Thread: Issue with new rear suspension

Is it the spring rebounding or the tyre sidewall ?

People, including some engineers forget there are two springs at work on any car, the suspension spring and the tyre, luckily tyres are pretty good at self damping.

Which Billies and what rate spring ?
If it is the spring you don't have enough rebound valving, pretty common in a 130.
You can have yours re-valved, adding another set works but you'll have a lot of low speed bump, it'll cut initial body roll to almost nothing but will make the ride harsh.

If it's a combination of tyre and spring you may have hit a critical frequency where the natural tyre rate and spring rate frequencies are in synch, but it's unusual.

Andrew

I have a similar issue with my 98 D1. Although my cause is sacked out Rancho shocks not coping with the heavy duty springs and airbag combination.

Whilst you're looking at the TerraFirma catalog, what would you think about the remote reservoir shock and it's ability to cope with the rear setup you have (which is similar to mine)?

My options are either the big bore expedition or the remote reservoir items (in terms of TerraFirma), as next year we will be setting off with a tonne of camper trailer and 2 and half tonne of loaded D1 across kms and kms of corrugations out west.

Regards

Ian

What model shocks are they? std ones will top out easily with a 2" lift...

Just out of interest did you bleed the shocks before fitting them?

That is fully compress and decompress the shocks 5 - 10 times or until that are damping correctly before installation.

Just an idea.

Originally Posted by MinniTheMoocha

Just out of interest did you bleed the shocks before fitting them?

That is fully compress and decompress the shocks 5 - 10 times or until that are damping correctly before installation.

Just an idea.

Don't need to do that on a Billie or any mono-tube damper, you only need to do that on a twin tube.

Originally Posted by 86mud

Hi all

I recently installed Dobinson 2" lift HD coils and matching Bilstein shocks in my 1998 130 HCPU 300 tdi.

In the rear I also installed polyair bags.

Now when I go over large bumps (for example a speed bump) at speed, the rear springs seem to continue bouncing after going over the bump (polyair bags are at minimal pressure - 5psi).

It is as though the rear bilstein's are not big enough (capacity) to handle the energy of the spring.

Alternatives? Do I go a larger bore shock (like Terrafirma Expedition) or do I go twin rear shock set up using another set of Bilstein's?

I have the Terrafirma catalogue in front of me...which is bad for my credit card!

Cheers
Andrew

Hi, I reckon that you cant go past Dobinsons shocks as they lasted over 6yrs on my old 80 series Cruiser towing a 23ft van and offroad work. They may not be to everyones liking, but I think you will like them. Bob

It's definately the spring rebounding and not the tyre.

I will have a look tonight at the model number on the Bilsteins. There are not the standard ones. When I installed them, their extended length matched the 2"+ spring perfectly.

In my old rangie I had the 3" flexi coils from Dobinsons and Procomp shocks and never had a problem, but the rear of the Defender is totally different and size of wire on the rear springs is pretty huge.

I still have the rear old shocks at home. I might put them back in as a trial. They were EFS brand from a nissan GQ (larger diameter then the Bilsteins) which had been modified with a eye at the top. The top shock mounts on the chassis were also extended 40mm up higher.

Cheers
Andrew

Originally Posted by 86mud

[snip]
(larger diameter then the Bilsteins)
[snip]
Cheers
Andrew

But probably only had 33-35mm diameter pistons, a 51-6100 series Bilstein uses a 46mm piston

You can't really deduce anything from OD's when comparing a twin tube to a mono-tube.