Ride leveling suspension

I have taken the car to a garage to get the rear shocks replaced. It didn’t look like it would be a fun job with just a hydraulic flor jack and jack stands. Now I have had a call from them saying the rear shocks don’t fit. The part number on the shocks is MNA3440AA. These are the self leveling ones apparently. Bummer.
So now I have two questions:

  1. How does the system work?
  2. What do I have to do to install the standard ones (I intend to use XJR ones).


The X300/X308 NEVER had the self leveling rear suspension. That system was deleted in the later XJ40 cars.

What car are you asking about?

The X350 uses AIR SPRINGS and can compensate for the ride height.

(I hate mystery cars)

I am talking about the x300. Have a look here:
The Dampers I bought do not fit and I am wondering what the difference is (appart from both the rod and the outer diameter beeing larger on the original damper).

There seems to be no hydraulic pump involed. But what confuses me is that there is no spring isolator shown in the drawing, but one was fitted. I suspect I need to change other parts as to use the XJR damper. Probably the spring and the washers?

Harald they are for the 3.2 L what engine/VIN is yours as there are about 3 or more variations. Try British Parts or David Manners to identify the part # you need as the current Jaguar Classic Parts new site is SH*T!

X308 had adaptive shocks on XJR (outside of USA)
Just saying. They Have an electric connector in the top.

The US also has ADAPTIVE DAMPENING but the OP was asking about SELF LEVELING.

Adaptive Dampening varies the damping, not the ride height.

Since the OP does not disclose his location, much of the info provided is incomplete.


I am in Germany, the car is an Italian car. 3.2l manual. VIN 777853.
I do not want the suspension that the now ruined jaguar classics website calls “ride level strut”. I would like to use the green XJR dampers. I used those on my XJ12 and was very happy with them.
The garage says they can’t fit the XJR dampers as the rod diameter is smaller than it is on the original damper. I have yet to look at it to understand why that is an issue. The spring mount has the same part number on both types of suspension, so I don’t see why the other damper wouldn’t fit.
The are no electric or hydraulic connections going to it. And the washer and nut with the correct diameter should be supplied with the new dampers.
So I am trying to find out what the differences would be. That would be helpful so I know what to look for when I go to the garage.
My main concern is that the self leveling functionality somehow adds to the spring force and the car will sit too low when I use the XJR dampers.
My assumption is I will need new springs. But will I need anything else?


Buy the SPRING-HAT for the regular dampers and mount the isolators and washers for the sport suspension dampers.

We had to do this type of conversion for the early XJ40s and Jaguar even offered a conversion kit.

You can piece together the proper components with a good used ‘spring/strut mounting’ along with the damper isolators and spring isolator.

So by spring hat you mean the spring/strut mount? Or is that another part?
The new damper came with the structure isolators, I have bought new spring isolators already.
Do I need new springs? I found kits that come with new springs.

I have been to the garage and had a look. I am pretty sure the new damper came with all the parts required to fit it. The top washer, the top and bottom insulator and the spacer tube are included.

The only concern is the springs. Do I need new ones?

And I am still unsure what the “spring hat” is and why I would need to replace it.


If your original shocks were NOT selfleveling then they should be ok to use again.

I am pretty sure what has been removed from the car were the original dampers. Part number MNA3440AA. So the car came with the ride level struts. What ever these are and how they work.
I would like to use the green XJR dampers, which are smaller in diameter and have a smaller diameter strut. They came with the spacer tube (thicker wall, same outside diameter as the original spacer tube), top and bottom washer and isolators. I have also bought new spring isolators. By the looks of it this could now all be assembled with the parts I have.
However I have two worries:
a) I don’t know how the origina ride level dampers work and don’t know if they push the car up more than the XJR ones will do. Wich would result in the car sitting too low with the XJR dampers -> I would have to buy XJR springs to avoid this.
b) Am I missing something else? Will something not quite fit and cause problems down the road? Any other parts I need to change?


Ok so we are taking about a 3.2l manual X300?
Are you sure that the shocks that came off the car are self levelling ones? As Motorcar man states the SL were discontinued on the previous model (XJ40) these were driven off the hydraulic pump situated at the front of the engine and controlled from a valve block on the right hand inner wing in the engine bay.


Yes, a 3.2l manual X300.
There are definately no hydraulics involved and also no electric connections to the dampers. But the part number MNA3440AA lead me here: https://parts.jaguarlandroverclassic.com/parts/index/part/id/C50.C5057.C5057280.C50572805870/brand/jaguar/ and I have no cloue as to what Jaguar means by “ride level”.
Here is a picture of the damper. As you can see it is a larger diameter than usual.


Harald I did the same green for black damper swap on a 3.2 X300 short heelbase - no problem, no spring swap needed. However, there is a type of damper called Nivomat that has no external pump but I think those too were only on XJ40 - not sure. Someone may have fitted Nivomats to yours and I wouldn’t be surprised if they were fatter and therefore needing different spring platforms

Be sure to use Jag washers, foams and spacer tubes and be sure to check they are correct spherical bearings at the bottom, not rubber bushes. A shop fitted Boges to one of my X300s and the rod snapped off at the first thread, due to bottom rubber bushes and flat washers and hard instead of curved washers and foam up top. Boge admitted the problem and changed the design. See threads in old J-L archive.

Peter, did your black dampers look like the one in the picture? Same large diameter?
The green dampers are OEM Bilstein, have the correct spherical bearing at the bottom and the foam and washers look good to me, too:

Googleing for Nivomat I found the exact dampers I have:

So I guess they are Nivomat dampers. So how do these work? Do they exert force in addition to the springs and do I need different springs now?

I am tempted to have just an additional spacer installed.


Harry, when I fitted Bilstein 24-018586’s to my car I also swapped springs. I used JLM12257 which have an uncompressed length of 14" (35.5cm). This is the same length as the X300 as my car is a late XJ40 with X300 suspension.

I also used one 1/4" spacer per side, bringing my rear ride height to 27" to the top of the wheel arches. BTW, ride height is governed by spring length not shock absorbers.

Bryan N figured out that a spacer increases the ride height by 150% of the thickness of a given spacer. A 1/4" spacer will give you a 3/8" rise, 2 will get you 3/4" etc.

Here’s the stance with the new shocks and springs in place.

Nivomats are a German-originated design that is self-leveling using an internal pump. If a heavy load is being carried the pump uses the reciprocating action of the shock to increase pressure internally, compensating for the extra load and “pumping” it back to the design height.

It does take a few minutes of driving to pump up the shocks to level. I first remember hearing about these on BMW motorcycles introduced in the early 80’s if I recall correctly, but they’ve been around a lot longer than that.


That’s where I came across them. You’d think it’s bound to go rock hard if it pumps up under load but it stays supple like a damper. Very useful on a bike where simply having a passenger can raise the total sprung mass by 25%.

I haven’t read the mode of action since that motorbike explanation 40 years ago but it still impresses.

The shock absorbers certainly do affect ride height by varying the spring platform height where adjustable. Mostly it’s not adjustable of course, but a different position on replacement dampers will alter things.