Shock absorber replacement

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Rear shock absorber replacement [dapinky method]

This is a proven method to replace the rear shock absorbers on a UK Elan SE. It might work on other models but is not proven.

Taking the rear shocks out is a simple process:

  • Chock the front wheels and loosen the rear wheel nuts. Jack up the car and support it using the Jacking Points so that the rear suspension is hanging under its own weight. Remove the rear wheel.
  • Remove the 3 x 13mm nuts which are hiding under the plastic cover under the carpet in the boot at the top of the shock - DO NOT UNDO THE 14 MM NUT IN THE CENTRE - IT'S UNDER SPRING TENSION AT THE MOMENT.
  • From the wheel arch, undo the 19mm nylock nut / bolt through the bottom of the shock.
  • The whole spring/damper assembly will now come out (on the O/S [US=RHS] the exhaust gets in the way a bit, and on the N/S [US=LHS] be careful of the petrol tank) - but they will manoeuvre quite easily.
  • I've not looked at standard shocks, but I assume that the spring will still be a bit tensioned, so you will need to use spring clamps to compress the spring a bit to allow you to undo the 14mm bolt at the top, lifting the top plate then spring off the shock.
  • You will probably have to find some way of stopping the centre shaft of the shock from turning with the nut (be careful not to damage his shaft with molegrips (obviously more important on the new ones rather than the old ones).

As any Haynes manual will tell you, replacement is the reverse procedure to removal..................

  • If you have adjustable height shocks on at the moment, you can release the spring tension by winding the collar down the shock to avoid using spring clamps.
  • When re-fitting, put the top in first and put a couple of nuts on to hold it in place, then hold the wishbone down to slide the bottom mount into position - finger tighten the bolt only, at this stage.
  • Replace the wheel and drop the car down so it is at normal road height, tighten up the top 3 x 13mm nuts (only about 22 lb.ft), making sure the washers are flush with the bracket, not caught on the rubber/foam bits (It'll make sense when you look at it inside the boot!). Tighten up the 14mm central nut, torque up the bottom bolt to 50 lb.ft. This can be a bit awkward, I found that by using a 5" and a 3" extension bar you can just get a torque wrench between the front of the wheel and the arch, and still get a swing on the wrench. It is easier if you have an assistant to hold a spanner on the bolt, but if you've got ape arms, you can reach round the wheel to hold it in place on your own (or through the wheel if you've got thin arms).
  • If you go for adjustable dampers, my advise is to drop the bottom mounting to its lowest setting and 'shorten' the shock, making it easier to replace - then winding the plate up to the required position (I found that the best place as a starter setting was when the spring was just under tension on full travel, but you may find different!).
  • Re-tighten the wheel bolts to 59 lb.ft.
  • When both sides are done, make sure that the shock heights are the same by measuring the exposed thread below the spring plate and the end of the threaded portion, and that both shocks have the same 'hardness' setting.
  • (On my Pro-Techs, there is 3 1/4" of thread below the plate, and they are set to 4 clicks down from the hardest setting - but I'll have a fiddle with them as I go, to get the sort of ride I want).
  • A garage will be able to set up each shock to give a balanced ride using a 'corner weight' gauge (basically 4 sets of bathroom scales), but if you are using standard ones, this isn't an issue.

I changed mine recently and I spent about 3 hours on the job, this included cleaning and painting the top mounting plates and springs with a coat of black Hammerite, also adjusting the rear wheel bearings whilst it was all apart.

Just swapping over the shocks should be about an hour a side, but if you do it yourself, you'll probably end up with a paintbrush out somewhere along the way - Project Creep Lives!!!

It is probably a good time to give the rear suspension/chassis a spray of Waxoyl - but then it becomes a longer job - I didn't bother this time, as I'm going to replace the wishbones this summer anyway.

It's not a difficult job, just be wary of springs under tension!