New Front Dampers

[PeterDavisX300]

I have just fitted a new pair of Front-Shocks, KYB. I chose KYB because I was told they were a little softer than Monroes or Bilsteins, and I already have a fairly new pair of KYB's on the rear. What I couldn't find was how tight do I screw the nut down on the top to compress the bushes, it's quite hard down at the moment, and there doesn't seem to be much bounce at the front, although the shocks I took off, were, "Shocking" if you'll pardon the pun. I've compressed the rubber bushes to about a third of their original thickness, and put the second 'Lock-Nut' on. The car definitely feels better and more direct with much less 'dive' when braking, but it does feel a bit hard at the front and doesn't bounce the same as the rear. I also put new 'drop-links' on.

So if anyone can give me absolute direction on this, I'd appreciate it. Naturally all the bolts were finally tightened with the car weight on. There was absolutely no guidance from KYB themselves.

Thanks, Peter

[pimgmx]

Steve,
I just had a look in the Jag workshop manual, these are the torque values for the front shockers:

• * shock absorber to lower mounting: 61-68 N/m
  (the bush on the lower wishbone)
  * shock absorber to upper mounting: 35-43 N/m
  (the one damped by those 'foam' bushes)

[Brakebuster]

i think you will find a spacer tube on the damper strut that the foam sits around,
the shaped washers fit either side of this and the nut tightens onto the washer until the spacer makes it tighten onto something ,so the foam does not get over compressed

and then use the above settings for tightness

the distance between the car body and the damper foam bushes to special washers is a set distance, and will not affect ride comfort unless a different material is used ,

these foam spacers reduce the amount of vibration transmitted to the body , this reduces both noise and ' thump' feel

BB

[PeterDavisX300]

Aha yes. But, my new dampers are KYB and don't have the 'Spacer' facility. The rod of the damper is already the same diameter of the O/D of the spacer, and the 'Rubber' spacers barely push over the rod. What you get is Four large washers, the two thinner washers have lips on them that each protrude into the thickness of the body-mounting, so they are either side of the hole in the bodywork. Then the strong 'Rubber' bushes are either side of them, then a thicker (about 4mm thick) washer goes on the other side of the 'Rubber' bush, the lower one baring down on the shroud of the damper, the upper one has the top of the rod screw end baring up against the top nut which is not nylock but has a thinner locking nut. It's really just how much those strong rubber bushes should be compressed ?

[Brakebuster]

the trouble with buying aftermarket items i suppose, they are not made in the same way or style from OEM sometimes

so you need to contact KYB for advice

BB

[PeterDavisX300]

Yes, I did that. KYB say that from what I have described I have mounted the Dampers correctly, and there is no torque setting for the top-bolt when 'squashing' the strong-rubber-washers. The rubbers should be squashed beyond half their thickness, and should be larger in diameter than the washers either side. You need to also test that the top shroud is really secure on the underside of the bodywork. I also went on to an American site and finally found another thread that said about the same. I asked KYB about how firm the shocks are, they said that would settle-down fairly quickly, and in fact they feel a bit better after about 40 miles. I'm happier now.

Hth, Peter

[PeterDavisX300]

Short update. The dampers feel a lot better now. They seem to be soft-enough to iron-out bumps, but hard-enough to have greatly reduced 'dive' under heavy braking. Quite happy with the performance now. Just a wee footnote, I did pump the dampers a good few times before fitting them, despite the lack of any instructions and KYB saying they thought that unnecessary.
Peter