Fitting post-85 front shocks on pre-85. Doesnt work.

[Andyww]

I have just been fitting some new "proper" pre-85 front shocks which are back in stock at SJ.

Previously had post-85 with the spring platforms machined off. But they were not good at all. When coming off a speed bump there would be a loud clonk, which was the shocks going to full extension. Also the ride was terrible.

I suspected the post-85s must be shorter. This turned out to be absolutaly correct. The picture shows the post-85 with spring platform removed and the new pre-85 from SJ on the left. Both are on full extension and clearly there is a difference.

I think this issue must have caused internal damage as there is no compression damping resistance at all on them, although there is still extension damping. 

This also means that the LOTAC/Bilstein shocks if fitted to a pre-85 car with the spring platforms left off will have the same problem so I am very glad I didnt spend £800 on a pair!

[SciroccoEV]

I measured the stroke as being the same (approx. 70mm) and will be using an extended top mount.

[Gis]

@Andyww how much do you tighten the top rubber mounts on the reproduced SJ shocks? I could not find any recommendations in the service manual. Following your lead, I’m in the process of replacing my modified, post 85 shocks to the new SJ shocks. Any advise is much appreciated here mate.

[Andyww]

41 minutes ago, Gis said:

@Andyww how much do you tighten the top rubber mounts on the reproduced SJ shocks? I could not find any recommendations in the service manual. Following your lead, I’m in the process of replacing my modified, post 85 shocks to the new SJ shocks. Any advise is much appreciated here mate.

The top stem on the SJ ones is shorter than the original and there is no room for a locknut which is unfortunate.

What I did was tighten until the nylon of the Nyloc nut was fully engaged with the thread on the stem but no further. At that point the rubbers are quite compressed, possibly slightly over-compressed. So there isnt a choice in the matter really. Make sure the shoulder on the metal washers top and bottom site inside the chassis hole.

The SJ ones seem to be gas dampers as they expand by themselves to full extension. To fit them I had to use large cable ties to tie them to full compression. A bit of a faff actually. If you were removing the lower link completely it would be less of an issue but I only disconnected the top ball joint from wishbones , loosened the wishbones to chassis and folded them up out the way.

Heres another thing which was interesting, I mentioned it on another thread, I wonder how many other people have unwittingly done this:

For years I have always wondered why my car sat around 15mm higher on one side then the other at the front. In the process of fitting these I found the reason. When tightening the top wishbone bolt with the car on the ground, as you are supposed to, I didnt know that the whole of the long stud through the chassis was rotating as I was tightening the front nut (holding rear nut with another spanner) and taking the centres of the rubber bushes with it. So it was winding up the bushes. What I had to do was work out where the wishbones were supposed to sit with the car on the ground, jack it up, disconnect top ball joint and torque the top wishbone nuts using trial and error until it was torqued with the wishbones in the right place. Every time I tightened it they would rotate so had to account for this. After that the problem was completely solved. This issue was causing the left side to ride high and the right to ride low. 
I think the cause of this issue was using copperslip on the long studs when I last rebuilt the suspension, which got between the wishbone bushes and chassis.

[Gis]

Great advice Andy, including the 15mm height difference resolution. I have exactly the same observation on mine. Will try to fix that too then. Thanks mate 👍

[LotuStuart]

I have no idea if this is relevant or helpful, so ignore it if it is no use or obvious!

to stop a threaded shaft from rotating and travelling I use two nuts locked into one another to hold one end still and stop the threaded shaft from travelling. 

[Andyww]

20 minutes ago, LotuStuart said:

I have no idea if this is relevant or helpful, so ignore it if it is no use or obvious!

to stop a threaded shaft from rotating and travelling I use two nuts locked into one another to hold one end still and stop the threaded shaft from travelling. 

Its almost relevant. On the front end where there is plenty of room there are indeed 2 nuts fitted. On the rear end there is only one and its only just accessible as its right up against the body so you can hold it but not turn it. So you have to turn the front end with the locknuts and the shaft therefore turns.
Actually I think you can access the rear single nut through a hole in the body but it would mean tearing out the footwell carpet which would likely damage it. I seem to recall on the Europa there is a rubber bung in a body access hole here.

[skiing]

Interested to read this - how are the new SJ shocks working out in terms of ride etc?

[Andyww]

The SJ shocks are good for ride and performance. 

Only factor I cant comment on yet is durability as I have still done very few miles on them.

[skiing]

Thanks Andy - I don't need to do mine yet - but it would be good to have the standard Lotus ride if possible 

[pmth95]

On 11/08/2023 at 05:16, madmax said:

the front suspension can be 'dangerous' to disassemble with those springs.

With the right spring compressor it was actually quite straight forward both front and rear. 

[madmax]

Wow - those spring compressors look formidable. I have seen similar ones on here on various posts but have only found the rather precarious 'hook' type readily available for sale. I have a pair of these and I don't think they're up to an Esprit front spring compression.

I like the look of the ones in your picture as they seem well up to the job, but I note that you're based in Detroit so if anywhere has some decent spring compressors, Detroit will - they're massive!

Thanks - it gives me something to aim for when I eventually get to the front end rebuild

[Clarky5150]

The hook type are more than capable of esprit springs. I use them in situ to release tension on the coilovers when adjusting the spring plate. torque them both a little at a time to keep the spring straight. Dont forget the Esprit is a fairly light car so poundage isnt huge