Shock identity

[Eyetee]

As the title says can anyone identify these shocks, well actually I can tell you the camoflaged one in probable the origonal from 1971 TR6 or replacement standard part. The red one has an odd base bracket and no where for a bush and no markings. This isnt a test I dont have the answer, a pair were acquired and dont seem to be able to apply them to the job.

 

 

[Richard Crawley]

I recognise the original but not the new one; even the general appearance is not TR6 (or any other TR for that matter!). God & the supplier knows what they are for; those bottom pivoting fittings look overly complicated compared to the simple front wishbone arrangement on the 6.

 

If you take the **** off the bottom of the new one, they might be broadly similar but it’s impossible to tell from the photo if the extended & compressed length are suitable, let alone the damping rate. Are they gas? Are they adjustable? Why do you ask?

[JohnC]

Bottom one may be for a RevingtonTR rear telescopic conversion.

 

Cheers,

John

[RogerH]

Greetings Folks,

the bottom one is in deed for the Revington Damper in strut rear suspension mod - not for the feint hearted.

This mod is designed to put all the components in the right place but is quite an engineering feat. That lower bracket is rather clever and well made but one does need to attack the swinging arms to make them fit.

The dampers have quite a short stroke and make them useless for other applications on the TR rear end.

They do look very neat when installed but a lot of work. Not really for a road car.

 

Roger

[Eyetee]

Thank you gentlemen

 

They were acquired with a chasis that had previously been used for a rebuild that was sold prior to completion the new owner then went on a different tac clearing unwanted parts.

 

They are useful but not for a front shock

[david ferry]

Personally, I would fit them if you are even vaguely considering a rear shock modification to telescopic shocks from lever arms. This is in my opinion probably the best engineered conversion.

 

If you decide not to use them, I am sure you will be able to sell them. You may need to complete the package with any missing parts and fitting instructions.

 

Good luck

 

David

[Richard Crawley]

Interesting thread; now we all know what they are for, I would definitely fit them in faviour of those dreadful lever shocks. I believe converting to a telescopic rear end is probably the most effective single modification you can make to an IRS car.

[Jersey Royal]

Hi ,

Revington fitted that arrangemnt to my six, i have had no problems with road use. I havent driven a six with the standard system so cant compare. The car is very solid at the rear and corners very well indeed.

 

Guy

[Eyetee]

This afternoon inspected chasis and the bracket for the top of the shocks have already been fitted to the crossmember, so the shocks are perfect and are going to get used. Having read the link from JohnC the only thing to do is drill a hole through 30 year old alluminium trailing arms for damping adjusting.

 

ah hah but what shocks would best suit the front suspension?

[JohnC]

I'll be interested to know what you have to do to fit these to the rear end. I have a similarly designed modification, and I had to drill the trailing arm to bolt the annulus-shaped bracket to it. OTOH I haven't drilled an adjusting hole, as it's very easy to unbolt the lower bracket, extend the shock by hand, make the adjustment, and bolt up again. Don't even need to jack up the car if you don't mind grovelling around on the garage floor.

 

FWIW my mod uses SPAX made to a custom spec (available via their website). The travel available isn't much (~4" if I recall), but allows as much movement of the trailing arm as did the lever arm shocks.

 

I also use SPAX on the front end. In both cases they are adjusted approx mid-range, but that's a matter of personal preference.

 

Cheers,

John

[Richard Crawley]

I don’t have the Revington conversion but I also run Spax & haven’t had any problems or complaints since fitting; they can also be adjusted on the car. The settings I run are 7 on the front 5 on the rear but it’s easy to play around with them until you arrive at something that suits the tyres you have & personal driving preference.

[chrismitchell]

Also when you load the car up for a holiday its easy to stiffen the rear spaxs a few notches for the trip.

[RogerH]

Hi Folks,

just a bit of info when fitting this mod to the rear suspension. The lower bracket shown in the above photo needs to be positioned such that the lower attaching bolt through the bottom of the strut is parallel to the swinging arm pivot bolts and not at 90 degrees to the fore/aft car axis, otherwise the strut/damper will be constantly twisting as it goes up and down - fairly obvious but have you seen the Revington display model!!.

Eyetee - if your swinging arms already have the attachment holes drilled through make sure of the alignment.

The adjusting hole is a doddle, not worth not doing it.

The Revington OEM struts are by AVO and have the adjusters on the side.

If your top plates have been welded to the top of the spring attachment/cross member (as they should be) then you may find that the top of the strut attachment (threaded stud) may interfer with the body work !!!! best of luck on that one.

The OEM struts have a very short range, just adequate for the job, make sure they are fitted correctly otherwise they may both bottom out and top out giving an interesting ride.

 

The original screws supplied for attaching the lower brackets to the swinging arm were plain zinc/nickle coated steel It would be better to replace these with Stainless steel screws.

 

For the front end both Spax and Koni work well - Koni probably have the edge.

Best of luck - again, not for the feint hearted

 

Roger

[Richard Crawley]

RogerH; not sure who you are & you seem to be very knowledgeable about the Revington set up! The only thing I am slightly nervous about is your recommending the use of SS fixings. In this particular case, it probably doesn’t matter as it’s only the shock absorber location & the number of fixings involved almost certainly provides a more than a sufficient safety factor.

 

But I get very concerned that people who read about SS fixings & don’t know any better, start using them on stress critical components (sometimes with highly modified cars!) simply because they don’t corrode & they ‘look nice’. The (probably) natural assumption is they are stronger because there more expensive but they should never be used in stress critical applications as they just don’t have the strength!

[Tom Fremont]

I believe converting to a telescopic rear end is probably the most effective single modification you can make to an IRS car.

 

That's high praise, Richard. I've no complaints about my lever shocks but acknowledge that the telescopers have an impressive following .

 

A couple of questions:

 

1. Is the ride improvement due to increased stiffness, i.e. less absorption of road surface irregularities?

 

2. Is there a decent kit that doesn't require mods to the chassis or trailing arms ( i.e. holes or welding )? I prefer to keep things reversible when deviating from original.

 

I wonder if stiffer springs would yield similar results to a telescopic conversion, provided the lever shocks were in order .

[RogerH]

Hi Richard,

I'm a london group member, full name Roger Hogarth, and for my sins I inspect aircraft for cracks, corrosion etc using NDT methods, for the last 40 years (almost) at BA.

Your quite right about SS being 'good' because it keeps its shine. Most people do not appreciate what is going on inside the material when you start playing with it.

Regarding the damper attachment, the original setup used simple mild steel fasteners not high tensile. The reason being (I think) is that the tensile load going through the screws is damped by the damper so eliminating any shock load. I mentioned about ensuring that the damper does not bottom or top out, this could cause even a high tensile bolt to snap.

An interesting thing about high tensile steel is that they do not like corrosion and can fall foul of stress corrosion cracking which can cause the greatest lump of HT steel to suddenly snap. Horses for courses and all that.

 

Hi Tom,

1. don't know the technical answer to the theory for damper in spring but I know Revingtons believe in it.

2. There are a number of kits supplied that attach to the original dampers fixing holes and use Spax/Koni struts

very simple to fit and work very well - Tr Shop in Chiswick have a good kit

3. Stiffer springs will simply make you bounce higher and quicker - the damper controls the rate of bounce (sort of).

 

Roger

[Richard Crawley]

Hi Roger

I had an idea there might be a specialism lurking under there! I just wanted to emphasise the point for the sake of those, maybe, 'less enlightened' folk that read the forum. I get concerned sometimes because, as you say, most only see 'steel' as an all encompassing term without understanding the different qualities & applications the different types of steel are suited to; but why would they!

 

For my sins, I qualified as a mechanical Production Engineer around 35 years ago & so, like you, am probably one of a diminishing breed that understand this stuff. A few of my early years were spent in test & inspection for planned maintenance but on heavy engineering where the design F of S is probably 5 x what the aircraft industry work on; I also used to check for cracks & corrosion using (at the time) some fairly sophisticated ultrasonic & chemical testing kit; then moving into to detail mechanical design & greater things (or so I believed at the time!) in later life.

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Tom.

The biggest improvement with fitting a telescopic conversion is you can actually see over the bonnet (hood!) to see where you’re going when you dump the clutch; it will no longer feel like your competing with the space shuttle on getting into orbit! It keeps the back of the car firmly where it should be. You no longer get that horrible, vague feeling of lightness that goes with the massive weight transfer as the rear of the car squats & tries to burry itself into the tarmac while the front of the car almost tops out on suspension travel & it just makes the whole car much more responsive, predictable & even more pleasurable to drive.

 

The shock through spring method is the ideal method but due to some constraints on the original suspension design (i.e not much room), it’s not without some problems; it’s also a rather expensive option! For a road car, I would go for the latest 3 point bracket arrangement that bolts straight onto the lever shock brackets (as my 2 point does) & either Spax, Konis or whatever takes you fancy; the gas shocks also make a huge difference in updating the feel of the car; but I appreciate some may not want this! This arrangement does not require any chassis mods or holes & is so easy to fit it can be done in around an hour or so. As I said, I have Spax; they are a lot cheaper than Konis & can be adjusted on the car. I’m putting out a little more power than standard these days & have no complaints with them in the 3 years I’ve had them fitted.

Edited January 18, 2007 by Richard Crawley

[Roger H]

.....and for anyone that may be confused....RogerH is not me.....(Roger that...)

 

I have a space in my tag (which is sometimes representative of the space between my ears!)

 

Roger H

[jean]

So you are Roger Space Age makes quite a difference

[BrianC]

So you are Roger Space Age makes quite a difference

Jean, I seem to recall from long-ago schooldays that the French pronunciation of 'H' would be somewhat less flattering?l