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Shocking stuff

Posted: Tue May 20, 2008 3:23 am
by Kilroy
Yo all.
Not sure what to attribute a sudden frenzy of mechanical mayhem to - must be the onset of our winter causing me to try and get stuff shipshape - but then, things happen when they happen.
Sue had mentioned that her car was exhibiting some strange handling quirks - so at her request, we drove her car to a meeting last night - I suspect I wasn't responding quite soon enough...

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This car has been running faultlessly since returning from our running-in holiday last year. I must say, I havn't had a chance to drive it lately, as Sue uses it every day - but I wasn't expecting anything serious.
Jeez..!
The first thing that was very apparent, was the total lack of any rear shock absorbers.
Besides that - as we left the tunnel road, a smallish bump made the car veer quite violently to the right.
Horrors.
I was wondering if someone had nicked the shocks, but then the other behaviour had me very perplexed.
I drove it home after the meeting with considerable care in case anything serious took place.
This morning a quick glance under the car revealed all - both rear shocks snapped off..!

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I have a few spare sets, so I wasn't too worried about repairs - just mystified as to why it had happened. Sue hadn't managed to run over any JCB's of late - so why would a shock snap its mount off - let alone both of them.
The answer became clear as I fitted the first replacement - an identical unit - made in Australia. I couldn't get the threaded end into the mounting even at full compression.
I had the car supported by stands under the rear axle housing - so that I would be tightening the shock bushes in their normal position.
The car has been lowered by 2 inches, so the shocks run further up their stroke - but a quick measure up showed that in fact the shocks would bottom out before the suspension did.
I found a pair of English made shocks, and immediately noticed that they were shorter.
Aha..!
Obviously these Australian shocks should not be used in conjunction with lowered springs - but despite that - the shocks would still be the first thing to limit travel even when the standard ride height was present.
This would also explain why the back end has seemed to bottom out with such a sharp thud - instead of a more cushioned response from the rubber buffers - put there expressly for that purpose..!
This car also has the 4 leaf springs fitted, so it should be handling load better than its original 2 leaf items managed.

This is a new experience for me - and now I will have to check the other cars to see if any of them are in the same situation.
You can see these Australian shocks have uniform thickness bodies right to the lower mount - whereas the English units have a taper about 1 inch from the end - so they are easy to spot.

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Always new obstacles to overcome...

Cheers,
Kilroy

Oh - PS - I think the nasty steering glitch has been due to the broken rear shocks occasionally getting stuck between the axle housing and body - causing the back end to get pushed sideways. I'm about to go and test fly it, so we'll see...

Posted: Tue May 20, 2008 7:43 am
by MarinaCoupe
If Kilroy doesn't report back we'll know that there was a big problem.

Seriously though, the difference in the shock length would suggest that the Aussie cars rode higher off the road and the shocks were changed to suit.

From memory UK rear shocks have 6" of travel, what do the Aussie shocks have Kilroy?

Posted: Tue May 20, 2008 8:50 am
by ClaytonSpeed
I imagine that the Aussie cars would ride higher to help on the terrain over there. I have heard of rear shocks to snap on UK cars but only after a lot of rust and seizing.

My TC is lowered with 4 leaf springs and 2 inch blocks/Spax dampers and if anything it is under dampened and over sprung due to the 4 leaves.

As a side note I have re-angled the rear dampers by turning the top brackets around. This gives about a 40 degree angle instead of the standard 60 degrees. There does not seem to be any additional stress on the bottom plate in doing this as at first I thought it might push the mounting rod against the inner hole but not so. I have yet to trial this on SLK but may do the same trick on another car that is on the road. The method behind my madness was to effectively straighten up the rear dampers. It is easily reversible if it proved useless on the Island roads!

I hope you have solved your problems Kilroy! Good Luck!

Posted: Tue May 20, 2008 10:02 am
by ~Sam~
Another car on the road, so none of your then Ben :lol:

Kilroy I have to say I loved reading that especially the bit about running over a JCB :lol: Glad you have it all sorted out now though :)

Posted: Tue May 20, 2008 10:04 am
by ClaytonSpeed
~Sam~ wrote:Another car on the road, so none of your then Ben :lol:
Well no.. But I have a valid excuess!! :lol:

Posted: Tue May 20, 2008 12:51 pm
by ado28
Bloody hell Kilroy, the ride must have been terrible with they rear shocks or lack of them for that matter. My wife usually tells me that theres something wrong with her car when its too late but thats a modern piece of trash so it gets sent off to the dealers for them to put on their computer. I have tried to convince her to get a nice Marina as an everyday car but she wont listen and enjoys her modern crap that breaks down regular whereas I am happier when i'm driving my old classics knowing that my motoring costs are more than 2 thirds cheaper than the prat next to me in his nice shiny modern piece of junk and we both arrive at our destination the same way lol

Sean

Posted: Tue May 20, 2008 10:43 pm
by Kilroy
Hey guys - thanks for all the response..!

Firstly - the car is all sweetness and light - so it would seem my theories were correct.
Chris - my UK shocks have 5.75" travel, and the Aus ones 6" - but the Aus ones are 1/2" longer when fully compressed.
Ben - great idea about the top mounts - will try that myself - should improve the damping a little. I gave up on using blocks and had the springs reset - this was because I kept bending the shock mountings which were 2" closer to the ground - but of course - when you use blocks, the shocks remain at their normal ride height. No pain - no gain.!
Sam - just pleased you weren't annoyed from a female perspective.. :) and Sean - I'm used to being told when the slightest thing goes wrong - and I guess thats why I didn't initially place too much importance on Sue's comments about the handling - in future I shall..!

Cheers you lot,
Kilroy

Posted: Tue May 20, 2008 10:50 pm
by Uncle Frank
8) Hi Kilroy, that looked nasty..glad to hear you are ok mate, can you still get replacement shocks out there ok?, i have never seen anything quite like that...no wonder it was all over the place :roll: , BTW..will pm you soon, sorry for delay, i have some surprise news for you! :wink:

Posted: Tue May 20, 2008 10:56 pm
by JIM73
I had a new one snap on me while i was living in Portsmouth a few years back !! :(
And yes that is Portsmouth that stuffed Cardiff on the weekend !! :lol:

Posted: Wed May 21, 2008 1:47 pm
by Kilroy
Frank
Not sure if I can buy replacements here now - but as I have a few serviceable pairs on hand, it doesn't matter.
I suspect that the Australian made shocks are those fitted to Australian Marinas, and thus supplied as replacements suitable for UK Marinas.
News is - they're not..!
The Australian Marinas had an entirely different rear axle, so this may explain why they are a different length.
After all these years - we're still coming up with new problems.. :)
Makes ya feel special don't it..?
Surprise news sounds good.
You emigrating to New Zealand..?
Jim. I'm thinking that your post would almost make a good "Actress says to Bishop.." sorta joke - but I won't mention it.. :D

Nice to talk with you all.
Kilroy

Posted: Thu Jun 12, 2008 11:47 am
by dazza2623
When I inherited my Dads 6 I had a disturbing incident where by the Air Shocks He had fitted for towing (on a fast left hander at @ 120kph)steered Me on to the wrong side of the road almost colliding with a Semi.He had fitted them with a tee piece where the air would transfer from side to side.Hence when you go left it transfers air into left shock a gives you a nice push the other way.I fitted koni adjustable shocks soon after which were worth every penny.Still work as good as new 20 years on.

Posted: Thu Jun 12, 2008 12:19 pm
by RobChe
So...
I was thinking that I might be able to fit adjustable coilovers to the rear ?

I was thinking of keeping a leaf in place to act as a location bar and getting the coilover as upright as possible... Anyone tried this ?

Anyone got any good shots of the rear axle assembly ? Can't quite picture it... The pickup was a different beast !

Posted: Thu Jun 12, 2008 12:46 pm
by MarinaCoupe
Something that I just remembered about the rear shocks on my car when I bought it, before I changed to SPAX adjustables.

When I jacked her up, I couldn't get the offside shocker off the car as it had pressurised and pushed out to its' full extent all on its' own. I asked around and it was diagnosed that the internal valve had become blocked or collapsed or something and wasn't allowing the fluid through, effectively stiffening/locking the shocker to the Nth degree.

I had to dismantle the lower shock mounting off the leaf spring to release it (not wanting to saw the bottom pin through). Kilroy maybe this is what happened to your shocks, except your wife took a long time to notice and the bottom pins broke?

Posted: Fri Jun 13, 2008 8:08 am
by Kilroy
Chris
Hard to imagine both of them would have suffered the same fate..?
Can't rule it out though.
Must admit - the car in question appeared to have been off the road for a long time - so possibly a bit of oxidative stress...
Absolutely sweet now - and the occasional nasty thump that had been occurring (it seems..) has now gone.
I'll have to improve my means of translating the messages that arrive from the female point-of-view.
I make the mistake of assuming that the most important item being discussed is the rear-view mirror - for purposes of cosmetic application of course...
On the other hand - Sue really enjoys the looks her car gets - and having 2 litres of available means she can back up the looks when needed.. :)
It really is an enjoyable car to drive - and the performance of the auto seems positively snappy compared to some of the Japanese items I have sampled.
As a person who once thought that nothing short of a Ferrari would satisfy me - I gotta say that modified Marinas are definitely the go.
Amen.
Kilroy