Recently just changed the lower control arms, front struct mounts and bearings, and anti roll ball link with bushings.
After car was jacked down, initial issue was the passenger side and driver front side suspension was much higher than driver rear side. (Roughly 4 fingers spacing)
thought the ride height sensors ain’t reading correctly and sent to another workshop who has the required software to recalibrate the height sensors.
The workshop tried and concluded issue was not the calibration, but the front suspension just ain’t leveling down.
now the gap between the wheel and fender arch is pretty even left and right but car is sitting much higher (around 4 fingers at the back and slightly more than 4 fingers at the front).
mechanic suspects there could be parts that ain’t installed correctly that cause the front not to level correctly.
Is the front suspension height adjustable electronically even though they are on springs?

 

With no car info how can we help??
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It’s a XJ351 2015 2.0L

 

Thanks!
The XJ only has adjustable suspension on the rear with the air struts? There is no way to adjust the front ride height?
Have you driven the car? Maybe a bit of road use will "settle" the suspension?

Pictures would help too.
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I’ve driven the car over 150km but doesn’t really helps. This is how the gaps look like across the 4 sides. I don’t recall the gaps are this huge, but I could be paranoid and recalled wrongly ? 😂

 

Yes the gaps look big but they are consistent looking front to rear too?
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Ride height can be checked measuring the distance from the wheel center up to the edge of the fender. The "gap" between tire and fender can vary with wheel/tire sizing so the wheel center measurement is the proper way to check it. The spec is in the manual and snippet is below. Interesting that India is higher than rest of world.

I checked my 2011 XJL with 27K miles on it. It has been in the garage for a few days so is well "settled", and tank is full. Front is 15.6" and rear is 15.8" using a simple tape measure so I think mine is typical.

It should be easy enough to check yours against the spec below.

Vehicle Ride Height
Front/Rear mm (inch) Tolerance mm (inch)
All markets except India
Front 405 (15.94) ±12 (0.5)
Rear 403 (15.86) ±12 (0.5)
India
Front 415 (16.33) ±12 (0.5)
Rear 413 (16.26) ±12 (0.5)
All wheel drive
Front 405 (15.94) ±12 (0.5)
Rear 403 (15.86) ±12 (0.5)

Ride height is measured from the centre of the wheel to the apex of the wheel arch, through the wheel centre line with all fluids at full and a full tank of fuel, no occupants/luggage.

 

An update on this issue. The suspension warning light finally came up for the first time. Brought to workshop the next day and they could not calibrate the suspension initially. And after checking they found the rear passenger side suspension leaking and replace just that part. Calibration was done but the rear passenger sit now sits slightly higher than the right side, but workshop says it’s still within specifications.
May I know for the ride higher measurement, the correct method is to measure it only after the car had been parked for several hours so that the suspension can settled in first?

 

anyone know the tolerance limit between the left and right side of the suspension ?

I supposed the +-12 tolerance limit is for the individual height?

 

Just so I am clear? You had the passenger rear air strut replaced?
Can you post what error the car had?
We don't see much trouble with the later XJ's as they just had air in the rear. So not much info on repairs?
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hi, yes just the rear passenger air strut was replaced. The Mech say as only one side was replaced, due to one side being newer part it sits slightly higher. 🤔

 

Perhaps the height sensors have been damaged or are otherwise failing? There is also one on the front passenger side lower control arm.

 

The sensors are reading correctly accordingly to the workshop though.

anyone can advise whether the proper procedure to measure the ride height is to let the car parked for awhile first while the engine is off, on the engine then do the measurement,
Or drive it for awhile first and measure it while the engine is running?

and any guideline on the tolerance limit between the left and right side?

 

Yes I found some info that maybe will help?



The manual is pretty thin on any more info. Attached are the two pages where it talks about setting the suspension ride height.
As always it leads us back to SDD. So no instructions in the manual on calibrating the air suspension as apparently it's all covered in SDD?

Here is a short description of the rear air suspension from the shop manual.





I don't know what workshop your using and I don't know what scanner/software they are using but if it's NOT SDD I think you need to get the car to someone that does have a working SDD system. What did they use to read the sensors?

Note the one strange comment about raising and lowering the the car using the air suspension switch? There is no air suspension switch that I know off unless again maybe it's a function in SDD?
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Looks pretty high, to me. When you installed the new parts, up front, did you tighten the retaining hardware with the suspension "hanging" or "loaded"?

 

...(I'm betting they tightened all of them up with the car in the air & suspension hanging free. At least the front anyway. Then the rear is just pumping-up to keep up with the front)...

 

Ah, good point, guys. That very well may be the issue.

 

yes, the workshop using the SDD for the calibration and to read the sensors.

 

The previous photos are before I replaced the passenger side rear air suspension, which accordingly to the shop could be the reason for the issue.
below latest photos are taken after I’ve parked the car overnight (after rear passenger air suspension replaced). I wanted to do the measurements but I’ve realized the rear air suspensions automatically raised up abit when I opened the car door (my measurement type was in the car).
I thought I read somewhere in the forum that the air suspension would only inflate / deflate if the engine is running?

 

May I know how is the “loaded” process like? Is it only to tighten it to specs only after the car is back on flat surface ? Does this apply only to the suspension parts? I’ve replaced both the front absorber mounts and bearings , and lower control arms.