Shock Absorbers

Method used by my garage:

Soak nut in WD40, brace damper by holding it tight with one hand to stop it rotating and repeatedly zap the nut with a suitable compressed air socket. they usually pop off after a few tries.

On or around Fri, 06 Feb 2004 14:53:06 +0000, JD enlightened us thusly:

that's what I did on the disco ones. Helps if you know the existing dampers[1] are scrap, as a big enough pipe wrench (18" one or bigger, I expect) to hold the f***er still will likely distort it and may stop it working right. But the technique worked for me. That and a decent 6-point socket to fit the nut.

I'd try 2, then if you're not worried about putting them back on again, try

David

Use a pipe wrench on the body of the shock absorber after soaking in penetrating oil or diesel) JD

I couldn't agree with you more Austin, but I'm always reluctant to point that out as it sounds soooo pedantic! :)

I agree with your argument, but anyone know why are they called shock absorbers?

Hey you too;)... I'm (pedantic) ^2 ;))

I believe a shock absorber is an engineering system consisting of (at it most basic) a connected damper and spring, so that as you said, the damper 'tunes out' undesirable frequencies in the system.

Thus, springs *are not* shock absorbers. Spring is both an engineering word, as well as a word non mechie people use. Springs are springs... nothing else: a base Mechanical Engineering construct that can store (and release) energy. Dampers, with no non mechie equivalent, absorb energy usually in the form of heat and fluid displacement.

A car travelling down the road is typically modelled as four 'spring-mass-damper' systems that each uses well understood (but very complex) differential equations. To perform these calculations by hand (or slide rule), these equations are most often approximated by the use of Laplace Transforms to model more solvable linear equations. These days however, the spring, as well as the damper, are modelled in 3D Finite Element packages (google ProEngineer) and the whole system can be modelled 'virtually'.

hope this is clear, it *is* meant to be helpful.

Tom

Going to play with the rangie this weekend: keep raining = more mud = very good weekend

Yes it's clear, but it didn't tell me anything I didn't already know.

In article , Paul S. Brown writes

If you are changing the dampers then this option is the most effective.

Gently heating the nut until it just glows cherry red will not damage the mount on the axle one bit. but the rubbers will be history but you don't need the old ones anyway. The nut will come off as if it were finger tight....but dont try it with your fingers ;-)

It is always important to watch where your "unused" bits of flame are pointing.

This is probably the quickest option...

I use a nylon strap (small tie down/ratchet strap) when I do it - works every time and locks the shoccker solid. Fold the strap in half, feed the looped end around the shock absorber, put the ends of the strap through the looped end and pull tight. The direction you put the loop around the shock absorber is important but you'll know if you've got it the wrong way round ! (the loop should go round in the direction opposite to the direction you want to stop it moving in...)

Wrap/tie the ends of the strap around something solid nearby and it will lock the shock absorber in place so you can use both hands on the breaker bar. If you want more grip then put some slack in the strap and wind it onto the shock abosrber by turning the nut. Once you have a few turns around the shock absorber, the harder you pull on the breaker bar, the tighter the strap will grip.

It is possible to shear the nut off using this technique and I've never damaged the shock absorber body while doing it.

cheers

Dave W.