parts.
We did that upon occasion and sometimes we were 'sanctioned' with the 'mod' and sometimes admonished and sanctioned with a 'back-flag' of payment as punishment for deviation of procedure.

Mechanics always try to come up with 'easier' or more efficient ways of repairing faulty/broken machinery.

 

Late XJ40's with cast wishbones have the eccentric setup. My DD and my parts car are set up like this.

 

What I notice when standing behind the car is that on the right side it looks like the wheel stands further out than on the left side. I think that could be caused by the deviating toe, but it could also mean the rear axle as a whole is not well centered. Gotta try to measure from wheel hub cap to the wheel arch.

Update: tried to measure it and it looks like the hub cap is about 1/4-1/2 inch further out on the right side. My measurement might be affected by camber ... well, let's see what the guys in the car shop say after the alignment, might be tomorrow until they can do it.

 

Got the car back from the alignment and the camber on the front right is out of spec, it's too negative (-1°18'). Bushes, ball joints etc. are all new. What's going on here? I already installed camber shims to the v-mounts (which helped to bring the left side camber into spec), but the right camber is even worse than before.

On the rear the toe on the right hand is in spec, but on the left hand is out of spec, too (-1°01'). Right side toe is even better than last time, even though I did not change anything. The only thing I did on the rear is to lower the diff because I needed to access the diff filler. Therefore I loosened the right control arm.

 

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