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The only place for a coil spring is up Zebedee's arse.
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Joined: Sep 14 2016
Posts: 380

The big red beast is showing definite "Yank Tank" wallowy ride characteristics. Seems more at rear suspension related than front. I'm pretty sure that it used to be much taunter, by big 4x4 standards anyway, but its hard to evaluate the handling of your own car as one tends to adapt. Doesn't help that the roads round here are terrible for lorry humps and similar vehicle upsetting features running more or less in the direction of travel.

Normally I'd go straight to shock absorbers but new Boge labelled "OEM" units with the correct Land Rover part numbers went on about 15,000 miles ago. Unfortunately I missed putting them in service record spreadsheet so don't know exactly when. When it stops raining I'll verify that there are no leaks but they certainly looked dry on Friday.

Rear Panhard rod got new factory bushes around the same time as the shock absorbers were changed. All the front end bushes, steering assembly bearings et al have been done over the last year except for the front Panhard rod bushes which, according to the MoT man, are in fine fettle but will be done soon anyway as I have new ones. The rear ones were certainly well past their best so the front ones must be showing their age.

I've heard that dying height sensors can give wallow issues. If so what breed to go for. Britcar show genuine Land Rover factory ones at near enough £64 and £67, cheaper than Dunlop or Britpart. Island show Dunlop about £5 cheaper with OEM quality similar prices to what Britcar wants for the factory version. At Britcar prices I'm inclined to go genuine. Obviously if it is likely to be height sensors I'll change the lot. At that age if one is past its best the rest can't be that far behind. if nothing else the arms on the rear ones are looking distinctly manky.

Anything else I should be considering remembering that all the EAS stuff has been done relatively recently. Airbags, compressor rebuild, valve block re-build and so on.

Thanks

Clive.

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Joined: Dec 30 2015
Posts: 1478

The Britpart rear sensor I ordered last year turned up in the dreaded blue bag but was marked with Dunlop logos. The theory is that Britpart order enough in one go for Dunlop to be interested in a producing a batch.

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Joined: Mar 22 2016
Posts: 1112

You say you changed all bushes, does that include the radius arms ?

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Joined: Sep 14 2016
Posts: 380

Radius arm bushes. Yup thats where I started the front end re-furbishment process.

With 20-20 hindsight all the suspension refurb work I've done, except for the EAS, has been chasing this not quite right, wallowy ride feeling. Each fix made things a bit better for a while before the issue came back. So obviously I've not hit the real cause of the problem yet. What ever it is deterioration clearly continues. So far as I can see the height sensors are about all that's left. Over the last year or two it has been occasionally intermittent about sorting itself out on start up and on the low speed / high speed up and down business.

Height sensors were on the set the clock back list anyway so no worries about changing them.

Clive

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Joined: Apr 23 2019
Posts: 124

It sounds a bit weird for something essentially mechanical, like the suspension, to be inconsistent (whether bad or good). Why would the height sensors make it wallowy? Although, did you check your ride heights recently ( have they crept up, due to black spots) you may be able to take them down a couple of cm

How about tires and pressures ? Perhaps wallowy (because the panhard rod translates up/ down movement to left/ right) means you want firmer shocks ie to reduce movement in both planes? Did you take another P38 er for a spin recently to cross check? Wd be a shame to chase this only to discover "that they're all like that". I'd describe mine as more floaty than wallowy, but there's a bit of wallow in there, for sure

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Joined: Sep 14 2016
Posts: 380

Having been through everything else the EAS is about all thats left.

Now if I read certain internet references correctly the EAS is working all the time to keep the car stable when running. Obviously there is smoothing and delay but into the system so it doesn't try to be a true active ride system reacting to every twitch and bump. But it is monitoring the sensors all the time and, should things get sufficiently out of kilter, it will alter the air spring pressures to suit. Sensible, simple, system but it does rely on the sensors working linearly and tracking each other correctly. If you have sensor track damage and nonlinearities floating around the poor suspension ECU is likely to get its knickers in a twist and react wrongly. I know from work experience that fairly slow reacting systems with quite heavy damping but plenty of actuator power can do really strange things if the tracking side is off.

Anyway I've bitten the bullet. Four new Dunlop branded sensors from Island are due about 2 pm today. A metre of 30 mm delrin arrives tomorrow or Saturday to do the setting spacers and by this time next week we should be up and running with new sensors. From other occasional issues I'm pretty sure that at least one is getting up to its sell by date anyway.

Clive

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Joined: Apr 23 2019
Posts: 124

Re Delrin, a bit off topic - and I guess I'm late to the party, but if Delrin is such a pig to cut then why not use wood for the calibration blocks?

Member
Joined: Jan 16 2016
Posts: 212

I made up a set of blocks using nylon 66. It is very easy to turn and plenty strong enough.
I have also turned a set in hardwood. I think an old piece of mahogany, full of wood worm anyway.

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Joined: Apr 23 2019
Posts: 124

Tnx Dav, if my soft wood ones don't work I'll do the nylon 66, and it won't break the bank - thanks for the suggestion

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Joined: Dec 30 2015
Posts: 1478

Go the other way and get a chop saw like wot I did. Delrin? like BUTTER! :)

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Joined: Sep 14 2016
Posts: 380

Delrin is lovely stuff to machine. Sharp tool and reasonable speed with a decent cut does the deed. My fave plastic.

Don't care much for nylon. Tendency to birds nest when turning and its easy to overheat it at the tool tip getting melted bits. Especially when milling. Unfilled grades tend to move around with humidity changes too. Which is a bummer if you make some nicely fitted bearing bushes with material which hasn't been properly dried first!

Clive