My air suspension is 14yrs old.

 

I see comments from car owners in Canada, Europe, and down under. All seem to have better luck with all the suspension parts. The boots and bushings hold up. The air struts too.
It is not just Bilstein and Lemforder cannot do better. My A8 has Lemforder suspension and Bilstein air struts. It all is good as new. My alignment shop (Go JDog) put it on their laser alignment rack. Tech said there was no play at all in front or rear. Car was manufactured 12/2004. What ever Bilstein and Lemforder did for VW I wish they did the same for Ford. The A8 is 17 years old with original air compressor. Never rebuild either. Car can sit for a month without dropping.

 

Well, and Japan for 10 years. I think it was garaged.
I have just bought a Bagpipingandy compressor kit for stock. Humphreys Law I think.

 

Agreed. I am in Australia. Have recently bought an XJ40 which is well kept but has failed rear (hydraulic) system and will probably fit the Bilstein based conventional setup. And know about LR Discovery/Range Rover failures as I had a Discovery previously (though not with air suspension). I have a couple of other 70s Jags as well. You hear of just a few problems with the later air suspension Jags here.

But I also have an 07 VW Touareg with air suspension which I do use offroad though not that hard and mine is working perfectly, as most do. They seem to last extremely well, usually only rusting the fittings and then only in seaside areas (we don't use salt on roads here, no need!). The VWs just seem to be built to be very reliable and durable. I have had a Subaru with air too and same reliability.

 

Humidity in your area plays a big part in the life of these things, I'm sure. My car was new in Arizona, and it lived there for 8 or 9 years before being brought to Florida. When I first removed the air compressor to do the rebuild kit, water poured out of the fitting when I removed the outlet pipe. The "dryer" chamber in the compressor was literally a water tank, and the vent valve was rusted shut. Seeing that, I had zero confidence in the health of the rest of the system, and replacing the compressor, struts, valve body, maybe even the reservoir (was that a water tank, too?) would have exceeded what i paid for the car, and certainly what I could ever hope to get back for the car. Arnott coilovers and haven't looked back.

 

Not a lot of struts getting rebuilt anymore. But you are right, that particular strut is going into the local metal scrap recycler.

 

OK my car came with Strutmasters conversion already installed. I do not know when they were installed. How do tell if they have gone bad. We road around in the car last night and heard some rattles. I have purchased all the suspension parts that need to be replaced. Upper and lower control arms front and back and a few other things. It will be interesting to see how the car rides after replacing most of the suspension. I read that Strutmaster had a lifetime warranty. I looked it up last night and now it has a two year warranty. WTF I know that the Strutmasters that are on my car are the older ones probably with the lifetime warranty. I may try to exchange for new one if they let me. But again How do you know the Strutmaster have gone bad? Thanks everyone for your input. This really helps in making my decisions.

JDog

 

The debate on air suspension vs conversion comes down to a simple question: What kind of person are you and why did you buy a Jag?

To answer that there are two subsidiary questions: Why? and How Much?

Why: If one buys an X350/358 for the phenomenal ride, the classic look in an advanced chassis/body, the club-room luxury interior, then the air suspension is worth keeping. It's a Jag because Jag designs for a ride that is both supremely comfortable, yet performs well. In that case, one does not examine resale value, because one intends to keep and enjoy it. Think of it as going to Las Vegas with $5,000 that one intends to lose, but enjoy the thrill - except the pleasure lasts longer in a Jag. The only question then is how to keep it original. The OEM parts (Bilstein) are more expensive than the Rock Auto Arnott air struts, but both seem to offer similar performance. The bagpipping Andy rebuild kit costs less than a new OEM pump, but seems to do the trick for most.

How Much: If one buys the X350 because it is cheap (and they are) yet looks and feels luxurious (it does), then one has a different relationship with the car. They are old cars, not yet classics, and there is a major question on the future of classic car collectibles given (a) digital nightmares as the cars age and (b) gasoline (petrol) being priced out of the market and eventually unrealistic as a fuel. In that case, one is both watching ones budget and always looks at the car in terms of resale value. Investing in a refurbished suspension makes no economic sense. One will never get back the investment until (if) the market curves upward, so the car becomes a money pit. For these owners, ripping out the air suspension makes sense. It's not an awful ride, it's just no longer the point of a Jag.

In converting, one becomes a poser not a purist. No judgement here, both are frivolous. Indeed any sensible person will buy a boring Japanese luxury car and be done with it. Having owned one (Lexus) that I was given for free (minor fire damage I fixed in a couple of days and a few hundred in wrecking yard parts), I found the boring part sufficient to justify giving the Lexus to my cousin and going back to European.

Some people live sensible lives. They own Hondas and Toyotas. I bought an older Honda CR-V as our house guest car and don't sweat it when it comes back with the latest parking lot dent. But, for our island car with the top down, the R172 Mercedes SLK is wonderful excess. For fun on the track, our 1969 Alfa Spider. And for grand touring, nothing beats the X350. If I ever get back to international travel and drive the open roads of highland Scotland, it will be in a Jag purchased near London, used for a month and then sold cheap to a forum member who gives me a ride back to Heathrow. While I would love it to be an X350 or X150, in the autotrader.co.uk, the prices of the X-200 S-types are lower than a rental car, and having owned an x200 with the smart sports suspension, I really liked it.

Thus, the answer to the question is another question: what kind of person are you, and why did you buy a Jag?
.

• If money is the object, go conversion.
• If reliability is the object, see the previous question first.
• If money is not the object, go air, if it is go conversion.

 

Leaks are what fills the air compressor with water. If the struts are not leaking the air compressor does not run much.
I have an Audi sitting next to my XJR. It has the same Wabco air compressor. Original, never been rebuilt. It will sit for a month without dropping. Audi ordered better air struts from Bilstein than Jaguar.
If you get air struts from Bilstrin, Arnott (most like from China), or from China if they do not bleed down the air compressor can cope. If they are wheezey, it will be full of water.
Houston humidity compares to anywhere in Florida.
I think if I finally give up on the air I will try the MaxSpeedingRods coil overs. Like the adjustable preload and dampening. Features that the original struts do automatically.

 

Air being pulled in to be compressed is what fills the compressor with water. Otherwise the dryer wouldn't be between the compressor and its output port. I assume you mean that leaks make the compressor run more, which I can agree with. Who knows what the history of my car is? Regardless, there was no saving my system.

Another nice feature to have would be a vent valve on the reservoir itself, like I've had on the tank of every shop compressor I've ever owned, so you can release the compressed air and drain the water from the tank. There's no reason the systsem should be designed from the outset on the assumption that water can't get in; that's just bad design.

 

Hi Friends,

We're getting off track here. This is a thread about whether to maintain the air suspension or convert to coil springs.

It would be great if the off-topic information were posted in relevant existing threads or new threads of your own creation.

Cheers,

Don

 

Hello:
Has anyone ever converted back to air suspension after installing the conversion kit? I owned a 2004 several years ago. The air suspension worked perfectly. The ride was wonderful. Now on my new car, I noticed a lot of rattles that sound like the Strutmaster shocks are bad or going bad. How do you tell if the conversion shocks have gone bad and need replacing?

JDog

 

Just to share my experience with converting to springs. Once upon a time I swapped to full factory STR suspension from factory comfort setup of my SV8. The days when shocks were provided with signal from ASU were wonderfull. Much more control and confidence in 400hp car on the road. Not a flying jaguar anymore but you cann't sit on both chairs i prefer control and speed. Some day i was tired of ASU periodically making struts rock solid and moved to aftermarket Sachs (in front) and monroe (in rear) non controlable struts. The car lost decent amount of control and got some of jaguar nature. That was ok for some time but i noticed quite quickly that front struts do not hold front enough on high speeds and wavy roads leting car go up and down like a heavy boat. In midseason i found quite new and very cheap non controlable F-type suspension (shocks + springs) without top mounts. I could not use F-type's springs on STR top mounts thus left STR springs + f-type struts. WHAT A DIFFERENCE i tell you. The car feels like an f-type on the road very planted and capable on any speed and any curves and pace you prefer. I became 15 years younger immidiately haha)) and i can tell car added more comfort as well as now you have much less vertical acceleration on bumps and holes - goes very flat like a train. I'm very pleased with the result. Now looking for F-type top mounts to try its springs as they have progressive spring rod and step which may add more comfort on rough road and more body roll support in hard turns as STR's are straight plain springs without any tricks.

 

The only way I know of is to pull the coil overs and remove the springs. I put one end on the ground and body weight to compress.q
The dampening ability of the unit can be tested manually. After being compressed they should stroke b@ck slowly. I have seen quality shocks that could be stoked easily after 50,000 miles.
Most are also lightly pressurized. If they compress easy they are shot.

 

I have a 2004 XJ8 (X350) and air suspension is acting up again (left rear is low). It has 77k miles. Compressor was replaced last year (this is at least the second one). I am strongly considering Arnott C-2745 kit, but heard from one mechanic (who I trust) that after he has done these he recall the backs of the cars sitting higher that normal (like a 70s muscle car). He could not recall if they were XJ8 models, but were definitely Jaguars. I was wondering if anyone had any experiences like this and/or if anyone had any before and after pictures to share?

Thanks

 

Hi LagFragger,

The suspension will definitely sit a little higher right after the coil conversion, but it tends to settle down as the new springs break in and wind up not much higher than the air suspension when it was working properly.

I may have some before-and-after photos somewhere, but they tend to be an apples-to-orange comparision because X350s/X358s are usually converted because their suspensions can't maintain the correct ride height and sit down on their bump stops overnight.

I've done a lot of coil conversions and every owner has been pleased with the results. The latest generation of the Arnott kit with the Eibach springs and shocks is really quite excellent, with improved body roll control compared to earlier generations of the kit.

Cheers,

Don

 

Thanks, Don B.

If you had any 'after' pictures that would be great. I have some family nay-sayers I would like to calm.

 

Mine sat rather high at the back but settled in just a couple of miles.

This is right after setting it down. I'd done the fronts first, then the rears.


This is 30 minutes later, just taking it up the road and back.

 

Perfect! That is what I was looking for. Greatly appreciated Greatly appreciated!

 

I know it's been a while since I have posted in the forum concerning my suspension since the last replacement of Bilstein B4's, and have given a few years of good service. However, I'm now going to have to confront this issue again. I'm seriously considering a replacement pair of X351 w/DampMatic shocks for the front and building a set of rear from S Model Bilstein shocks w/DampMatic and getting a top bushing mount and a set of rear springs for the S Model. (this retains CATS but removes air suspension)

Knowing the S Model strut mounts are too small for X350, does anyone know if the X351 strut mounts are the same bolt spread as the X350?

Anyone tried this configuration? Comments?