Hi.
So i have about 90 kg extraweight in my x300 trunk (biogas tanks). Rear went down more than an inch now when i accidently filled the fueltank more than i wanted. I would like to have original ridehight.

Is there stiffer or longer springs available? Lowering front would be easiest but buying whole low. set feels stupid.
Wintertimes i need to keep fuel level hi to prevent moisture in tank.
lowering kits usually drop less than an inch?

Any ideas...
Br. Heikki

 

You can use plastic spacers to raise the rear of the car, there may be some in your suspension already; sometimes they are factory fitted to compensate for differing L & R heights and to bring car up to spec. height

These are placed atop the springs under the cap and there is a formula for calculating the height increase - each 1/4" of spacers raises the rear 3/8" ... so a 1/2" + 1/4" spacer each side would get you in the ballpark.

Larry

 

While adding shims at the rear you will also want to replace the foam donuts atop the springs, they squash down with age.

I believe the XJR springs are more firm, but probably the same height unladen. You may want to go with a firmer shock absorber too, i.e. Bilstein B6.

I'm not familiar with after-market springs but maybe you can get a set of shorter front springs too. There is room to work with at the front.

 

Or go for thicker KYB springs. They make two versions for X300, one standard and one thicker and the latter are absolutely fine for extra weight. I have a 70l LPG tank in the boot(full must be 100kg) and normally fill it up with other things including tools and ride height is as it suppose to be. If you still have original springs, new ones are a must. Cant find pic right now but if you place them together new KYB ones were ~2 inches taller than original ones

 

I would be inclined to put the idea of lowering your front springs out of your mind. They will already likely have sagged a little over the years, and removing the spring tension requires the correct and difficult to obtain spring compressor. The issue is at the rear, where it is much easier to work on the suspension, and where some relatively straightforward solutions exist.

 

Thanks for answers. Ill try to find those thicker springs.
Just did diff rebuild in my tiny garage and i had all parts in hand but did not realise the need. No shims in this car tough.
Hopefully springs come out without removing lower arm. I hate using spring conpessors.
Edit.seems that kyb or lesjöfors dont have heavy duty springs in catalogue anymore...☹️

 

The KYB springs you'll need are RF6742 and you can still find them, they are also in the newest KYB catalogue. You can replace them easily without dropping the rear end, no spring compressors needed, you'll just need to drop the rear frame on each side you'll be swapping spring and rear caliper and disk to get more space to get it out.

 

Quite easy once you know what you are dealing with. No compressor needed. Notice brake disc is almost touching ground with the body lifted on jacks.

Releasing the front subframe mount was all that I did (aside from + position of U-joint) to bring the arm down low enough (use hydraulic jack to relieve spring pressure).

Your springs look like the early 7-turn version like mine, which are not as strong as the later 9-turn version which I put in. Though you need even more support back there.

 

Ok thans.
just ordered new springs. hope its enough.
Heikki