Rear springs

[ianwade007]

I own a 2.5 2003 S Type. I have a Prinz LPG conversion and a fitted towbar.The rear suspension is riding 5/8" lower than the stated measurement. Because I tow a caravan I would like to restore the correct ride height and also stiffen the suspension to reduce tail sag when towing. Are there any suggastions how this may be achieved?

[J44EAG]

Hello Ian,

The standard S-type "Comfort" suspension on earlier cars is rather boucy to say the least. I know because my car presently has that same type.

On "Sport" models the springs and dampers are rather stiffer but ride height lowered by 25mm. Perhaps not quite what you need for towing.

Chris Bruton has acces to a spring manufacturer. Might be worth a call.
01 494 875157.

I am unaware of any speciic towing spring kit redily available on the market. Obviously this is a fairly specialist field, and I wonder if one of the caravan magazines might give you a lead on suppliers of towing/heavy duty suspensions.

Hope this helps.

Mike Kennedy. JEC S-type Co-ordinator

[J44EAG]

Ian,

I`ve had a quick Goggle sesion and came up with the link below.

Google link

This company appear to have slip in spring assistors for an S-type which stop the suspension from over compressing under heavy load.

As I saw the pricing, it appears to be a humble £15.95p per set.
Part number AS 3uuu.

Worth a call to them.

Mike Kennedy

[jeff1954]

Hi Guys
What kind of a job is it to remove/replace the rear spring after the damper has been removed, and will a cheap spring compressor i.e. from eBay be sufficient.

Jeff

[J44EAG]

Detailed in my thread here, Jeff. http://www.jec.org.uk/forums/viewtopic.php?f=200&t=8040

The Silverline clamps will do the job. Grab as many coils as you can get and tighten until the spring just gets loose. At that point crack off the nut on the top of the piston. Tighten the clamps a bit more then undo the top nut. Remove all the parts and reassemble on your new dampers.

Suggest you jack the car evenly about a foot off the ground both sides and place on axle stands. Wheels off, rear radius rods disconnected, seats down, carpet moved, four nuts each side on top damper mount to be released.

Whole job will take you three to four hours.

Shout if you get stuck.

Mike

[jeff1954]

Thanks Mike for your prompt reply as always. Those 2 quid clamps on eBay have now gone, but there are other heavy duty ones with free P&P for about a tenner. They have a maximum jaw length of 380 mm/1ft 5in will that be enough.

Jeff

[J44EAG]

These would do the job, Jeff.
http://www.ebay.co.uk/itm/Pair-of-Heavy ... SwoydWlsqt

Nice little job in the cold, wind and rain in February. May on wards for me! Have two recon rear wishbones glaring at me for fitting. Weather has reduced enthusiasm so I`ll nip me super- duper-charger off for porting and polishing which I can do in the warm instead!!

Mike

[jeff1954]

Thanks Mike I will get a set of those, I won't be doing the job till the weather warms up a bit as it is only a slight knock and only does it when the weather is cold as I have said in my previous post's. The car has passed two MOT's with the Knock, but it does seem to be getting louder unless it's me because I'm listening for it every time I go over a slight bump in the road.

Jeff

PS I was looking at the spring compressors with the double claws at either end, but thinking about it maybe the radius of the claws would be greater than the radius of the spring if that makes any sense.

[J44EAG]

It does indeed make sense, Jeff. The coil diameter is not that large and the double claw jobs might be somewhat difficult to use.

Just a couple of questions. What mileage has the car. I ask because rear ARB bushes can be very worn from about 80k miles. Bonk-thonk on speed bumps etc is the typical noise. Not an easy job as the rear sub-frame has to be lowered and space is very tight. Again details are in my thread above.

Mike

[oldtimer]

Hi Ian,
Getting back to your original question about ride height. You say that your motor is sitting 5/8 inch lower at the rear end. Perhaps you could tell me what the ride height should be and where the measurements are taken from ? You mention that you also have an LPG tank in the boot. With both petrol and gas tanks full this will have an effect on ride height of course

I have an 03 S type Sport. which I tow a caravan with. The set up supports the weight of the tow hitch and the effects of bow waves from passing coaches and the like is a thing of the past. I tow both in the UK and Europe with a cruise speed of about 70mph, conditions allowing.

The Sport model certainly has a stiffer suspension set up which I am sure contributes to it's towing ability characteristics . Mike K suggests that the Sport springs lowers the suspension by some 25mm or an inch in real money. Although I have never had the need to give this aspect any thought, my instant reaction is that it is not the case based on Mk1 one eyeball. Lowered suspension really does not appeal to me so I would certainly have noticed that.

I used to tow a twin axle caravan with my Series 2 XJ12. This car is fitted with four rear coil springs at the rear. With two large petrol tanks aft of the rear axle ,a boot full of holiday junk and a caravan hooked on the back caused some back end sagging. To overcome this I installed purpose made rubber inserts into each coil spring, this improved the situation considerably. Like all things there is a down side, when the car was returned to normal daily use with perhaps only me and two 1/2 tanks of fuel it was like riding in an old truck.

As a fellow caravaner I am interested in your comments

Oldtimer

[jeff1954]

Mike The car has only covered just over 64k Last year I replaced both the rear ARB links and it seamed like the knock had gone away but the weather had warmed up. Like I said in my previous post it only knocks when the weather is cold. I'm convinced that the damper has an internal fault because the last MOT was a vigorous one as I think the tester was trying his best to find something wrong and I didn't even get an advisory.

Jeff

[J44EAG]

I suppose cold oil in a damper would be rather more viscous when cold and perhaps causes the valve in a damper to knock. One might otherwise consider the damper bushes which can "click" when worn, the top mounts can occasionally become defective, the gaiter plate on the bottom of the mount can be found with sheered fixing rivets which allow the plate to jump around, or the spring on its bottom mount could also jump out of its location.

I found it necessary to replace front dampers at 52k miles and the rear ones at around 85k. The rear ones lost their will to damp adequately, would sag with two large people in the back and one had developed a leak. I seem to recall a slight knock from the one with oil leakage. Lifting the gaiter with a screw driver would certainly confirm any leakage.

Standard dampers are cheap enough. Indeed the Bilstein B6 heavy duty/sport.uprated ones i fitted to my car last year, came to me from Rexbo.de on the internet, delivered for just £229 including delivery from Germany. A real bargain paid for in Euros.

Consider also replacement of vertical ARB links which I recall are about £32. I remember having to have a pair replaced on my first S-type only having covered 60k miles and being six years old at the time.

Nothing lasts for ever and DEW98 based cars including the X350 and XF all share the same components which do wear out in a progressive fashion. I`ve replaced ARB bushes at 44k miles and seen generally how mileage gets to these suspensions at even very low mileage. Early cars could also need new front ball joints at 30k miles which was quite alarming. Fortunately quality of that component seems to have improved over the years.

Mike