Shock absorbers for parabolic springs

[Bigj66]

I’ve been looking for a set of shock absorbers to replace the Pro Comps that we’re originally fitted with the GB paras and from what I’ve read it seems that the shock absorber will need to be longer than standard and, be designed for use with parabolics due to the possibility of overheating from increased travel.

If that’s the case then it seems to rule out brands such as Monro, Armstrong etc and there doesn’t seem to be a massive amount of mid-price range choice out there apart from the Pro Comps which have mixed reviews so what are folk choosing when it comes to replacement?

The price of some of the top range stuff like Bilsteins is eye watering and given that I’ll not be using the vehicle with extreme suspension travel or heavily loaded, it seems difficult to justify that sort of outlay when all I’m really after is good road manners without being too harsh over bumps.

[Bowie69]

It's not really the travel that is the issue, normal leaf springs have inherent damping as the leaves slide against eachother, parabolics do not, as the leaves only have small, or no contact points if just one leaf.

So, the damper needs to work harder to control it all.

Personally, I wouldn't skimp on them. People are quite happy to shell out £300 for a set of springs because it lifts the truck and makes it look cool, but to spend the same on dampers seems lunacy to them, whereas you need both to make the truck ride and handle properly.

Top end britpart dampers seem to get better reviews on the budget side of things, otherwise you are looking at koni, king, ome etc. 

For all the effort you are putting into the rest of the truck, it seems silly to just stick pro-comps on there, especially as you say, they are often too stiff for a parabolic setup.

[Bigj66]

I didn’t know Koni did shocks for a Series...🤔

All the searches I’ve done seem to come back to Britpart or Pro Comps with ones like Spax, De Carbon etc only available for the coilers.

If anyone has specific part numbers of certain makes that could help narrow down the search it would be appreciated.

[Bowie69]

They may not list them directly, but waving a tape measure seems like something you are capable of, and in doing so you may well find one that fits...

[Bowie69]

Also, who made the springs? Asked them for recommendations?

GB springs, for example, recommend standard length shocks. If you aren't going off road I suspect you won't notice the inch or so extra travel from a longer shock.

[Chicken Drumstick]

What do you plan to use the vehicle for?

With parabolics the spring should move up and down a lot more compared to a regular leaf pack. So in theory you need a shock capable of handling this. I suspect, unless you are spending hours running high speed in the Oz outback or in Africa somewhere, it is probably way less of an issue than is often made out to be.

 

Parabolics should offer good flex, although this will depend on how many leaves they have. I found many sold in the UK are HD setups and ride badly and flex badly unless very heavily laden. I used to run 2 leaf parabolics on the back of my 88 for instance, whereas I know some sold in the UK are 4 leaf.

If you run a longer shock, you should be able to get more droop from the suspension, which is good for off road. The only trouble is, under compression it might bottom out the shock if it is too long to fully compress. In which case, you'd need to alter the upper shock mounts. Or run a shorter shock. Generally, like with the coil sprung vehicles, a +2" shock will probably work without changing the mounts though.

As for actual shocks, anything with the right mounting and length can be used. It doesn't need to be specifically sold for a Series. I used to run some Rough Country shocks, which I actually thought were pretty good considering they were pretty cheap.

If you are going firmly on road only, then extra travel doesn't matter so much. So it will be a balance between ride comfort and body control. The flexy 2 leaf parabolics will give you a lot more lean on road than a regular leaf pack. If you are on HD parabolics you may not notice this. But suitable damping may well help in this regard.

Oh, make sure you check the shock eye size. The Series is old school and uses a large eye and bush. Many modern shocks use a much smaller mounting eye.

 

Or give David at Llama4x4 a shout. I'm sure he'll be able to sort you out with something:

https://llama4x4.com/

[Gazzar]

I used Monroe gas magnums. They've done everything I've needed to do for the last ten years. Motorway, towing, twisty roads, green lanes. 

The outer is rusting a bit, but I've no reason to change them at this stage.

Cheap Parabolics front and rear, 3 leaf at back, LWB pickup.

[Arjan]

Koni for me

[Bigj66]

Thanks everyone for the feedback. Yes, for me it’s 99% road use and certainly no mud plugging.

I’ve used Monroe before and like them especially with being a gas type so if the general consensus is that for my usage, standard length will suffice then this opens up more options for me.

[FridgeFreezer]

My Bilsteins (5125 series) transformed the 109 although they're very definitely not standard fit and are towards the spendy end, around £100/corner from memory.

That and having seen the difference expensive shocks made to the racer I'm 100% convinced that good shocks are worth every penny.

[Snagger]

When my Procomps failed again on the back of my 109, I needed a quick and cheap alternative for temporary fit.  I used a pair of Armstrong MoD spec 109 dampers, and they have been great for road use with the parabolics.  Remember, they will have been specified for a 109 laden with an awful lot of kit or 8 squaddies with their webbing and rifles, and quite likely a Sankey full of heavy stuff on the hitch, to go across rough ground.  They’re certainly up to the job of a lightly laden 88 on the road, despite the spring type variation.  The only snag is that being 109 dampers, they won’t fit an 88 unless you make axle brackets to suit.  But what I’m trying to get at is that the  perception that gas dampers are essential for parabolics is wrong - none of the coil sprung models had gas dampers from the factory.
 

I didn’t need to replace the front dampers, but I’m thinking of doing the same again.  I had no problems with them at all, and they may end up being permanent if they behave well with the vehicle laden.

[Gazzar]

I think the key thing is to ensure they have internal bump stops, which most do now a days. The axle check straps were fitted for a reason.

[Bowie69]

Just now, Gazzar said:

I think the key thing is to ensure they have internal bump stops, which most do now a days. The axle check straps were fitted for a reason.

If you are running straps, then definitely standard length shocks will do it.

[Bigj66]

I’ve ordered a set of Munroe gas magnums so will give them a try during the shake down period and see how they perform.

[Snagger]

2 hours ago, Bowie69 said:

If you are running straps, then definitely standard length shocks will do it.

Fitting longer dampers without their mountings or the suspension and bump stops having been altered is a bad idea as they bottom out before the suspension, and that can cause significant damage.

[Gazzar]

2 hours ago, Bigj66 said:

I’ve ordered a set of Munroe gas magnums so will give them a try during the shake down period and see how they perform.

For your intended use, these will be fine. If you were headed to Morocco, maybe not.

[Bigj66]

2 hours ago, Gazzar said:

For your intended use, these will be fine. If you were headed to Morocco, maybe not.

I might be headed to Hull, will they cope with the M62?.....🤔

[Gazzar]

Hull, sorry, you are on your own.