Here's a super low cost way to lower the rear ride height when using KYB shocks. The XJS pictured uses stock springs, 2 Bilstein yellow shocks up front and 4 KYB shocks out back. The balance and ride is so ideal on this 6 Speed project car and I didn't want to risk not having that with GAZ adjustible coil overs. The car needed to be lower so I figured I'd try this low cost method first before throwing expensive parts at the car. The front got pan spacers and that's been covered in other threads so I'm just going to detail how to modify and extend the spring perch on a KYB shock. This will only work on KYB rear shocks.

There are few benefits to this technique.
1. Extremely low cost
2. When new shocks are needed the perch can be reused.
3. I used a 1 inch spacer, but up to 1.5 inches can be used for even a greater drop.
4. Proven technique, the Aston Martin DB7 used adjustable rear lower spring perches.
5. Wont void your shock warranty, no mods to the shock body at all. KYB's are warrantied for life. If the shock fails just send back the body.

There are a few drawbacks
1. no adjustability,,, Set and forget
2. Takes time, took me about 5 hours
3. Not a bolt on...Have to make stuff and weld or get someone to weld it for you.

Step 1. Decide on a drop height and cut a spacer.
I measured the perch distance, then loaded the car so it would sit where I liked and measured again. For me, the difference was 1 inch so I needed to fashion a 1 inch spacer. It's just that simple.


Step 2. Cut the spring perch as show in the pict below. I used a Mini lathe but a hole saw would suffice and get the job done.
Shown is the original perch on the right. On the left is the perch split with 1 inch of 2.5 inch diameter exhaust tubing. This effectively lowers the spring perch and the ride height. .


Step 3 - Weld'er up!



Step 4. - Reassemble shock


Step 5 - reinstall
She sits nice and the balance that I wanted to maintain is still there. This was fresh out of the garage but after a drive it settled a bit more. By then it was too dark for a picture.


The Result was ideal. Lower but ride and balance that I've grown to enjoy are maintained. This is a 6 speed XJS with a 6.0L V12 and the lower rear stance really helped the handling as well as rear traction from a dig.

 

I just found this. Excellent idea. I was going to machine these from 4" bar. This is much simpler. I will just get them tig welded..
I have some questions for you on this.

 

be nice to have a before and after picture of the shock/spring arraingment!
nice