Lotus Elan

Experience of AVO shocks

PostPost by: 2tmike » Wed Nov 27, 2019 6:40 pm

The previous owner of my S4 fitted Avo coilovers front and rear supplied by Kelvedon together with springs and various other bits. Today I stripped out the passenger side suspension to check a few things and found that the shock body and piston were well out of alignment with quite a bit of wear to the shock body in one place where the spring has been in contact. Sighting along the shock and piston there's a noticable bow in the spring. I haven't checked the other side yet. I guess that these are fairly budget items but has anyone else seen this issue or could suggest a reason for it ?
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PostPost by: david.g.chapman » Wed Nov 27, 2019 6:57 pm

I have had front AVO shocks on my +2 for about 15 years and 50000 miles. They have been working fine, but I re-used the old springs, so maybe as a result the springs rub on the body of the shock absorber.

I mitigated this by fitting some large nylon cable ties around the spring coils in contact with the shock absorber. Friction and wear is much reduced and all still seems to be OK.

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PostPost by: tonyr27 » Thu Nov 28, 2019 2:41 pm

The AVO rear shocks on our S3 leave a lot to be desired. Had them rebuilt by them and are leaving again after1500 miles. Someone also said they don't dyno them so no matched pairs.
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PostPost by: 2tmike » Thu Nov 28, 2019 2:57 pm

Thanks both for the comments. I'm starting to think my problem is with the springs. When I back off the height adjusting collar to take all tension off the spring everything is fine and straight. As I wind the tension back on the bow start to appear in the line of the spring and with the shock adjusted for approx the right ride height it is noticably bowed and quite close to the shock body at the nearest point so no surprise that it rubs against the shock when driving. Maybe I'll use the cable tie trick short term but swap out for a better set up later.
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PostPost by: ElliottN » Thu Nov 28, 2019 6:32 pm

Can only endorse my + experience.
I have been running AVO front shocks on stock S4 for 3000+ miles and very happy. No wear, no ssues at all. I did have the springs made locally (in Oz) but to AVO recommended rates (firm road) for the car.
Having said that, I'd prob better put my specs on and check....
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PostPost by: RichardHawkins » Thu Nov 28, 2019 9:49 pm

Mike & Elliott,

I have just taken my front spring/damper assembly apart Lotus springs and Spax dampers I assembled them with the shrouds, these are like a baked bean tin with the end cut off and fitted over the top of the spring open end downwards. This assembly will not fit into the chassis front turrets as the opening in the new chassis is about 6mm smaller than the old chassis, that’s why I have taken the assembly apart. Without the shroud I can see the springs are obviously bowed. I have a set of old Lotus springs and dampers which I took apart to see if these old shrouds would fit? No they don’t, but the springs had been rubbing on the shrouds and dampers. Without the shrouds the springs are obviously bowed. I don’t know much about springs but I suspect that there is some sort of proportion of outside diameter to length such that if a short spring of large diameter is compressed it will not bend sideways, but our front springs are long and relatively small in diameter. One of the things that interests me is why Lotus world champion constructors at the time chose these springs. Does a one know?

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PostPost by: 512BB » Fri Nov 29, 2019 8:02 am

RH wrote ' This assembly will not fit into the chassis front turrets as the opening in the new chassis is about 6mm smaller than the old chassis'

Interested to learn about this Richard. What chassis is it , how old is it, who made it ??? I am sure people want to avoid buying a new chassis that is not to original spec. Do tell.

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PostPost by: alanr » Fri Nov 29, 2019 9:19 am

I too agree with others that the original shock absorber shrouds prevent and stop any spring bowing. I fitted Spax adjustables on the front of my +2 last winter and used the original Armstrong top collar, modified to fit,instead of the Spax top collar to enable fitment of the shrouds.
ready-for-fitment-to-car.jpg and


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PostPost by: seniorchristo » Fri Nov 29, 2019 3:07 pm

I have a similar problem with the front AVO's on my Elan and use the tie wrap method to avoid wear. Using the original front shrouds looks like a better solution. I may try this when I rebuild my front suspension. :)
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PostPost by: RichardHawkins » Fri Nov 29, 2019 9:20 pm

Leslie,

The chassis is Lotus Replacement. I bought it in 1979 in anticipation and concern about future availability. Life got in the way and I had to wait for retirement.

Since yesterday I have been trying to find any information about spring buckling. I found only one academic paper on the subject, and that suggested a ratio of the length being no more than 4 rimes the diameter.

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PostPost by: englishmaninwales » Fri Nov 29, 2019 9:59 pm

I’ve had variable quality and service from AVO.
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