How to replace chassis fulcrum pins?

[mrpeugeot]

During my recent rebuild of my front suspension, I noted that the chassis fulcrum pins appear to be a weak link in the front suspension design (in the sense that they are the least robust component). While doing my rebuild, I would have liked to remove and replace these just for peace of mind; however, I could not find a procedure to do so.

My car has an early Spyder sheet metal chassis that has removable fulcrum pins that pass through the suspension turrets in a metal tube (upper) and through the cross member (bottom). They seem to be a friction fit (although, to be honest, I did not try hard to move them).

Beyond the obvious challenge of removing such a long nut with body work in the way (I'd assume cutting a small access hole in the front portion of the wheel well would be the solution to removing the upper fulcrum pin), what else is required to remove these? And do they need any lubrication or special alignment when new ones are inserted?

Thank you,

Adam

[billwill]

There was some discussion on this long ago.

I don't think anyone contemplated changing them while the body was on.

I seem to recall they have to be welded on the original Lotus chassis.

They should not have any lubrication; as far as I am aware, the centre of the suspension bushes do not move, they are rigorously bolted to the chassis. The outer only moves by virtue of the flexibility of the rubber in the bush.

[RichardHawkins]

Adam,

My workshop manual Section A pages 8 9 & 10 Additional Information, shows a procedure for pin replacement. Page 4 Section A states that pin damage requires a new chassis.

I have heard a story that insurers would not pay for new chassis if the pins were bent, and that Lotus were obliged to offer the procedure on Pages 8 to 10.

Hope this helps

Richard Hawkins

[Chancer]

Some while back an original factory kit for replacing the fulcrum pins was sold on eBay.

En gros it was a hole cutter with an alignment fixture, the pins and some large penny washers to be welded on from memory.

[rgh0]

Replacement of the Spyder chassis pins is a different exercise from the orginal Lotus ones. I have never tried it but I have always assumed they are just pressed into the tubes. I presume if you used a suitable spacer you could pull them out with a nut on the thread on the end of the shaft.
You dont say why you want to replace them unless they are damaged in an accident in some way they should never need replacing ?

cheers
Rohan

[mrpeugeot]

Thanks, all, for the replies.

Rohan is correct - according to Spyder, the fulcrum pins on their chassis are available in removable form.

As for why - well, I just rebuilt the front suspension down to every nut and bolt, and these were the only ones I didn't (because I just couldn't figure out how to do it, and would rather not guess). They strike me as likely being subject to metal fatigue over time, although I haven't heard of any sudden failures from the community.

[Higs]

Hi

I save just rebuilt my early Spyder chassis with the body off. The bolts just slide into the tubes - they are not an interference fit so don't need a press.

Getting them out with the body on is just an issue of space - or lack of it.

The pins are not under extreme load - the shock and spring transmits most of the loads to the chassis. The way that they are constructed means that both ends of the bolt would need to fail for the suspension to collapse. This is unlikely to happen simultaneously - and you will hear plenty of complaining from the suspension if and when one end fails first.

Rohan is correct - unless you have a specific reason to worry, I would leave them be.

Hope this helps

Richard

[Craven]

Hi Adam.
The Spyder chassis uses the arrangement you describe in your post, the fulcrum pin for the wishbones are simple a push fit through the tubes. The reason they appear to be held fast in some way is probably due to some corrosion between the pin and its tube, use a good penetrating oil and with the two locknuts try to rotate the pin when gently tapping the end.
There is space to remove the bottom pin but an accurately placed ? inch hole, can be made by extending the pin to touch front inner wing and pull pin through for the top one.
New Stainless Steel pins plus all nuts, washers are available from Spyder use Copper Ease on re-assembly.
For What it?s Worth.
Ron.