Suspension Rebuild MY 2000

[oldtimer]

Hi Martec,
Have just finished having a read of the Jaguar Repair Manual you put up.
Best bit of bedtime reading I've had for ages - very revealing.

Way past my bedtime

Oldtimer

[J44EAG]

Well done indeed. As said on many occasions, the front lower foremost bushes have the most significant effect on handling and ride quality. Sounds as if you have at long last cured the wandering, Brian.

Powerflex Purple will give a huge improvement on the squadgy OE bushes. They collapse readily given age and mileage. My Black competition replacements give a very direct response and a hard edge which for most people will be just a tad OTT for comfort everyday use. Indeed Powerflex and many sellers say they are not really suitable for such use. Around town on rough roads below 40mph, one might say the ride is uncompromising for a passenger.

My secretary who is very badly physically damaged finds my car rather uncomfortable and has experienced all the changes I have done to J44 as they occurred. A slow A27 ride today to Southampton was declined this morning for that very reason. Blacks are really only for a very enthusiastic driver and might soon draw complaints from passengers unless higher speeds are maintained at which point, Blacks come into their own territory.

I`ve recently noticed a slight increase in rear suspension noise after reworking all suspension bushes. I get some slow speed squeaks from the rear ARB bushes which I replaced with Purple....the only Purple on the car, installed before I realised Blacks were available as an alternative. This scenario found on speed bumps where both wheels raise and lower together. Loads of copper grease used during assembly as also done on all other Powerflex locations. Something of an interesting curio. Perhaps temperature dependent.

Good pics of the Purple lower fronts installed. The 7mm offset takes a bit of getting used to visually. Poweflex assured me that their dimensions were exactly the same a s unused OE bushes. One has to get into ones head that the old high mileage bush collapses inwards to the centre of the bush register. That could be anything up to and beyond 3-4mm dependent on the extent of collapse. This might be confirmed prior to dismantling by measuring across the wheel aperture to see whether the wheel centre is absolutely dead centre in the wheel arch. Body alignment accuracy certainly surprised me and was confirmed by check measuring three other low mileage S-types.

Mike

[Martec]

Well it is now a week or so since the revelation in the change of handling from my hard work of rear subframe mounting replacement and the large front bushes in the front lower wishbones. The only down side (being honest) is the extra bump thump I can hear but not feel.

I did a few long journeys on motorways between the rear and then front suspension repairs and this long weekend added more to the pot of knowledge. The long weekend started with a trip across to Ikea again with just me in and the seats set up to carry a large flatpack wardrobe and cupboards. The S type swallowed the wardrobe and part of a bookcase and the Focus the rest.

Home very late and the following morning the car was now loaded with 3 front wings, a sill and some interior parts for delivery to the Marina club AGM. a 3 hour journey (or should have been) to stay with Phil (Oldtimer) for a few days before the Marina AGM.

Phil was very kind and trusting and insured his car for me to drive as a back to back comparison with our car, a 2003 3 ltr manual sport with only 45,000 miles on it. Considering we were comparing 103,000miles to 45,000, early to later suspension, early seats to sport seats and the later variable cam timing engine to the advanced or not of my engine, it was surprising.

Phil was an excellent host and very trusting and the differences in the cars were very slight. Obviously the later car had a tighter gearbox and less driveline wind up, smelt like a new car and the engine seemed less likely to stall at very low revs. But there was very little difference if any in the steering (older ford rack compared to newer and supposedly better ZF rack), almost identical handling but ours with that bit more bump/thump. The sport seats were initially uncomfortable but I relaxed into them and they became comfortable.

The overall impression was that Phil's car was the nearest I would get to a new 'S type' and it is a truely lovely car (thank Phil). Our older and higher milage car with the replacement of a few bushes and the very few poly bushes is not far behind. I do wonder if just replacing everything in new rubber would have been a better option, but the Engineer in me couldn't accept the nasty void bushes which I assume were initially to give self steer but breakdown into wibby wobbly horror.

I enjoyed two days talking to another engineer and Phil suggested my higher tyre pressures (an early attempt to solve the very loose handling) were responsible to the more obvious bump/thump (more tests at various pressure is required). I had a good look at Phils car and at the free downloaded manuals and saw that the later car had more rubber in the rear subframe mountings, almost as much as my new uprated arrangement (incidentally my MOT guy is happy with it). Also the later rear wheel arch liner is a better arrangement and time will tell if this will stop water being channelled into the sills. Due to this massively improve taughtness of our car, up to that of the later cars I have resolve to stay with standard Bilstein dampers as even the old ones are good.

A drive home via Gaydon to meet old friends in the Marina fraternity and sell the wings was accomplished with ease and comfort. It has been worth the work to find and fix this problem and has been an enjoyable journey of research and testing. I hope others can learn from my hard work and keep their older cars on the road.

Thanks again Phil for the opportunity to drive your lovely car.

Brian

[J44EAG]

You might like to try my car Brian as another comparison. Offer open if we can hook up before it gets sold on.

I always found "bump-thump" annoying. This was present on both my MY2000 V6 and on the later MY2002 V8 which were both shod with standard 16" wheels. Surprisingly this improved when I put the ex X350 19" rims, with 1J extra rim width and 245/35 tyres on. All I had then was "bump" and no "thump". I surmised that the lower profile tyres were transferring road impacts more directly to the springs and dampers and that they were perhaps working more effectively. That set up was quite good and further improved when I fitted the Adamesh spring kit. That really smoothed things out. Things got stiffer when the B6 units were subsequently fitted. Firmer certainly with less body roll but quite acceptable all round.

As regards standard OE bush material, I`m lead to believe it is around Shore 70 value. Powerflex Purple comes in at 80 with the competition Black at 95. I would have thought the Purples ideal for road use and likely to be just about right as a minor improvement upgrade which Powerflex maintain are likely to make for an improvement in general NVH control. (Noise, vibration and harshness) That all goes out the window with Blacks! Then the going does get tough!! In service I think you might find the Purple material longer lifed than standard rubber.

The front outer bush, lower rear wishbone bush type has a big effect on NVH. I believe it is similar in influence to ride quality of the 65mm lower front bush on the lower front wishbone. I found two different lower rear bushes fitted to lower rear wishbones. One was fully solid and the other had compliance air gaps which would make the ride softer. I realised how much effect those bushes had when I eventually installed a PF Black set at that point. Then harshness did markedly increase and the car really felt stiff and solid.

An interesting comparison of your cars.

Mike

[oldtimer]

Hey Up Martec,
It was a pleasure to have your company and pleased the rest of the day went well for you.

To folks around here it is just another car to clutter the place up so it was nice to show off my pride and joy to somebody that appreciated such things. Thanks for the complement

[Martec]

I have been watching the weather forecasts and with the expectation of 40+ knot/mph winds, we went out in the S type for lunch and used 3 of our local motorway/70mph dual carriageways.

All my work on the suspension has worked, I could easily hold 70 mph with very little input to keep it straight even in the gusts. Prior to this I would have been lucky to hold 60mph in these conditions.

I hadn't used the car long distance for a little while and it still surprises me how comfortable and quick it is, its just covered in shi.....muck now.

Brian