1970 S4 suspension rebuild

[Simmo78]

Good morning all, I am in the process of rebuilding the front suspension on an S4 FHC and have come across a number of anomalies between the O/S and N/S.
Firstly when removing the O/S I found two washers (one either side) of the lower damper bush between the wishbone arms. However there were none on the N/S.
I can’t see any washers shown in the exploded parts diagram in the manual, so I suppose my question is: are there supposed to be any washers on any of the ‘inner’ faces of the wishbone arms?
I should note that the entire front suspension is currently original, with the original arms, dampers etc..
Looking forward to any replies,
Thanks in advance Simmo

[dpchamp87]

I had to put washers between the wishbones and the chassis to give chassis clearance at the mid point of the wishbones. I put them on the other end as well to avoid any binding.

[Roland]

Simmo,

I have found fitting poly bushes the front wishbones on my Elan problematic. This may be due to variations in remanufactured wishbones dimensions and variations in the actual bushes on the market.

In my experience the crush tubes in the polybushes (with the bushes fitted in the wishbones) can be marginally shorter (0.1 -0.2mm) than polybush, more than this and I reckon they bind up. The polybush does tend give a little when fitted but this 'give' varies because different manufacturers are using different materials. I tend to fit each individual bush to each wishbone, torque up and then move the wishbone by hand to ensure the polybush is not binding and working properly as a bearing.

My first attempt at polybushing the front was using Superflex bushes, these elongated on fitting in my original Lotus manufacture front wishbones and the crush tubes were then around 0.5 - 1.0 mm short. The wishbones locked solid and I removed the whole lot without even trying them on the road.

I fitted Autobushe next and drove maybe 300 miles on these. These bushes were too loose in my wishbones although the crush tube length was OK. The wishbones migrated inwards towards the chassis because on that side of the bush there are no washers to prevent the movement.

I then fitted Super Pro bushes and found the fit to be perfect. I also put large machined washers/spacers on the inner side to prevent the migration/movement mentioned above.I did speak to SuperPro about fitting these washers/spacers because their instructions make no mention of using them. They did advise fitting them but when you do this you also have to use washers/spacer at the outer end of the wishbone as well (at the damper, trunnion and top ball joint).

The car is now really good on the SuperPro bushes however the whole exercise was more difficult than I expected. There is a surprising difference across the 3 manufacturers I tried in terms of dimensions and materials. Note personally I think the basic material that SuperPro uses is superior, very tough but still flexible. During this whole exercise I ended up speaking to each manufacturer, the only one I got technical sense from was Super Pro and they design their own bushes. I have no affiliation to Super Pro and I have used them for years on my two 911's. I actually didn't use them first on my Lotus because the Lotus specialist market sells mainly Superflex and Autobushe so I thought the Lotus Elan expertise would be with them.

I think to get the ultimate Polybush fit and performance on an Elan you probably need to custom manufacture your own bushes and this is a project I may try sometime but it is time consuming. Col Croucher at Elantrikbits has done this and has information on his site.

Regards

Roland