Ride Quality (lack of...)

[Retroanaconda]

My Series III is a short wheelbase, 1972 vintage. About 4 years ago I rebuilt it onto a new chassis, with Rocky Mountain parabolic springs (2-leaf front and rear) and the Pro-Comp 9000 (I think) shocks that came with them. Everything was obviously brand new, including the shackes/bolts etc. as well. It runs on 7.50 Michelin ZXLs which are mounted on some awful 8-spoke rims.

In the four years since I rebuilt it I will admit to the shame of only having done about 1,000 miles in the car, though this is partly due to moving to Scotland in 2012 and only just getting the 88" brought up here too as of last month. However now it's here it's taxed/MOTd again and I'd like to start making a bit more use of it (where I can afford to put petrol in it!).

My problem is that the ride is atrocious, the slightest pothole or bump smashes through the car like a minor accident and bigger potholes result in me being thrown around the cab far more than I would like. Now I am obviously not expecting it to be like my 90 but I kind of thought it would be a bit better than this!

So are there any obvious reasons why this might be the case? I've had a few thoughts/guesses but would appreciate those of people with more experience playing with leaf-sprung Land Rovers.

• Suspension not yet "settled in" due to the limited miles I've done in it?
• Car too light for spring/shock setup, or shocks/springs too heavy/stiff for the car?
• ProComp shocks don't get the best reviews, perhaps these are at fault?

I was thinking I could chuck a load of heavy stuff in the back and go for a drive - see if that improves things - or alternatively remove the shocks and go up/down the farm road (plenty of potholes) to potentially rule them out?

Finally, a gratuitous picture of the car:

[Soren Frimodt]

What angle are your shackles sitting at mate? Possibly a picture of your suspension would be nice. Yeah I've had those ProComps, not something I'd want to ever own again! Not too stiff, to the contrary, damping effect was nowhere to be found.. They, or some of them could possibly be fused together not providing any movement?

[Josh NZ]

Could it be seized shackles?

There's a thread by Landy novice a fair few pages back in this section and it outlines similar problems, I think it was called "parabolics with no real travel or comfort" or something. Might be worth having a trawl through.

HTH

Josh

[deep]

I don't know about parabolics but normal leaf springs can get some stiction if they sit around for a long time, basically very light surface rust which causes a binding which takes the suppleness away from the springs until they've hit a few bumps and rubbed themselves clean. Maybe I notice that more than most because my springs get wet frequently? Yours have been sitting for quite some time so that is a possibility, which should quickly resolve over a few miles. You can test your shocks by disconnecting one end - they should be quite heavy to move (not sticky) but you should still be able to do it by hand with a hefty push/pull. If not, that might be the problem.

However, this simply sounds like springs which are too stiff for the weight. They could be the wrong springs for your truck. I've had that before on an 88 and had the same symptoms, only resolved by putting standard springs on.

[Daan]

loosen off the shackle bolts, then drive it around for a bit and retighten might help. As mentioned the friction could be bigger due to rust. I think the parabolics have nylon slider blocks, but still worth checking.

[Retroanaconda]

Thanks guys, some food for thought there.

Being parabolic springs there should be less friction and less possibility for seizing up but it's certainly worth a look. The dampers are the more likely suspect though I think, so I'll probably start with those.

Will have a look tomorrow if the weather isn't as bad as the forecast is saying and report back.

[mickeyw]

James I found exactly the same with the parabolics I had on my 88". I actually think they were more uncomfortable than the standard springs they replaced.

With the std springs I mucked about removing the lower shorter leaves, 1 at a time. That made quite a good result, but I plumped for the paras, as the marketing machine would have you believe they were almost as good as coils for comfort. How far from the truth that was.

I would take up the point Soren is making. The curvature of my parabolics was such that it lifted the truck a good inch or two. The shackles at the front were almost the wrong side of vertical. I had trouble getting the bolts in when the truck was up on stands. I daresay perhaps the spring effect is not so good in this geometry.

[missingsid]

Hi,

7.50 tyres won't help, std swb tyre is 6.00 as the larger tyre makes them bounce front to back and the ride is choppier.

Having said that I have only ever driven my swb on 7.50's so know no different!

Marc

[Gazzar]

The ride shouldn't be that bad. I've a 2 leaf front and 3 leaf rear setup on my 109 and it's not bad at all. Not as good as a disco, but not far of the volvo estate on skinny tyres.

Mine are britpart cheapos.

I have heard the the RM are a bit harder, though, but tougher and longer lasting.

In addition to the above some thought food:

What tyre pressure are you running at?

Would you fit those poly bushes to the shocks and shackles?

Did you let the LR down from the axle stands when you tightened the shackle pins? Might be worth while running it up and down the lane with the 8 bolts loosened up and then tighten when on flat ground.

[Retroanaconda]

Thanks all. The weather is pretty atrocious today so I doubt I'll get a proper look at it, but I'll see if I can get some photos of the spring/shackle positions.

I too believed that the paras would bring a semi-decent level of comfort, and with the fact that most modern vehicles that still use leaf springs (granted not many) use parabolics I figured that they were the modern equivalent.

Hi,
7.50 tyres won't help, std swb tyre is 6.00 as the larger tyre makes them bounce front to back and the ride is choppier.
Having said that I have only ever driven my swb on 7.50's so know no different!
Marc

That is interesting, the ride is very choppy - things like speed bumps in the road are not handled well. Anything in the back gets launched by anything other than crawling over them slowly. I put the 7.50s on for the longer gearing and for better ground clearance off road.

The ride shouldn't be that bad. I've a 2 leaf front and 3 leaf rear setup on my 109 and it's not bad at all. Not as good as a disco, but not far of the volvo estate on skinny tyres.

Mine are britpart cheapos.

I have heard the the RM are a bit harder, though, but tougher and longer lasting.

In addition to the above some thought food:

What tyre pressure are you running at?

Would you fit those poly bushes to the shocks and shackles?

Did you let the LR down from the axle stands when you tightened the shackle pins? Might be worth while running it up and down the lane with the 8 bolts loosened up and then tighten when on flat ground.

Tyre pressures are about 30psi all round. When I fitted the springs I left everything loose until the bodywork etc. was all on. But it certainly wouldn't hurt to re-settle them as you suggest.

Poly bushes I've never been a great fan of, though I understand that the proper ones (Super Pro etc.) are fine and do not suffer the same issues that el cheapo ones do. Do they provide more movement then? The bushes in there are just the ones that came with the chassis and springs so no idea on make/provenance.

[Retroanaconda]

Okay the rain abated long enough to move the 88" into the workshop and I managed to get these photos of the springs/shackles at rest. Not the best I know but all I could get in a gloomy shed!

Going to go have a look at the shocks now.

[seriebil.dk]

I'm running Heystee/TIConsole 2 leaf front and 3 leaf rear on my 88" softtop, and have a Nice soft ride, speed bumps can be taken at max speed. I drive alot with heavy trailer or load in the back, machinery og building tools. Also tires are 235/85-16 or 7.50x16.

My suggestion would be these, put some load in it, take it for at long ride with lots of twists for the leafs to Deal with. Then loosen ALL your shackle bolts, like Daan suggests, rock the car alot, load it and unload it so it settles and then retighten the bolts.

By the way, how well are the bolts greased ?

Then if no good i would look at those ProComps, but by any luck they will be leaking soon, mine did, so bined those.

Use it more, use it more, use it more and they will settle better.

[Soren Frimodt]

Shackle angles don't look too bad. However I can tell you for certain from personal experience that the launching of stuff from the back on bumps you describe is down to those terrible procomps. Furthermore damping a parabolic is much harder because it has way less friction, I've tried many things when I had parabolics, and only four dampers per axle did a decent job. I've since converted back to stock leafs and will never go back, with the 11 leafed versions you can really fine-tune the ride

[Retroanaconda]

Well I disconnected the shocks, they all seem to move freely in their normal movement (though as they're gas ones they take some pushing to compress). I left the rear ones off and went for a drive up and down the lane, seemed a lot more free though obviously a bit bouncy with no damping - I had also slackened off all the shackle bolts & nuts at this point. With everything loose I am able to bounce the back of the car up and down a fair bit. Attaching the shocks again limits the movement that I can achieve quite significantly.

Tightened everything back up again now, don't think anything has moved significantly though. I will take it for a drive some time shortly (when I can afford to put some petrol in it!) and see if it has made any difference. Perhaps a trip to the Lakes to do some axle twisting green lanes would be a worthwhile exercise!

Shackle angles don't look too bad. However I can tell you for certain from personal experience that the launching of stuff from the back on bumps you describe is down to those terrible procomps. Furthermore damping a parabolic is much harder because it has way less friction, I've tried many things when I had parabolics, and only four dampers per axle did a decent job. I've since converted back to stock leafs and will never go back, with the 11 leafed versions you can really fine-tune the ride

I am slightly confused, the symptoms to me seem like the shocks are too stiff (i.e. translating too much axle movement to the chassis/body) but you are suggesting that a lack of damping can cause this effect? Or is it more complex than that?

I'm running Heystee/TIConsole 2 leaf front and 3 leaf rear on my 88" softtop, and have a Nice soft ride, speed bumps can be taken at max speed. I drive alot with heavy trailer or load in the back, machinery og building tools. Also tires are 235/85-16 or 7.50x16.

My suggestion would be these, put some load in it, take it for at long ride with lots of twists for the leafs to Deal with. Then loosen ALL your shackle bolts, like Daan suggests, rock the car alot, load it and unload it so it settles and then retighten the bolts.
By the way, how well are the bolts greased ?
Then if no good i would look at those ProComps, but by any luck they will be leaking soon, mine did, so bined those.
Use it more, use it more, use it more and they will settle better.

The bolts aren't greased I don't think, not for the purpose of letting them move anyway - I don't think the bushes are supposed to rotate around the pins are they? The movement is all within the rubber?

[Soren Frimodt]

Yeah well this is where the leafsprings has their main disadvantage, they work 'slower' than a coil spring. as there is no friction in a coil spring it can compress and stretch at an instant, leafs with their quite significant friction (also goes for para's although much less than stock) cannot absorb bumps at great speeds fast enough. This doesn't mean that it can't be under damped, you would just only notice it a bit later than with a coil spring, and not so significantly. If you've ever driven a coil spring car with no dampers at all, it'll go into this crazy kangaroo like state even on seemingly flat surfaces. A leaf sprung car will settle itself relatively quickly.

Your problem does mostly sound like too hard a spring rate though, how well does it travel? if the travel is bad its a great indicator that the springs are too stiff. But yes as suggested by yourself and others, try having a spin with extra weight, remember to also add some to the front bumper to equal it out.

[Anderzander]

I don't have much detail - but a friend fitted paras to his S3 and they were super stiff and ruined the ride. He persevered with them for a while before reverting to standard.

Unfortunately I don't remember what brand they were - but I'll ask.

[Anderzander]

Oops - I just spoke to my friend and it wasn't him :/

Though I have definitely heard of some being fitted before and them being too hard - I must have read it on a forum.

[ToyRoverlander]

What's your tire pressure set at?

[Retroanaconda]

What's your tire pressure set at?

About 30 psi or so.

If it comes to it I'll put standard springs on it I guess.

[Bowie69]

Tyre pressures down to 25, and then swap out the procomps, if you do a search across the internet they are slated as terrible for series with paras, old fashioned oil ones are much more successful

[ToyRoverlander]

Agreed on the shocks. Indeed, try lowering tire pressure as well. I couldn't find any info on how much load those tires can take at a certain pressure but you can calculate what pressure you could run.

If you know the weight of the vehicle and assume it has equal weight on all 4 corners you can calculate how much weight is on one tire. If that tire can support, let's say 3000lbs at 60psi and the weight per tire is only 1000 lbs, the pressure you could run is 60 divided by 3 = 20psi. Go for a motorway drive and if the pressure goes up by less than 10% than the pressure is correct.

That's what I've done. I run my 315/75-16 at 20psi on the road. It should actually be a bit less, more like 17 or so. Rides way better than just stuffing heaps of air in them as most do.

[Team Idris]

I had 15 psi in and it was a bit woolly, but a good ride. Realizing they were a bit on the low side I went to 25 and the ride was less amenable

20psi is probably nearer the truth?

If they are cross ply they do seem to age harden. If I leave the S1 too long you can feel the flat lumps until they 'wake up'.

[Retroanaconda]

By way of a delayed update:

Today it's nice and sunny so I thought I'd take the 88" out for a spin. Before I went out I set all the tyre pressures to 25psi and I have to say there is a marked improvement in the ride! To be fair there is also a big pile of axle/suspension components in the back which probably weight a few hundred kilos all in all (we're chucked in there as had no space when clearing out the garage) so no doubt that is helping to soften things up a bit. But the ride is now perfectly acceptable for a short wheelbase leaf-sprung Land Rover.

Not been on the motorway with it yet, if I ever do then I'll have to see how the pressures respond, but for local driving it certainly seems happier at 25psi then 30. I've got to change the wheels for standard ones soon (current 8-spokes make me sad to look at!) so will reassess it then.

[jerboa]

This is an interesting thread. I have rocky mountain paras on my 109" SW, and I was shocked to find how the ride was a stiff as it was - but I also have the pro-comp 9000 explorer shocks - which could explain it. It is however far better than standard.

I have Michelin XZL 235/85's on WOLF rims, currently at 32 PSI on each corner. I will lower them on the back of this thread and see what the effect is.

Interestingly, a good friend of mine has a set of range rover shocks on his parabolic sprung 109" truck cab. His really does ride almost like a coil sprung vehicle. I suppose range rover shocks will give you the travel you want as well..?? He did have to modify the lower spring mounts to do that though, but then he's a dab hand at that kind of thing.

I might consider the change soon, though it seems a shame to essentially bin what are relatively new pro-comp shocks to do that.

There will be people reading this in the future. I can personally vouch for the upgrade, I'd say the vehicle handles better, is safer and rides (a little bit) better. But if you get the rocky mountain stuff, beware - I had problems with the bushes. The front ones were too big (by a few thou' and the rear ones are too small (agin, by a few thou'). Consequently the front ones were a nightmare to fit (i've done a few before) and the rears are loose!!

[Snagger]

It's the dampers - ES9000s are too stiff for a lightly loaded 88" or even an empty 109. We suffer the same thing on my wife's standard and original 90XS suspension, which is more jarring than my 109. Try ES3000s.