Caravan shock absorbers

Warren-Pat_01 · Guru

Caravan shock absorbers

Rob Driver · Guru

Hi Warren,

I would not just buy any old shock absorber but would source one that is suitable for your suspension.
Shock absorbers come with many different specifications.
The shocky that is good for a coil spring may not be suitable for a single axle leaf spring.
The coil has no friction and the leaf spring has differing friction rates when compressing as opposed extending.

A common specification on a shock absorber might be Compression 80% Opening to 20% Closing.
This variation in Specs needs to be matched to your leaf springs and the weight of your van.The shocky does not carry weight but the weight may be a factor when considering spring rebound and recovery rates.

The advice of a suspension workshop would be helpful with the shock absorber rates of compression and extension that may best suit your van.
A rough guide might be 80% opening and 20% closing and this would work and be an improvement but may not be the optimum specification for your van.
Length and mounts also factor in your selection.

I hope this is easy to understand. I would look for advice from a company like Pedders or similar.

Shock absorbers will make a big difference particularly if your van has none at the moment.

-- Edited by Rob Driver on Tuesday 4th of January 2022 01:25:21 PM

Possum3 · Guru

X2.

Radar · Guru

By 3 but speak with Fulcrum.

Not a fan of the other mob with thier sales talk.

Aus-Kiwi · Guru

I would say rebound would be stronger ? Just be aware of the mount strength ! Even in my 8 ton motorhome the rivets sheared off . Easy fix with fitting hi tension bolts . But can do a lot of damage if one rivet or part breaks and twists leaving holes in chassis etc . Something so easy to fix if left can creat a heap of repair !! A van would be no different ! You dont want shock limiting travel either !! It must have enough travel to hit bump stop !

Clarky 1 · Senior Member

Have to agree with the majority here. It is important to match the shock absorber to the suspension.
Just walking into a spare parts house and buying caravan shock absorbers might result in items that arent matched to do what they are meant to do.

Many caravan shock absorbers that are available off the shelf, will generally be shocks that will suit Coil Spring Suspension and these may not be suitable to leaf spring suspensions.

Professional advice will be good advice.

I had 4 shocks fitted to my leaf sprung two axle van and what a difference it made.

-- Edited by Clarky 1 on Tuesday 4th of January 2022 09:20:38 PM

Warren-Pat_01 · Guru

Thanks for your replies. And thanks Rob for the specifications - I was seeking that but have dipped out from the various web pages that I've looked at.

I partially removed one yesterday (the bottom bolt - which certainly didn't move without a fight) & tested the resistance within the unit. There is zero resistance on the upward stroke, a reasonable amount on the downward stroke. There was a "knock" when the shock was all the way up but I doubt whether the springs compressed that amount either. I would have expected a lot more if the shock was as new. I'm certain this was the same with the Eagle too in the past.

As I mentioned above Jayco & several other manufacturers use ALKO chassis equipment - at least I found the axle & bearings are rated at 3T - why they limit the wheels to 1000kg, I have no idea especially when tyres are rated up to 1300kg!! Safety perhaps? I'd like to have a look at some of the 2 wheeled camper trailers that can take more load than my van.

With that in mind I'm tempted to look at the ALCO product again but I'm not discounting seeing Fulcrum Suspension either. Like Radar, I don't go much on "The other mob." They are too ready to push their foam-cell shocks that take enormous pressure to depress & I fear would end up doing the damage that Aus-Kiwi has mentioned.

Rob Driver · Guru

Sounds like you will get on top of it Warren.

If you are confident with Fulcrum then those guys are the ones to see.

I used Pedders when in SA and they were helpful but I certainly have no affiliation.

The well meaning but little knowledge sales person that you may find in the Cheap Auto places may certainly mean well but you could easily end up with a shock absorber rated for coils. Even the Alko brand needs to be spring specific and not just a shocky to suit a caravan as that description is too general.

Good luck with it Warren, by your very basic description of the shock absorber that you tested it certainly appears that at least that one has expired.

SoloMC · Senior Member

I was in a similar situation when I picked up my van. I contacted the manufacturer who put me onto the suspension supplier. 8 new shocks, wheel alignment, brake service, bearings replaced and $1400 later, it tows like a dream and I know it won't fail when I'm in the middle of nowhere

Warren-Pat_01 · Guru

Hi again,
I have come across a really good article on shock absorbers - for touring 4wds. I guess off road caravans could be included too.
It is written by club4x4 is found here club4x4.com.au/choosing-the-right-suspension-for-your-touring-4wd-vehicle
/