iHenning

I just bought and installed a new set of leaf and shock absorbers. Both without lift.

The shocks are Skyjacker H7008. While driving and extending the shocks rapidly (potholes) there is a loud bang, like the shocks cannot extend fast enough and as a result the weight of the axel is jerked trough the body.

What did I do wrong?

my89xj

Did you get stock replacment shocks?

iHenning

I suppose so, 0" lift?

my89xj

I going to say if you got ones that are two long the shock would be smashing into itself

iHenning

They could bee to short, because it's while they are extending rapidly the "bang" sounds.

But a 1" deep hole shouldn't extend the shocks to the stop. And the leafs are stock replacements too.

And the shocks doesn't extend to full length by themselves, they are just neutral. I can push them to any extension and the stay there. The old stock shocks fully extended themselves.

my89xj

Why did you replace them if the old ones were still extending?

iHenning

Bought new leafs and shocks because they old set sagged.

Xj88

Shocks dont sag..coils do...but rarely

jtodaro

He didn't say coils. He said leafs.

wjnfirearms

One thing about your description of the problem puzzles me. As I'm way too familiar with potholes as I used to live in the pothole capitol of Pennsylvania, there's usually a compression of the shock, not extension. This being the case, if the shocks are bottoming out, then one might assume that there isn't enough travel in the shock tube (they're a bit short) or the leafs aren't the correct strength for the weight and structure of your vehicle. This would explain the banging you hear and likely feel. If the springs aren't the exact correct ones for your XJ, then they wouldn't be able to adequately support the weight of the vehicle and when you hit a hole, they allow too much travel of the vehicle and allow it to bottom out. The shocks won't be able to handle the hits if this is the case. If they are the correct ones, or beefier ones which isn't a bad idea as the rears on our vehicles should have been stronger to begin with, then if the shock tube travel is too short, the springs still will bottom out.

You need to check out both possibilities very carefully before you do some real damage.

wjnfirearms

Though there's some extension also, to make myself completely clear, you also need to make sure which is happening.

iHenning

Thanks for a extensive answer.

What I ment when I said extension of the shock was that whenever the axel drops quickly, but not far, I hear the bang. As when layers of new asphalt ends, and there is a few cm of drop down to the old asphalt. Whenever i hit a bump or any other obstacle that compresses the shocks, it's all normal.

So a pothole starts with a bang, and ends in a normal compression of the shocks.

Both shocks and leafs were bought on Morris4x4 as compatible and stock replacements for my XJ.

Xj88

If you read his comment it says he bought new leafs and shocks cause the old set sagged. It is still unclear why shocks we're changed in the first place

iHenning

I bough new shocks because I believed it would be a good idea.

wjnfirearms

Well, by my checking, you did buy the correct part number for the Skyjacker Hydro 7000 series shock, rear application. That obviously isn't the problem. I'd go with either an issue with the springs or the installation of them. No vehicle goes over potholes quietly or comfortably, but if it is that much of an issue as you seem to believe it is, I'd look more closely here.

And as to why the shocks were changed, if I did that much refurbishing to the suspension and the shocks had any years on them, I'd have likely done the same thing.

A lot of people like Skyjacker, but all of the "so called" good shocks are not. I had put EBCs on my '97 and they didn't hold up at all. They are supposed to be good shocks. I'm putting Monroe Severe Duty ones on my '98 now. They are the ones specified for the police package XJs.