Rear suspension

[alunwill]

I'm checking out rear springs and dampers for my 1966 S1 2+2. and I've come across a bulletin dated Sept, 1965.

It states that the aluminium spacing ring C19027 is not required.

What's the view of the experienced owners about this.

From the cost standpoint it's a saving of about £60 but it also lowers the ride by about 1/2".

Comments much appreciated

Alun

[mgcjag]

I would consider keeping your existing spring...are you sure the bulletin says not required(remove from existing set up) or there was a change to shocks/springs so not required....its not uncommon when fitting new shocks/springs to have ride height issues...plenty on the forum if you search "rear ride height"

[alunwill]

Hi Steve,

Unfortunately I don't have the springs, hence the reason for looking for new.

The bulletin which I found in the knowledge section refers to the intro of C25951 dampers and C25939 springs. It clearly states the top ring should be omitted. The confusion on my part comes from the fact that the parts diagrams on-line at martin robey clearly indicates it's required.

Alun

[mgcjag]

Jaguar may have ommited the spacer for their springs and shocks but anything you will be buying now are non original parts ..Steve

[alunwill]

Hi Steve,

I understand what's around is not original but from what I've read in the knowledge section the spacer was introduced for use with a shorter spring which in themselves were lower lb rated. C25939 when introduced was not only longer but also higher rated hence I suppose the need for the spacer was removed.

The problem I had with my old springs is that I had a mixture. 2 red and 2 blue so they're not really usable. My preference being to have a matching set.

Logic says follow the bulletin and omit the spacer. Has anyone else done this.

[Simonpfhc]

Alun,

Whatever you decide, as long as you fit the top bolts correctly (allowing removal in situ), it is a reasonably simple task to remove the shock/spring unit and either add or remove the spacer.

[angelw]

Alun Wrote:

The confusion on my part comes from the fact that the parts diagrams on-line at martin robey clearly indicates it's required.

Hello Alun,
I think you will find that the pictures used by Robey and clearly by SNGB, on their respective web sites are copies from Jaguar Parts manuals. That being so, there are many mistakes in the Jaguar Parts manual drawings. For example, the picture of the Door Window Regulator assembly for S2 2+2 and all S3 cars is supposed to be of a RH part in the Window Up position. However, what is actually shown is a LH part in the Window Down position, upside down. Accordingly, I would rely more on a memo than an assembly drawing.

Regards,

Bill

[alunwill]

Many thanks for the advise on this one

Alun

[alunwill]

Having gone round in circles on this one, I thought I'd put my thoughts down on what I think is correct.

I've been trying to order boge dampers for my rear suspension because I read they were a good replacement for the gun originals.

My understanding is this:-


8687 is the split retainer which comes with the damper.


C19820 is the seat which the spring sits on


C19027 is the packing ring at the top of the spring which increases the ride height. However, this was specified for use on spring C18977 which was 256mm open height, giving an overall height with spacer of 265mm.


Spring C18977 was replaced by C25939 in 1965 as per the service bulletin. This later spring C25939 has an open length of 266mm,  hence the service bulletin dated Sept, 1965 stating that the packing ring is not required.


So, from a ride height perspective, C19027 is not required if using C25939 springs.


So, the dampers keep the spring aligned at the top and the C19820 at the bottom does the same. However, I've now been told that the boge dampers do not have it's own retainer and as such the spacer C19027 is required because boge dampers don't by themselves. So boge dampers increase ride height and are not a replacement for the original series 1 dampers working with C25939 springs.


Is my logic correct or am I missing something?

[mgcjag]

If you have to fit extra parts on top or bottom of the spring then it will increase ride height but has this been taken into account in the boge manufacture?....however as mentioned in previous post above dont assume that just becaus a supplier has a spring with a Jag part that its manufactured to original spec or gives the same ride height as an original....Steve

[alunwill]

What's become aparent from my investigations is that boge do not take into account their need to use the top spacer to contain the jsg spring. Basically with the spacer it adds about 17mm to overall unloaded height.

The other thing I picked up is that the later standard spring 10.6", is being sold as the earlier version ( should be 10.1") depending on where you go.

Adjustables I think

[daverawle]

Don't the dust covers 8688 provide spring positioning without the need of the spacers? They would make no significant change to the ride height.

[alunwill]

Apparently not with the version boge currently sell. The spring size means they just slip inside. You need the spacer to retain the spring

[daverawle]

I replaced the old Gaz dampers with Boge today, just on one side at the moment. I had retained the original Girling dust covers and spring platforms and it went together without issues. The springs were sourced from sngb about 3 years ago, the originals having sagged to the point where speed bumps were becoming a problem, and are whatever they supply as standard.

As with the Girling dampers, which I removed 17 years ago, a packing piece was not required. The dust covers fit the new dampers exactly and centralise the springs. I'm not sure if the repro dust covers are of the same dimensions.

Having only done one side at the moment the car remains level, so no change in ride height.

The Sachs/Boge number is 319 812 and they are available from Simply Performance or ebay.

I've taken some pictures and can post them if they are of interest.

[alunwill]

Hi Dave,

would you post those pictures up please.

Also, what diameter springs do you have and any idea of the diameter of the dust cover.

It was simply performance that insisted the spacer was required and that the new dust covers didn't hold the springs in place, simply drop though!

alun

[daverawle]

Alun, I suspect there is some confusion between the dust covers, without which the dampers would still not fall through, although they would not remain centralised and the spring platforms, without which they would definitely fall through.

I can't measure the spring diameter until I get around to doing the other side but you can probably approximate it from the pics.
Dave