Rear suspension

Talk about the E-Type Series 1

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alunwill
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#1 Rear suspension

Post by alunwill » Thu Apr 10, 2025 8:53 am

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
Al

Series 1, 2+2
undergoing renovation

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mgcjag
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#2 Re: Rear suspension

Post by mgcjag » Thu Apr 10, 2025 10:53 am

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"
Steve
69 S2 2+2 (sold) ..Realm C type replica, 1960 xk150fhc

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#3 Re: Rear suspension

Post by alunwill » Thu Apr 10, 2025 2:32 pm

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
Al

Series 1, 2+2
undergoing renovation

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mgcjag
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#4 Re: Rear suspension

Post by mgcjag » Thu Apr 10, 2025 3:06 pm

Jaguar may have ommited the spacer for their springs and shocks but anything you will be buying now are non original parts ..Steve
Steve
69 S2 2+2 (sold) ..Realm C type replica, 1960 xk150fhc

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alunwill
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#5 Re: Rear suspension

Post by alunwill » Thu Apr 10, 2025 9:32 pm

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.
Al

Series 1, 2+2
undergoing renovation

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Simonpfhc
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#6 Re: Rear suspension

Post by Simonpfhc » Fri Apr 11, 2025 6:45 am

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.
Simon
62 3.8 FHC
91 Porsche 928GT
Find me on Instagram and Facebook @oldcarfixer

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angelw
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#7 Re: Rear suspension

Post by angelw » Fri Apr 11, 2025 9:58 pm

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 there 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

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#8 Re: Rear suspension

Post by alunwill » Sat Apr 12, 2025 9:38 pm

Many thanks for the advise on this one

Alun
Al

Series 1, 2+2
undergoing renovation

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#9 Re: Rear suspension

Post by alunwill » Tue Apr 15, 2025 1:39 pm

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?
Al

Series 1, 2+2
undergoing renovation

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#10 Re: Rear suspension

Post by mgcjag » Tue Apr 15, 2025 2:24 pm

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
Steve
69 S2 2+2 (sold) ..Realm C type replica, 1960 xk150fhc

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#11 Re: Rear suspension

Post by alunwill » Thu Apr 17, 2025 4:41 pm

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
Al

Series 1, 2+2
undergoing renovation

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