I have read with interest the useful postings on torsion bar adjustment. My 150 FHC had the front suspension reinstalled some years ago using a shock absorber distance-piece with holes spaced at 13 1/8 and 15 5/8 inch. I do not remember which holes I used. The front end was very low with the tire buried in the wheel well. This was not helped by the rear end (with new spring) being hideously high. I waited until the engine etc. was installed before readdressing the problem.
The chassis is now blocked-up with 11 1/4 inches from ground to front cross member. Before taking the shocks and torsion bars off I wanted to check if the distance piece dimensions are correct. I seem to remember seeing somewhere that late model 150’s had a different setting. Does anyone remember this or was I dreaming?
There is no mention of torsion bars in the XK150 Supplement to the Service Manual, nor in the Service Bulletins. The 11-1/4" comes in from the XK140 Supplement, which refers back to the XK140 Owner’s Handbook.
The distance piece is described for Mark VII. Presumably you would use it for XK140/150.
XK120 uses a different distance piece because the front shocks are a different design.
On my XK150 FHC, I just adjusted the torsion bars to set the height from ground to top of wheel well at an equal distance to the rear wheels. The torsion bar is easy to adjust but you have to take the weight off the front suspension before adjusting, bit of trial and error required. If you have a very high rear suspension you will have to correct that first which means removing and re-arching the leafs.
Thanks Rob and Graham for the input. I have just found the following site which helps explain the two hole setting gauge and the XK120/40/50 Mk.7 confusion.
http://www.bobine.nl/jaguar/07-front-suspension/distance-gauge-suspension-xk-140-150/