Oh, how I miss living in Germany...
The adjustment you're having done is called "Toe" in English. It's typically set to slight toe-out on our cars to enable sharp turn-in. If you search the forum you'll find recommendations on what it should be for NORMAL driving (I settled on total toe of +0.16 degrees on mine), but if you're pushing towards the 200 km/h with some regularity, some toe-in like you're doing sounds like a good idea. I'm a novice at this though so hopefully the more seasoned users here will weigh in!

 

Minimum Toe in is called for, however, high speed stability is most affected by caster (think motorcycle choppers with the exaggerated front wheel extension), followed by camber and toe settings.

of course, alignment is a system where all 3 settings have to be in harmony.

What most developers use is slight toe-in, slight negative camber, which gives maximum tire contact in cornering, and a few to several degrees of caster for high speed stability. More caster does make low speed steering more difficult. But since these cars have power assist steering, more caster has no drawbacks.

The exact specs are in the factory spec file attached

Z

 

125 - 150 MPH? Man, I'm green with envy. There's no place near me where you could go that fast if you wanted to. I think about 95 MPH is all I've been able to do, and only for very short periods.

 

Try doing 125 to 150 mph around here and you will go directly to jail....

 

For sure! The CA vehicle code says anything 100 mph and over is arrest and impound the car. I have no idea how often it's enforced.

 

oh i didnt have that in mind. yeah we have many spots without any speed regulations here.
As soon as the weather gets better here ill look for the alignment and post the protocol for you.

I will look in the verhicle spec to see how far off i am abd correct it as i have to pull the front struts anyway for the baxtor modification on the mounts.

thank you so much guys for the assist.

 

FWIW, the only time I got anywhere near the 155 limiter speed (130MPH/209KMH) the car was rock steady.

Try around here and you likely to go into the sea

 

Have you had an alignment done and specifically the caster, and does the new bushings fitted include the lower control arms?
The lower control arm bushings can be accidentally transposed, and if they are l think a huge change in caster (to the negative) will result.
That would be no fun drive.

 

This is another thing that might help in addition to the proper alighment advice.... calm down that nuclear assist power steering! I haven't tried this yet, but am planning to - the level of power assist is insane - makes me nervous even thinking of going 150 and having to sneeze. This apparently tones the assist level down, which I'm hoping translates into a little more amplified feel and less nervousness.

https://www.jaguarforums.com/forum/x...a-95887/page2/

 

Front Caster Adjustment is done with the washers that are on the bolts. In the workshop manual it appears for different areas of the world. On my xk8 it is totally symmetrical (not as it says in that manual), I asked both in the forum and in the workshop and they told me to leave it as it is. I wouldn't play with those things, but for more speed you have to move forward (like in motorcycles and bicycles). Leaving the total thickness of the washers the same, you can play with other caster distributions to increase the Caster. Looking at the Zray PDF I see that the tolerance is very wide (almost similar to the nominal), with a good alignment machine and patience you can take the tolerance to the extreme. I wouldn't touch anything of the original ("but we don't talk about cowards")..

 

When I pulled my fulcrum bolts yesterday, I noticed that the shims were in disarray probably due to the person who installed the Welsh mounts for me. Kind of answers itself as to why I am redoing things...

I have a question regarding the placement of the washers with the cone protrusions. To properly contact the bushing sleeve, the cone protrusion would face inward, correct?
Why would I find a shim washer on the outside between it and the bushing?

Also, there are yellow dotted fiber shims which I assume are placed directly against the rubber bushing with the yellow pattern facing outward, correct?

Thanks, now off to measure the widths of the shims of which I now have a nice collection.
The car was aligned very nicely. Now I will probably have to write that off and find someone who can redo it after I setup the caster properly. Yuck.

 

I just replaced the shims with 1/32 and 1/16 generic U shaped alignment shims with the ID cut out slightly because the bolt is a little larger in diameter.
See posts 11 and 13.

 

Thanks, much appreciated, and I might do the same. It is more logical and easier for an alignment tech.

What I was asking related to the end washers, under the bolt head and nut. How are these positioned, and is there anything between them and the bushing itself?
Thanks.

 

The JEPC shows WASHER CAC3533 (8 total) on either side of each bush.

 

Humm... thank you.
I have to do some counting as there are some things missing.
Much appreciated.

 

There are 4 total upper arm bushes, 8 washers total, 8 shims total, (4 thick and 4 thin) and half go on each side.

 

Thank you!

 

Shim arrangement different for world regions, all listed in manual. Castor requirements vary due to different road building standards for camber and more obviously, left and right hand drive. Thanks

 

One thin shim missing after I found all of the pieces, obtained a WASHER CAC3533 from a friend, and found the missing end pieces for the bushings which are the yellow fibrous ones.

Should have taken a picture of the disarray in which everything was installed.

Considering doing a rest of world neutral caster install. Might make the steering a little quicker on the twisties.

Question, my alignment was done perfectly by an excellent shop on the other side of the country with the vehicle at proper ride height and laden weight. Would toe really change that much with the caster changes?

Would love to avoid having to find a place to do it properly.

 

Question: when replacing all of the shims in the proper location since the packs are not intact, does it matter how one positions the thick and thin in the whole sandwich so to say. Thanks.