Removing Suspension "Top Hat"

[Jeemy]

Bouyed up by Rip's comment that a stupid question is the one you don't ask before you wreck something, can I get an opinion on this before I do it?

Swapping out the stock shocks for a Gaz set. The 'top hat' needs re-used.

I don't know how strong this piece is. The central locator bolt has 2 flat sides. Gripping this with mole grips will not break the hold. The springs are held with compressors.

So I planned to take the whole unit into town, and put the 'top hat' in my bench-mounted vice. Thing is, I suspect the bolt I need to remove will still spin. I think I need a good way of holding the bolt, to spin the nut. Not the top hat at all….

How does one free the bolt in the picture? Stick the whole thing in the vice upside down, grip the central locating bolt, have somebody hold it balanced, and pull the nut? I would like the shock to remain usable for anybody who needs it….

[dapinky]

Jamie,

from the picture, it looks like the spring compressors aren't tightened enough to take the pressure off the top plate - this has the effect of adding tension to the bolt you need to undo.

If you wind them down equally until there is no pressure on the plate (and the centre shaft of the shock is free to rotate in the body), then the nut should undo with the flat bit held still (open ended spanner or place in a vice).

The Spring will need to be compressed to that stage anyway to enable them to fit over the new shocks and still get the top plate onto the centre shaft.

I can't remember the exact torque figures for the centre nut, but it shouldn't be too tight to undo with simple hand tools.

I can't tell from your picture, but it will be either a single nylock nut, or maybe 2 plain nuts locked together to hold, in which case, completely remove the top one first to unlock the joint.

[Jeemy]

Bench vice sorted it. The springs were fine, its not a great picture but they were well away from the hat. I gripped the piece just below the single nut in the vice and it came off with not too much effort. So thats the shock dissassembled, next task is to locate replacement boots, and get the second brake line connection and wishbone off, following removal of the bushings from this, then I am going to send it to be hot zinc dipped. During that time I can rebuild the rear brake caliper and brake lines and clean up the rear arch, it should be sparkling when finished!

I'll post pics on my thread in due course, have of course taken loads for anybody wishing to see them and reference for myself putting it all back together....

[Jeemy]

Really struggling on the boots / gaiters / dust covers. Demon Tweeks do a 'universal' set with bump stops. Nothing on eBay, very little info on the internet apart from bike fork gaiters. This implies that they either come with the suspension, or don't, in the latter case they are not required.

I'd have thought if bump stops were needed for safe operation, Gaz would have included them in the package. Cliff has pics of his Gaz shocks fitted without gaiters at all.

So I've asked him if there was a reasoning behind this and will try to give Gaz a call too, as I don't really want to pay £32.50 per pair to DT when the bump stops might not be wanted.

All I can do for now when I come to fit them is set them up to have the roughly same ride height as the originals. Mine really seemed to sit incredibly high compared to other cars I've seen so I will probably end up lowering this, but once all corners are done I can work on getting the ride height comparable to the manual recommendations.

One should be able to apply the spring compressors and then just spin the lower hat into position. My air tools are still stuck in town, but once I get my van back and can bring the compressor up, this should be an easy and safe adjustment to make with an air wrench.

[dapinky]

The gaiters are listed under part number A100C6013H - £15 each at SJ's.......

.......not sure about GAZ shocks, but my AVOs have bump stops fitted (and gaiters)

[Jeemy]

Cliffs called Gaz, and apparently they dont need them. I will look to see if they already have bump stops, and might fit them if not just to be on the safe side.

[Jeemy]

That works out about the same, £75-80 the set with VAT & shipping.

I think I'd prefer gaiters, my springs are black so it would be nice to get coloured ones but I can't find anything online at all. So I need to look and see if there are bump stops; there must be....

[Rusty Wishbone]

I've recently been through this myself. I bought a pair of gaiters from SJ Sportscars which I didn't use on the Gaz dampers. You are welcome to take them off my hands for a few quid, although they don't engage with the Gaz dampers as they do with the original ones. The bottom end of the gaiters have a depression which engages in a corresponding depression in the original damper. Personally I am happy not to put the gaiter on.

I was, personally, disappointed with the instructions that came with the Gaz dampers. They were of very little use to me, but then I suppose they are aimed at the professional mechanic market rather than the enthusiastic amateur. They do say something about checking the bump stops, but without any information on how that check is made. They said nothing about the fact that gaiters are not required.

Send me a PM if you are interested in the gaiters.

[Jeemy]

Thanks RW. I was rather under the impression that any fit would be pretty useless on the Gaz so I have tried a punt on a pair of universal boots which seem to measure up the same (from memory 8cm inner diameter and 20cm long) as the originals and were cheap, just to see how they fit up on the Gaz. If they don't fit or I am not happy I shall probably leave it.

I don't think I even got instructions with them, just an analysis of their performance on a graph and some disclaimers. I haven't had time to get back to the unit look.

[Rusty Wishbone]

After repeated measuring of ride height, here is the position of the bottom spring seat on the adjustable Gaz dampers. I'm using new springs from SJ's. Are yours in about the same kind of position?



Did you make any changes to the bump stop?

[cliff]

Apart from not noticing the gaiters until Jamie mentioned them

I measured the distance between the top hat and the lower spring seat on the original shocks when I took them off the car.

CIMG1699.jpg

Not the originals but you get the idea. (Pre production without gaiters!)

P1130280.jpg

Then used this as a base measurement which could be adjusted when I had the geometry check and corner weights done.

P2080021.jpg

I don't think the bump stops are adjustable, if they are the I was happy to leave them as GAZ had set them up.

Hope this helps. Having read Jamies amazing thread, I realize that I should have gone into more detail about my suspension rebuild. I will try to add some more when I get time.

[cliff]

A bit late, but removing the top hat is quite easy. Use the spring compressors as Jamie has done in the picture, there doesn't need to be too much tension on them but enough to stop the spring from moving when you release the nut.

Hold the flat surface at the top of the shock with a suitable spanner and carefully remove the centre securing nut.

PC150233.jpg

Not the best picture but gives an idea of the length of the thread.

Last but not least, very carefully release the tension from the springs, dispose of or reuse as required.

Examine the top hats carefully, one of mine looked like this:

PC150239.jpg

The rubber was pretty bad as well, the new one there for comparison.

PC150241.jpg