Front Spring/damper Replacement

[hatman]

I'm trying to fit replacement front springs/dampers (Armstrong new-old stock) to my S4 but I've encountered a wee problem. The shroud on the units is about an eighth of an inch too wide to fit inside the side gaps in the suspension turrets and, although I can attach the units to the top mounting point, as they won't tuck inside the turrets, they stick out too far at the bottom for them to line up with the lower wishbone mountings.

The springs that are on the car at present don't have any shrouds on them and are consequently slightly narrower, thus enabling them to (just) fit inside the turret gaps. They're not the original units, having been put on about ten years ago. The chassis is a genuine galvanised Lotus replacement and therefore, I take it, has correct spec turret side-gaps and, as I say above, the spring/shock units are the original Armstrong type so should be a perfect fit.

Help! What do I do now?

[nebogipfel]

I had a similar situation on my chassis (original type Spyder replacement) with the body off.

When fitting the bottom bolt the strut was slightly under side load. It is slight and I assume that when full weight is back on the chassis the angle will change slightly and the problem will be solved.

I assume you could slightly relieve each side of the aperture if you are only talking about 1/16" each side (presumably just at the top).

I have often wondered why they are sometimes fitted without the shrouds? They certainly had them as OE.

[hatman]

Thanks for that, Neboqipfel, but in my case we're not talking slight side load, unfortunately, we're talking 'impossible to push far enough in to have even a remote chance of the bolt holes lining up'! And although one sixteenth each side doesn't sound like a major deal, it's actually one sixteenth each side (at least - my measurements were no more than 'line of sight' with a ruler as I don't have a measuring caliper) measured against the existing interference-fit units (they actually chafe against the edges of the gap - evidenced by marks on the springs and a metallic scraping noise when negotiating road humps).

What can I do - take an angle grinder to the turrets to widen the gaps? Seems a bit crude and no-way-back and, surely, such butchery shouldn't be necessary, especially as we're talking standard-fit units here. Any one else been down this route?

[Foxie]

"What can I do - take an angle grinder to the turrets to widen the gaps?"

Don't do it !

I'm 20 years changing shocks and springs on Plus 2s, I've never seen a "shroud" on a shock. Do you mean they are outside the springs ? I'm not clear what the problem is, can you post a photo ?

Sean Murray

[rgh0]

The shrouds were always a tight fit on both my Elan and Plus 2 chassis. I have 4 old original armstrong shock units and the paint has been rubbed off both sides at the top of the shroud where they fitted in the chassis.

It sounds like normal manufacturing tolerances and perhaps the galvanising thickness have conspired to turn a tight fit into a not fit situation for you. If the units fit without the shrouds I would just run without them. I have run the cars this way for the last 10 plus years since changing over to Spax units that come without the shrouds with no problems ( also ads lightness)

Rohan

[john.p.clegg]

Remove the shroud and replace with a modified wasing-up bottle cut to fit,this will protect the springs from road muck,is lighter and flexible
John

P.S.

You will have to machine the top off the original shroud or fit washers/spacers to fit the split collars

[hatman]

Sorry, Sean, but I don't know how to post a photo here but if you have a copy of 'The Classic Lotus Elan' video you'll see that the front spring/damper unit on the car that Paul Matty is using as a teaching aid has a shroud on - it's that blue metal tube that covers the top half of the spring.

Also, on the Paul Matty car (in which I notice the unit, shroud and all, fits comfortably inside the turret cut-out), it does seem that the turned-over outer edges of the turret walls have been removed to leave merely the thickness of the steel from which the chassis is made (which would, of course, give a fair bit greater width to the gap into which the shrouded unit has to fit) so has someone taken an angle grinder to that chassis or am I just imagining things?

Further on in the same video on the 750 car that Pat Thomas is showing the interviewer it definitely looks as though the turret walls have been bowed out to make extra space for the suspension units to fit inside or, again, is it just my wonky telly?

[Hamish Coutts]

Guys,

Not sure if this is any use but I was working on the front suspenders of my +2 this afternoon and I noticed that my fromt shockers had the same blue front shroud covering the top portion of the spring. The shroud bit fitted into the housing on the chassis (spyder); just. As in an earlier post, the paint has been worn off on both sides.

Hamish.

[Foxie]

As it happens, I got this video some time ago, watched it in FF mode at the time, just watched it in full. Paul Matty sure chews gum !

Saw the shrouds as you mention. I have no hesitation in recommending you remove/cut them off where they interfere. I know the springs (without shrouds) just about fit in the turret opening. Definitely don't cut/grind anything off the turrets.

My original Lotus chassis ( without any grinding ) developed major fatigue cracks in the area which the shrouds interfere - braking puts large torsion loads on the turrets here through the unbraced top spindles.

The shrouds might help to keep salt/grit off the shock rods, but I've never seen any corrosion on them.


Sean Murray

[hatman]

I spoke to Pat Thomas today to pick his brains in the matter and also ask about the apparently widened turret-slots on his 750 racer.

Says he's never come across this non-fit problem before but, in no circumstances should I be tempted to remove the shrouds to make the units fit as they're not just put on to keep road crud off the springs - they're there, apparently, to prevent the springs themselves from bellying out (the non-shrouded springs fitted to my car have indeed bellied out, which condition was drawn to my attention by the MoT tester last time I submitted the car for its annual going-over).

Pat suggested that I gently re-shape the access to the turret (ie widen it) with a couple of carefully wielded hammers - he thinks that, provided care is taken, this shouldn't compromise the strength of the turrets.

Interestingly, when I asked about his 750 race-car he said that, as they fit 2.25in internal diameter springs (the standard ones are 1.9in) they are obliged to widen the slots, which they achieve by angle-grinding a slot down the font faces of the turned-over 'lips' that act as the edges of the turret slots, then close up the gap they've thus created and weld it up so as to restore the strength to the turret. He did say that the chassis they use for racing are not galvanised, hence their ability to weld them.

Any observations on these thoughts before I start metal bashing?

[nebogipfel]

I agree, I would to leave the shrouds on ....... as they should be. The springs certainly benefit from the support. As far as I am aware OE struts always had them fitted mine certainly did.

I suspect the spring may well bow and chafe the aperture without the support of the shroud?

Surely it is only a very small part of the aperture which would need to be relieved (thinking about the angle of the dangle and all that) As suggested a tap with a hammer at the appropriate points would probably do it.


I agree about the gum ......... I'd have asked him to spit it out!