I would like to re-hash a previous subject.

The Jaguar Mark 2 Models Service Manual states that "A packing piece and 8 shims must be always fitted between the wishbone levers and the upper ball joint; their relative positions may, of course, not always be the same."

The manual also has an image: Figure 15. Shown as an attachment below. This image clearly shows five 1/16" shims to the left of the ball joint and three 1/16" shims to the right accompanied by the wider aluminum packing piece.

Today I installed the shims and packing piece EXACTLY as depicted and described in the Service Manual. Once this is done it is impossible (at least it seems so to me) to mount the rubber bump stop and its bracket to the mounting holes in the wishbones. The holes for the bolts will not align as the wishbones have been separated too far by the 8 shims plus the packing piece! See the photo below and notice how far off the alignment is. By the way, I know the rubber bump stop is upside down.

TilleyJon concluded in another post that the Service Manual must be in error. Based on my experience today, I would have to agree, but this sure seems odd.

Can anyone offer an opinion (it would be nice if it was based on fact and actual experience) about this subject? Could someone check their car and report on the findings?

Thanks very much. I am truly puzzled by this.

Lin

 

I have to concur obviously, my car never had eight shims when I got it, it would be interesting to get some wider consensus of real life shim numbers to determine if the manual is in fact incorrect as it does seem odd that it is, but not impossible.

 

I have a new theory, but it is only that and I could easily be wrong. Earlier cars had pressed steel upper wishbone levers while newer cars had forged levers. The earlier pressed steel levers used a rubber rebound stop with a single screw mounting and did not mount across the wishbone arms. Although the figure in the manual shown as my attachment shows the later forged levers with eight shims, I wonder if it is an accidental carry over from the pressed steel lever cars?

A friend, Eric Kriss, has a 2.4 and photos of his suspension using the pressed steel levers show 8 shims plus the packing piece. His car also uses the old style rubber rebound stop. See his post with photos here: Front suspension restoration, part 3 - Jaguar Mk2 Restoration.

Again, I just don't see how it is possible to use eight shims on the forged lever cars. I am still left with the conclusion that the Service Manual is in error, but I would love to have additional confirmation or an explanation and correction.

Lin

 

Hi Lin,

I will check my Mk2 and report back, as I have been thru this exercise, however it was quite some time ago!

In regard to the manual and the Kriss Motors resto, I am sceptical that ALL cars would necessarily need ALL 8 shims and the spacer, otherwise there would be no point in being able to alter the number of shims to get either the factory settings or setting the car to one's individual preference. As an example, I have disregarded the factory CAMBER settings and set my car to 1 degree negative due to my choice of wheels & tires.

I am glad you have raised this issue, as rather weirdly, I find suspension alignment a rather fascinating subject.

 

Lin, I have an old front suspension with pressed wishbones, I will have a look and see what that has, for interest what is the center to center dimension of the bolts holes of your bump stop ?

I will measure the pressed wishbone dimension as a comparison.

Peter, the requirement for a certain number of shims has to be in order to fit the bump stop, the positions are totally variable including the packer, so the top ball joint can be shifted about +/- 1/2" which gives quite a bit of adjustment.

 

I have checked the dimension across the faces of the wishbones on the pressed wishbones (total width of balljoint and shims) and it is .2" larger than the newer forged wishbone suspension I have on my car, that equates to 3/16" which is in fact 3 shims.

The bolt holes centers on my bump stop measures 3.5" , the bump stops on the pressed wishbones is different so I can make no comparison.

 

Jon,
Yep. 3-1/2" center o center for the bump stop on my car.
Lin

 

Jon, your comparison of the pressed versus forged lever arms supports my theory that they are clearly different and supports your theory that the manual doesn't differentiate between the two which it should have done. All further confused by showing a diagram with 8 shims and forged levers!! This kind of thing just drives us hobbyist crazy because we don't know better.

Thanks for checking.

Lin

 

It doesn't drive us crazy, we are already there for starting hese projects.

It's just another hurdle to jump, how many issues will you / have you already overcome, it just makes us work harder, has to be all part of the fun

 

I think you are taking the shims too literal, these old cars use shims to adjust suspension settings and there is no one set requirement. You adjust the suspension to how you want the car to handle and drive. Factory settings of all cars are ultra neutral to generally get the most wear for tires and MPG but that is NOT typically ideal settings for handling and performance. You should not worry about how many shims are used but rather the desired suspension settings.




As someone else mentioned for better handling you typically want a slight negative camber and set the other settings to match. You thus add or delete shims to get there and not worry about how many are used.

 

Primaz the question is not regarding the setting, it is the number of shims, I know that the 2 do correlate, but in this context, it is not the position of the shims, which we all agree can be altered to change the suspension settings, but the total number of shims.
Too many and you can't fit the bump stop, too few and the same would apply, the fact is that the manual states 8 shims are required does not allow the bump stop to be fitted, so it was simply to ascertain how many shims are fitted in real life to owners cars which Lin and I think is in fact 5 plus the packer.

Also too many or too few would add more strain on the wishbone bushes which may cause early failure too.

How many shims have you got fitted on yours Primaz ?

 

I just completed a complete rebuild of my suspension system that has the early style wishbones. There are only four shims on each side of both right and left side wishbones and only one packer on each side as opposed to two. I suspect alignment had more to do with how well the basic construction was of the frame section. It was probably build very accurately, but some variations might account for the number of shims required to meet factory specs.

 

Just to clarify: when I mentioned that there was only one packer on each side, that means there is one packer total on each side of the suspension system and not the wishbone. Only one packer total on each of the wishbone assemblies.

 

This makes sense, the newer wishbones were fitted from Chassis No 215154, it so far appears to only effect the newer wishbone style, thanks Ted

 

I will have to check but I am pretty sure I DO NOT have eight shims and I have driven the car very hard for over 60,000 miles with no issues. The car was set with about 1 degree negative camber all around for improved handling without worrying about the amount of shims but rather the suspension settings desired.

 

Thanks Primaz, it will be interesting to know.

I don't have a choice on the rear axle on mine, but I will be setting the front to -1 deg when I get that far.

 

Here's the setup on the beast, Lin. It was happy with 5 shims and a packer. After living through this last election I'm surprised you're having a hard time questioning something you've read - doesn't matter the source, does it?

 

Hilarious Doug, you have a very valid point.

 

How true, Doug. Thanks for the photo.
Lin

 

Jon, I only have 3 but I forgot my situation is not the norm as I have installed custom lower A-arms and coil overs so it is way different from stock.