Bilstein damper's come apart!

[DuncanK]

Unusual failure(?): The top mount of my off side front Bilstein damper has come unscrewed from the damper rod, resulting in spring and damper dropping down and pushing in the side of the bodywork. ☹️

 

See pics here link should now work!

 

Fortunately it happened at low speed (while taking a friend out for a quick taste of how much fun 7s can be! - Last time I did that, the HG failed! )

 

Any ideas what caused this? I guess there's nothing to stop the damper rod rotating and gradually unscrewing, but I've never heard of it happening.

 

Having said that, now that it's happened, I'm pretty sure it's happened before on this car, as when I bought it I noticed repairs to the flared wing in exactly the place that it contacted the tyre when the damper failed, and there was slight existing bodywork damage around the spring damper area.

 

Need to get this fixed quick as we're off on a Grand European Tour in 2 weeks time! I've managed to free off lower damper bolt, although I've chewed the head a bit. Questions are:

 

1. If I remove lower bolt how much compression is there still in the spring?

2. What's best way to unscrew upper damper mount (it's 95 de-dion car with 'all in one' long 3/8" upper mount bolt. All I've got is an allen key!

3. Once damper is off, if I screw upper mount back onto rod, with loctite, will this be a permanent fix? Is there supposed to be a lock nut?

 

Any advice welcomed!

Cheers,

Duncan

 

M7JVL

1.4K with clamshells

(Sheep-liker's 'other half'!)

 

 

Edited by - DuncanK on 22 Jul 2005 23:04:11

[Bob Corb]

1. Plenty, ideally use a spring compressor (I've used cargo straps in the past but I DONT ADVISE THIS METHOD)

2. Possibly if you put a bit of tubing over the end of the allen key to extend it a bit (they aren't that tight)

3. On the shaft you should have a rubber bump stop then a nut then the upper platform centre piece (big washer) followed by the upper mount. Loctite in the thread wind on hand tight and then using one large wrench on the top mount and a spanner on the lock nut torque them together firmly. (I dont have any torque values but I dont know how youd measure it anyway?

 

Good luck

[DuncanK]

Hi Bob,

Yes, I trawled through the techtalk archives and came across your comments about changing springs without a compressor.

 

With the front of the car jacked up, the spring that is ok is about 177mm long (including the retaining plates). On the side that's come apart its more like 188-195mm (depending where you measure since it's bending round where it's pushing against the body).

 

Any idea how long a completely unrestrained spring is? I'm assuming they're standard original 1995 ones.

 

I guess I'm going to have to use a spring compressor to get it back together anyway though so I might as well get one to take it apart.

 

Duncan

 

M7JVL

1.4K with clamshells

(Sheep-liker's 'other half'!)

[Bob Corb]

Off the top of my head I think about 20mm more? They def have a lot of force them...

[SimonRHC]

Be careful these springs are leathal!

even if it's 150 lb/inch with 1 inch compression you could loose fingers.

My advice is treat them like un-exploded bombs.

 

when i compressed my springs recently i used very heavy duty cable ties.

they are avalible from RS and useually state their breaking strain so you can work out how many you need then add some more to be safe.

 

as for screwing the damper rod back in,

to avoid it coming apart use some thread lock, they seem to have it fitted when new.

I nick it from work but some one will help you find out where it's sold.

cheer

Simon

[_Tim_]

Just to echo what others have said - please be careful with those springs!

 

I had my two standard billys apart to replace the springs earlier in the year, and rigged up a home made compressor with some ratchet straps and a workbench - I had a hell of a sweat on I can tell you, I wouldn't do it again!

 

- Tim

 

Caterham 7 - BMW E30 M3 - Nissan Navara

[Sheds Moderator]

Yet another warning re springs.

 

DO NOT P*SS ABOUT WITH SPRINGS

 

Always use an appropriate tool. If you are confident in being able to develop your own, well and good. DO NOT bodge up something that you think might work.

 

A friend of mine had to have surgery to repair his broken and lacerated arm after a car spring savaged it during home maintenance. He's a manager in a vehicle repair shop so he should have known better.

 

I have heard another tale where a compressed spring, bound up in compressors, was placed on an oil drum while the mechanic carried on working. The thing rolled off the drum, hit the deck, jumped out of the clamps and punched a hole in a wall.

 

As posted above treat them as you would a loaded gun. They are no less lethal.

[Kathryn]

Thanks all for your advice. We are definitely going to take the car to Caterham (she's going for a service next week anyway, prior to our Grand Trip) for them to look at the springs etc. We will stand a fair distance away...

 

We'll update once there is more news!

 

I like sheep

[Kathryn]

UPDATE

 

She's back, and ready to be taken on holiday. We took her to Steve Parker at Stansted in the end, and he fitted new dampers both sides and serviced her. Thank you Steve!

 

We are now packing!

 

Kathryn

 

I like sheep