Instabilatiy at Speed

[J44EAG]

A good bit of research Brian.

One has to be very careful ordering online with some of these items. Many parts are Vin Number critical unless you are trying to upgrade slightly and want to put an uprated part on an older vehicle.

The listing on the Rimmmers site wjth all those different parts numbering is to my eye very similar to the British Parts listings. Again they show many and varied units for the model range.

http://www.google.co.uk/url?sa=t&rct=j& ... 2s&cad=rja

Essentially I think we need to regard the S-type as a three stage model, rather as we always have done. Each stage model improves with development. ie early models 99-2992, pre facelift mid 2002-2004 and then the true facelift and model run out cars from 2004 to 2008.

I note the reference to the 2,5>4.2 front damper. A pair of these units came up on ebay recently. They were non CATS pre face lift units and were described as being B4 Blistein. I knew they were for a prefacelift car due to there being the metal bent fork end on the lower damper mount rather than the metal ring and bush bottom mount found on early cars.(Front) So it appears Jaguar did change from Boge to Bilstein at some point. B4 and B6 units are available for all years and models across the range.

The B4 is a top range slightly stiffened unit. The B6 is a fast road heavy duty 30% uprated gas unit which to my knowledge was never fitted at the factory due to its rather specialist settings which would probably not suit the average driver. These are the units I have on my early car which are not that easy to find. Tuning houses such as Arden, Paramount etc supply and fit although the B6 units are available from sport car aftermarket suppliers such as Larkspeed from where my own units originate. No doubt id jaguar Sport (remember "Fitted at Bloxham") were still in operation, they would probably be offering them as a specialist option.

Within these parts listings we need also to remember that some of those damper listings will be for CATS and possibly ECATS equipped cars. That further fogs the issue.

Mike

[Martec]

An update on what has been found so far, very little. With the arrival of the new rear stabilizing links the other day, I spent a few happy hours underneath the back end removing the old ones, the inboard end would only slacken so far so had to be hacksawed off. The new links had copperslip applied on all threads before assembly and fitting.

Knowing that with my basic setting tools , toe in gauge and laser level and straight edge, it would take a little time to set the alignment I did that this morning. I finally got it to within the Jaguar settings range and went out for a drive this afternoon on the southbound M181 and eastbound M180. All nice and steady.......but the gale force winds of last night had gone so no real test!

I have made a few observations during the work and reading of the Jaguar 'S' type technical spec that Mike put up.

Front suspension:
The top wishbone is relatively narrow between the two inner bushes of rubber and as the ball joint can't re pressed out it is a replacement job really.
The bottom wishbone has very far apart bushes, front hydraulic and rear rubber, so this could be reused with poly bushes but would increase noise as the crossmember is not isolated.

Rear suspension:
The top wishbone has a rubber front bush and an effective 'rose' joint in the rear (my front bushes show some slight movement) but the bushes are a good 10" apart. The ball joint is not serviceable so is a replacement job again.
The bottom wishbone is the same, rubber bush at the front and 'rose' joint at the rear, but the outer 'bush' for the bottom of the 'Knuckle' feels like another 'rose' joint, so again I would probably go for a replacement rather than poly bushes.

The old 'stabilising links' at the rear were in reasonable condition except for a split rubber boot, but there is only about 5" horizontal distance between the knuckle centreline and the stabilizing link, similarly the front knuckle (swan neck upright) and the trackrod end.

So wear in the two joints of the stabilizing link over 5" is more likely to give instability over the two inboard bushes of the wishbones. this became obvious when adjusting the stabilizing links to get the correct rear toe in and thrust angle, one sixth of a turn (a flat) moved the toe in from max to min.

This time I pushed the car back and took readings and then forward for the second reading with the intention of getting both readings within tolerance. This also give a fair indication of wear and slack in the bushes, slightly more movement between the rear readings than the front readings. Thats the nice thing about having your own equipment, you can spent time trying different ideas without spending a fortune in a garage.

Waiting on a dry road and strong winds, probably not long to wait.

Brian

[J44EAG]

I no longer have these issues.

Give me B6 Billies and Adamessh springs and I have a car that works. Now I have the control and knowledge!

Mike

[J44EAG]

Sorry, Brian. Missed your post. Must have crossed with my pushing the button.

Couple of comments.

The upper front arms can indeed have new standard or Polybush/Powerflex pushed in. Powerflex replacements are blue in colour for OE spec or black if you want a harder compound. The wishbone ball joint is not replaceable. If the joint has wear then total upper wishbone replacement is needed. The same goes for upper rears. The poly aftermarket bushes in hard and soft forms are readily replaceable but at a higher cost compared to original OE parts.. New upper wishbones on ebay complete with standard bushes are available for as little as £70 each albeit copies, not OE specd originals.

The front lower wishbone can be reconditioned and tweaked. There is obviously no ball joint on early model wishbones. The front large bush though is not hydraulic. Simply an outer case tube, a great lump of Metalastic rubber compound, an inner tube and two anticompression white plastic inserts to uprate compliance as from MY2000. Remember the one I removed after it became damaged after an argument with a pothole in Birmingham? This big bush can be levered around quite a bit when on the car and in my opinion is the one bush at the front that is not quite up to holding the suspension as firmly as it could do. Very early cars may not have those white pieces of plastic inserted. The bush is large and relatively soft. That is a bush which I intend to replace with a hard black sport grade Powerflex bush in due course. The rear bush is much smaller and of different design. It is quite a hard piece of kit and I consider that it is about right even in standard form for fast road use.

Top wishbone bushes at both front and rear appear quite robust, are quite good at their job and don`t transmit vibration unduly. I`ll uprate if I consider it necessary but in the case of upper arms fronts and rear, I have no issue with those units. I attempt to be fair with my opinions and assessments which I know may occasionally ruffle feathers. In the case of those upper bushes I am more than pleased with their performance and ability to dampen noise and be fit for the purpose.

As far as rebushing upper arms if wear is found may be uneconomical. To do a rebush one has to be certain that the ball joint has a good long life ahead. Otherwise you can go to the significant costs of rebushing only to find the ball joint later worn at which point the whole arm would need replacement. Your nice new bushes would then find themselves fitted to a time ex wishbone with a clapped out ball joint.

The lower rear arm was the one which as caused so much expense over the years as the hub carrier and inner bush can wear excessively. In early days complete wishbone replacement was the only option via Jaguar Parts at £470 per unit. Racing Green and Neville stock replacement bushes at about £40 each. If you are capable of replacing a void bush or any of the other bushes found commonly in wishbones, then you can manage this one as well with the use of a universal bush remove/refit kit or with the use of a bench press. The outer bush is another great chunk of Metalastic and in service appears bullet proof. I`ve never heard of one having to be changed.

As regards the lower rear wishbone unit, some may remember the article I wrote about it in the magazine some years back. Once you have your head around that rear wishbone and the patented tube and ball, it can be overhauled with ease if you have the kit, facilities and engineering knowledge. It was built originally and referb can be done just as easily.

I too have replaced the rear track arms due to gaiter failure. £64 a pair on ebay. Now at £60 currently. I think mine came from Europarts via their internet listings. The joints on mine were sound but the gaiters shot. The inner joint has the treads depitched to make nut removal difficult. I had to use a hacksaw to get those rods off and then set the new rods to that of the originals. As you say Brian, it doesn`t take much to alter toe in and out values. Once I had finished my suspension work last year the car was taken to a specialist alignment garage to adjust where needed. If you have your own kit then that puts that additional cost to zero.

I believe the front lower bush to be the main cause of car wandering and instability. A similar bush appears to still be in use within the banana arm found on later facelift and pre face lift models. The same goes for the relocated damper bottom bushes and for the reworked drop arm type part wishbone found on those later models. That big front bush together with a large degree of negative front camber in my opinion impacts negatively on directional stability.

Due to lowered springs my early car now has a degree of positive camber induced by the lowering. That appears to stop wandering with no ill effects at all. That suits my needs fine and has been the case for nearly seven years now. Tyre wear is more even now. I used to wear of outside edges of tyres for a past time and regular tyre swap arounds were the order of the day to get maximum life from a tyre carcass. When I now tyre change, the wear pattern is even across the tread and the tyre gets changed due to being completely worn out rather than on the peripheries. I`m pleased to say my tyre wear is far less than when running a car with a standard set up.

Mike

[J44EAG]

Some detail pics here of the front lower wishbone and bush from an early model. The bush itself is similar if not the same as that fitted to the pre face lift, facelift, X350 and XF banana arms found on the later front suspensions found on those later cars.

The bush register shown here is the front one (immediately adjacent to the lower corners of the radiator on both sides of the car) in the early type lower wishbone. ID of the register is 2.702"/68.63mm.

Here are the internal parts of the bush I removed by cutting out with a hacksaw from within an ali tube outer case which is pushed into the 2.702" register above. Regret to say I no longer have the outer case available to photograph or the tube that is set within the rubber Metalastic part of the complete unit. This bush was removed due to the damage caused from my previously recounted pothole incident.

Only after three further years was the damage to the bush internals discovered and the fact that the two white internal compliance compression inserts were missing! The front of that lower wishbone had excess movement in it after the incident, caused tyre wear, slightly odd handling with a propensity for the car to wander slightly. Not good. Generally though these bushes hold up well in service. Owners rarely have issues with them. It was the pothole damage that killed this one off.

This article quite ably describes the improvements to the S-type as development work on the original chassis progressed.http://www.google.co.uk/url?sa=t&rct=j& ... GU&cad=rja

I recently drove one of the last XS 2.7D cars. I have to say I was mightily impressed. The ride had matured and the car appeared to feel much "larger". The tetchy feel around the central steering position was still there but in a rather more minor form than on any other S-type I had previously driven. My immediate thought was that the car had at long last grown of age and that those underpinnings would do well in later Jaguar models also.

Mike

Late edit. Available for all models and years are the alternative Powerflex range amongst several manufacturers. The blue range is a slightly uprated from standard bush whilst the black range will perhaps be more suited to motorsport having a harder Shore value. C&R Enterprizes and Adamesh are two such suppliers. Links for these parts and numbers are in this case solely for use on the early S-type model. MY52 > have a rather different part listing.

The front lower wishbone bush discussed above is approximately £72 a pair for blue spec. PFF27-601 and £79.20 for the harder PFF27-601BLK. Links here.
http://www.adamesh.co.uk/ekmps/shops/ad ... 2861-p.jpg
http://images.esellerpro.com/2489/I/176 ... 601BLK.jpg

And also the rear bush fitted in the front lower wishbone as PFF27-602BLK
http://www.ebay.co.uk/itm/Jaguar-S-Type ... 1125267894

[Martec]

That website you refered for a review of the S type is very interesting, I've read it several times with regard to 3 ltr and early cars. In the main it is the best I've read so far, but I have one issue with it, the reference to the manual gearbox change in 2002 from Ford to Getrag.

I have a Getrag box in my August 2000 car and from the build sheet from Marshalls of lincoln this gearbox number (Getrag) was fitted originally (or the build sheet was updated later??).

What was interesting was the reference to a change of steering rack and pump in 'late 2000', using your supplied website of 'British parts' and 'SNG barratt' catalogue it quotes a change of numbers for the pump and rack bushes at L86901/2, my car number is 3000 cars earlier. But the cross member chassis and track rod ends don't change until M45... so theoretically the pump and rack could be changed from Ford to ZF on the earlier cars. Its too cold for me to jack up and climb under to check (Ford stamped there name on everything except the gearbox). A bit more to think about inside in the cold winter, I shall be looking out for scrap front and rear LOWER wishbones in our local yards later.

Brian

[J44EAG]

There was definitely a manual gearbox change from Ford to Getrag, When I did some sub editing for Nigel for his book on the car, I picked that up as Nigel said Ford only. I don`t think Nigel ever agreed that a Getrag did find its way into the car. I let the matter drop.

The steering racks are also interesting. My MY 2000 V6 had the early type and two years on my MY 2002 had aquired the later type which was slightly better weighted and seemed rather more oily in its steering action. Worth getting a spare for replacement as I cannot seem to find any reconditioned units available or any business that can refurbish them. The situation with the pre=facelift and facelift units appears more fluid with recon units at around £350. Whether they fit an early car is doubtful bearing in mind the change of subframe layout and detail.

I`ve fitted the RG109 spherical tube replacement bushes to worn out lower rear wishbones without much difficulty using heat from a heat gun together with my bush removal replacement kit. The only thing you have to watch is that the distance between the virtually solid constructed new bushes is reset at 281mm as detailed in the big article I wrote on the subject.

Knowing as I do the design of that bush so well having sectioned one of them for examination, I note that most poly type after market producers also sell poly replacements for those special bushes. I can`t say i`m that happy about going in that direction. The original patent bushes are likely to be rather more solid than any poly type and in addition the original spherical bush is designed to handle some pivotal radial movement to allow for rear tracking adjustment. That is not possibly with a double top had and tube type poly bush which would always be under an offset side load all be it relatively small. I suspect lifespan might be limited with such fitment. With the patent bushes only costing around £40 each (two needed per lower rear wishbone) they are hardly expensive for the engineering within them. So no poly bushes in that location for me I`m afraid.

I`ve not yet removed the smaller of the two bushes in the lower front early type wishbone. I suspect it may need to be destroed in the process. I`ll see what I can achieve with that bush removal shortly. Again the distance between the two bush ends is critical. Get it wrong and the wishbone will not refit into the two mountings on the front subframe assemblies. Removal of the bush having removed its centre tube was straight forward with a little warming with a heat gun. That great chunk of rubber once removed just leaves an ali thin wall tube within the wishbone. Either the bush removal kit can then be used or a slit cut in the tube allows it to be tapped out of the wishbone register.

The interesting thing about some of these Powerflex type alternatives is that they are frequently simple top hat type bushes, one inserted each side of the wishbone with a single central tube for the bolt slid in after assembly. That is useful because that means you could rework a worn upper wishbone, either front or rear which has an all good ball joint still present. When that joint then fails, the Powerflex bushes can be salvaged and if desired easily then fitted to a new or otherwise serviceable replacement unit.

Generally these poly type replacement bushes are about half the price again compared to original units.

Another trawl on the net again this morning to find best prices for a pair of B6 Bilstein uprated rear shocks headed for the now tiring original units which struggled to carry two very rotund people this Christmas past! So two new rear dampers with postage are best priced at Larkspeed at £360 with Demon Tweaks coming in second place at £367.50.

We are learning that it is possible to adjust ride quality and rate of response anywhere between hard and soft with alternative dampers and springs. We can alter compliance to firm up where we feel it feels loose and that we can alter steering characteristics by adjusting camber angles. One has to decide on what you want to achieve and find the budget to implement changes. Any undesirable characteristics that may occur in experimentation can soon be dialed back out again by putting the car back to its original settings.

Mike

[Martec]

I can confirm that I have a Getrag box in the car on the side of the box in cast raised letters is

Getrag and then possibly stamped 221.0.0263.90 also 4610.0./01 then 226

The box number is 0012900 JAG this stamped in, and is on the build sheet, would this have been updated if a replacement box was fitted?

There was some talk from someone that ford bought out Getrag! I tried for some time to get information about this box on the internet, even emailed Getrag, but like ADAMESH..... no reply so gave up.

Brian

[J44EAG]

You might have a word with Alan Priddy at Express Gearbox in Portsmouth. Alan is an MOD retained consultant for transmission matters as well as being MD of EG. Alan has a huge insight into they whys and wherefores of gearboxes and may be able to shed some light on Getrag matters.

Most popular of ll the Getrags for Jags are the 290 unit which I`ve seen fitted to the V12 Jag units The 260 has a smaller torque handling capacity, I`m taking as stab at this but wonder if the 226 found on your box is a model number. Seems likely in view of the 260/290 type series models.

Adamesh...Geoff Adams, Jnr & Senior are pretty switched on. Very strange they never replied to you. Have to say though that all my dealings with them have been excellent , done either face to face or via the phone.

We better get this thread back on line..

Mike

[Martec]

I've moved back to this post to continue with the steering theme, last night I found this, not the definitive article I'm after but a good explanation of the Ford system and no doubt similar to the ZF:-

'STEERING DIAGNOSIS
Problems with electronic variable-assist systems include all of the same things that can go wrong with a conventional power steering system (leaks, center wear in the steering gears, pump & hose failures, etc.), plus problems with the control electronics including the vehicle speed sensor circuit, the solenoid valve and control module. Accurate diagnosis, therefore, is essential to minimize warranty returns. Most of these systems provide diagnostic fault codes that can be accessed with a voltmeter, test light or scan tool to pinpoint the nature of the fault (if the fault is electronic rather than mechanical or hydraulic).
If power to the solenoid or control valve actuator is lost, the valve keeps the bypass circuit closed so full power assist is provided under all driving conditions. The only indication of trouble, therefore, might be a loss of road feel and/or increased steering sensitivity at highway speeds.
It is important to remember that variable-rate power steering only reduces the amount of pressure that reaches the steering gear at higher road speeds. The only way it could reduce power assist at low speed would be in the unlikely event the actuator or solenoid valve failed in the open position. This could cause a noticeable reduction or loss of power assist.
If the control solenoid fails on a Ford EVO system, or the control circuit for the solenoid is lost, the valve is designed to keep the bypass circuit closed so full power assist is provided under all driving conditions. The only indication of trouble would be a loss of road feel and/or increased steering sensitivity at highway speeds. However, if the EVO solenoid valve jams in the open position, there would be little or no power assist at any speed'.

The best I've found to date, so I now need to find out what common faults Ford racks suffer from and assuming it is a closed loop control system with a pressure sensor in the line, what if any are the fault codes to look for? I can't think that Ford stuff is crap, but ZF maybe better or better suited to this heavy car?

Brian

[J44EAG]

Interesting, Brian.

I`ll have a commune with my iCarsoft unit and see if it touches steering fault codes in its library. After that it will have to be an internet search to see what we can find.

Mike

[Martec]

An update on the subject of steering racks for those interested, I've just about exhausted my internet searches (depends what questions you ask as to what the site offered are!). I have found 4 sites with exactly the same write-ups and similar write-ups on Jaguar Technical manual.

Basically at chassis number L86901 the steering rack and pump were changed and from other sources it seems that up to that number it was a ford pump and rack, but after that date they were replaced with ZF items. As the pipe connections are different these were also changed and the input shaft between the steering column unit and the rack, a lot to change but not insurmountable if you are careful to keep the steering column and rack aligned (clockwork spring contact for the airbag).

But having been under our car again (upto 6 degrees for a short time) we are L83--- and yes it is a ford rack with two wires to the solenoid WG and BG that matches the wiring diagram up to 2002, but this is where the information gets confusing so I've had to make my own assumptions.

From Ebay pictures and other sources the ford rack has a large solenoid with 5.8 ohms (approx 2 amps) American fords of that era seem to have a coil of 10-15 ohms! The ZF rack has a stepper motor and the ampage is varied to open the unloading valve over a number of steps dependant on the speed input from a sensor in the gearbox. The rack and sensor can be replaced separately, but more importantly the ampages for our Ford rack are far higher than for the ZF rack and I'm sure the Ford solenoid is either open or closed (one step down of pressure) where as the ZF has multiple steps.

The Jaguar Technical manual shows a Ford rack but the words are for a ZF rack (unless there was a later Ford steppermotor rack that I haven't seen?).

I hope that is intelligable, only cars upto later 2000 had the Ford rack and big solenoid. My next attack it to remove the connector to the 'General Electronic Control Module' ( above the front passengers feet) FH60 (black, there are 5 connectors) and test for continuity to and from the coil and check the earth connection again. I have a feeling that there isn't a fault code for this although there are fault codes P1653 and 4 that refer to malfunction of the steering system.

Also I can't confirm the speed at which the ford coil is operated, possibly 40 or 80mph (the latter lets me out then). When the snow has gone I'm hoping to see Roger again and see what racks and gearboxes he has on his early (1999) car and scrap car. I don't think it is feasable to replace the ford rack with a ZF due to the GECM.

Back now to rebuilding the MkII carbs with new jet diaphragms and then the pump and pipework.

Brian

[J44EAG]

Phew! Superb research and write up, Brian.

This is the first time i`ve come across these very valuable details. My October 2001 manufactured V8 is on M33066 which would then seem to be well in to the ZF production fitment run and explains the differences in feel between the MY 2000 V6 I ran for a while alongside my current later V8. Perhaps because the earlier car had the two stage rack system and my later the the more variable later ZF unit possibly explains why I found them so very different. In addition the brake pedal feel was also different in reaction as I believe the servo was also changed around the same period.

My recent time has been spent further researching further ways to drive down our parts costs by looking at European sites and those in the States. The Euro sites are quite straight forward and useful presently given the £-euro rates of exchange. The US sites are rather more difficult with large freight charges and taxes to be paid on import to this country. Once again I site the B6 Bilstein rear damper as the centre of my attention. UK prices delivered with VAT typically at £360 per pair all in. Euro prices delivered with taxes included at around £275 per pair all in. The Cheapest US site lists at £152 plus £64.55 post, £55 tax and £5.40 insurance. Once that lot tots up, the figure is very similar to the typical Euro prices. Not as easy as you would think for the USA. A subject well worth the investigation though.

Mike

[Martec]

Just to add a bit more to this theme whilst I remember. I've written elsewhere that I have now seen 3 'L' chassis number cars upto ours at L83--- and all have ford steering racks and Getrag 221 gearboxes.

I have borrowed Roger's spares car steering rack and reasonably accurately measured the 'Variable Ratio' of the rack either side of zero (dead ahead). In 1/4 turns of the input shaft and the rack moves:-

0 - 1/4 10mm
1/4 - 1/2 12 mm
1/2 - 3/4 14mm
3/4 - 1 14mm
1 - 1 1/4 13.3mm

Total turns lock to lock is about 2.65 ish

About 10 degrees of steering wheel movement to correct side winds is 1mm of rack movement, that must be due to suspension bush movement (tired soft bushes).

below is my 'accurate' measuring equipment!!

[J44EAG]

For reference and info, Brian, my Oct 2001 built V8 is M33066 and appears to have the ZF rack unit.

Two types of rack bushings appear to be available for the early cars. Presumably a different type for the Ford and ZF units.

Great appliance of science as regards your test equipment. Nice one.

Mike