MOT Passed but a note on the Strutts

[H823ENM]

I could do with a bit of advice regarding the Mcpherson Strutts on my 91 S2, I've just had an MOT, which cost £56.13 for the ticket, wiper and a new bulb, so thats all good. However I have for the second year running been pulled up on movement to the offside Strutt (is that with one or two t's), can anyone tell me if this is something to get worked up about or can i leave it a while, plus any suggestions on repair/replacements, I remember seeing something in 911&porsche world but I'd rather not try anything too techy without some close help.

thanks

Martin

 

[Diver944]

At some point you will get an MOT failure due to excess play in the strut (it happened to me a few years ago but I didn't have two years of warnings [8|]). New struts are about £150 each from Bert at www.berlyn-services.co.uk and will need a few labours to fit followed by a proper realignment as the caster, camber and toe will have been knocked out of line whilst fitting

 

[Diver944]

An alternative is the Koni Sport shock insert at £102 from http://www.motorsportworld.co.uk/

This will need you old strut to be cut and the fluid drained out before allowing the insert to be fitted inside the original strut

 

[zcacogp]

ORIGINAL: Diver944

An alternative is the Koni Sport shock insert at £102 from http://www.motorsportworld.co.uk/

This will need you old strut to be cut and the fluid drained out before allowing the insert to be fitted inside the original strut

... and the original strut welded up, presumably?


Oli.

 

[Diver944]

No, the insert bolts through the bottom of the original casing (IIRC you have to drill a hole for this)

 

[rcsalmons]

Correct me if I am wrong but surely if you had movement in the strut it would be leaking and an MOT failure - perhaps they mean the top mount?

Rich

 

[sawood12]

No, 944 struts never seem to leak. The mechanical wear over the years creates play within the strut which is the play observed. I'd had a couple of advisories on mine before I changed them. This is a bit of a bug bear of mine. Althought it is a testiment to Porsche's robust design philosophy things like shock absorbers should be designed to have a limited life to prompt the owner to replace them. As it is we have cars knocking on the door of 20yrs old some of which are still fitted with their original shock absorbers that keep on soldiering on passing MOT's. As you can imagine they are way past their best, but worse than that, they are simply dangerous. Shock absorbers should really be replaced every 5 yrs to keep them in tip top condition. I always liken it to brake fluid. You'd never dream of not replacing your break fluid less frequently than 2yrs. Just imagine the state of the oil in your shock absorber after 20yrs.

 

[Paul Fraser]

I'd ask the tester where the play was. I don't really follow the thread above. I have replaced three pairs of shock inserts over the last couple of years on three cars all 20+ years old and none had play of the insert in the shock and I can't really see how this would happen. The insert is held in place by the brass coloured top cap so there shouldn't be any vertical motion, and I would imagine circular travel is minimal. The inserts I took out didn't have any obvious signs of wear, and, as a couple of them had burst/were dripping oil would have lubricated any motion anyway. I am talking about standard shocks here and not, as I suspect above, some type of sport shock, Konis?

 

[sawood12]

The play is with the silver plunger (for want of a better description) within the strut as the internal wear. I have no idea why they don't or rarely leak, but the silver plunger develops play.

 

[Paul Fraser]

OK Scott, thanks for that, I understand now.

 

[zcacogp]

ORIGINAL: Diver944

No, the insert bolts through the bottom of the original casing (IIRC you have to drill a hole for this)

Paul,

It sounds like you have the knowledge to answer the question I have been wondering out for some time now ... I am looking to change the suspension on my '89 S2, and need to know whether to buy replacement struts or inserts. Fitting new struts is obviously an easy job, but how hard (or indeed how possible) is it to fit new inserts into the struts?

You talk about cutting the struts to get the old inserts out - what needs cutting? I am imagining that it is cutting around the tube which the insert sits in ... but how does the new insert bolt into the old strut?

Does anyone have any pictures? Buying inserts will save a packet, but are they impossible for a keen home DIY'er mechanic to fit?


Oli.

 

[Diver944]

www.paragon-products.com have a useful page showing pictorial instructions in their suspension section but the link to the pics seems to be broken at the moment []. It looks fairly straightforward.

0.5 Paint your old strut Koni yellow for bling effect
1. Cut the strut just below the crimp (accurate measuring is needed)
2. Remove the piston and drain out the fluid
3. Drill a hole in the bottom of the strut (accurate measuring again)
4. Insert the insert into the casing and secure with bolt through the hole you drilled
5. Fit a big rubber cover (supplied) over the jagged edges you cut.

They do an exchange service if you don't fancy it yourself and can also fit adjustable spring perches for uprated springs at the same time. I'm sure I heard that Jon M can do the same thing (but could be wrong)

 

[hartge bob]

Paul,

Working from memory here but,

I think you drill a hole in the bottom of the old strut first to relieve the pressure, before hacking the top off the strut.

I'm sure the Paragon article mentioned something about oil blast radius of several feet when the hole is drilled.

 

[zcacogp]

Thanks ... have hunted the paragon site fairly extensively but can't see that link at the moment!

Is the link down, or the link to the pictures down? (If the link exists, could you post it up here - thanks!)


Oli.

 

[Diver944]

This is the link to the actual inserts:

http://www.paragon-products.com/product_p/koni-8641-1414s.htm

Half way down that page is a link to the 'detailed instructions' but it throws up an error at the moment []

 

[zcacogp]

Paul,

Thanks - helpful.


Oli.

 

[zcacogp]

Well, hey, a quick eMail to sales@paragon produced a very friendly reply from someone called Jason Burkett. Here is the 'good' link:

http://web.archive.org/web/20041118105638/www.tech-session.com/kb/index.php?page=index_v2&id=69&c=4

A question ... looking at this, once the strut is split, there is nothing left to hold the top of the insert in. It just as the rubber sock arrangement keeping it in place. OK, it is held in with a hefty bolt at the bottom, but what keeps it vertical in the strut? Anything?

It just all seems a bit prone to flexing and wobbling.

And what happens to the pressurised oil that surrounds the insert originally? OK, it falls on the floor and is trod into your carpets, but there is no way of replacing it for the new insert, and even if you did then there is no way of keeping it in (so to speak.)

Is this really as good as the original set-up, or is it a cheap aftermarket 'botch'? (I use the 'b' word with care.)


Oli.

 

[sawood12]

The standard struts are sealed units and don't have inserts. The principle is when you cut the top off the strut all the oil and internals of the shock absorber can be removed leaving an empty cylindrical shell. Once you've drilled the hole in the bottom of the strut and cut the strut casing to length the new insert slides in. The lateral support comes from the fact the insert is a good fit inside the cylindrical shell and the bottom bolt is obviously (I hope) strong enough to contain the force generated in within the shock absorber. I have no idea how robust a solution this is but it seems to be OK as i've not heard of any reports of any failing.

 

[zcacogp]

OK, thanks. Given the saving to be made, I think this is the route I'll take. But I may just buy some scrap struts to do the fitting in the weekday evenings, so I can have ready-prepared units to bolt on to the car when I do the job proper.

Thanks for your help.

So, if I am choosing inserts rather than struts, the cash will go a bit further and I have more choice. Which inserts to go for? Boge/Sachs, Koni or Bilstein? (Are Bilsteins rock-hard, or are they comparable with stock?)


Oli.

 

[H823ENM]

Thanks for the response guys, sounds like I have a lot of catching up to do, I'll be checking out the Paragon website at the weekend and seeing if it's something to take on. I'm very interested in the exchange idea though.