I've been shaking down the XJS Shooting Brake in the last several months and thought I'd share a DIY modification I made to tighten the steering feel of my car.

The steering wheel/column are mounted by two rubber bushings. See #21 in this diagram:
Steering Column and Mounting-Upper - Parts For XJS from (V)139052 to (V)179736 | Jaguar Classic Parts UK

These get compressed over the years and on my car allowed the coned washer that sits on top to make contact with its metal counterpart below it. Originally I imagine there was a distance between them to allow the rubber bushing to isolate the steering column. On my car I could move the column up and down perceptibly which felt like a loose suspension component when driving.

Ideally, you'd replace this rubber bushing but its "no longer available." For the truly insane I bet you could find some sort of equivalent or make your own.

I decided to grind down the bottom part of the cone washer to allow some distance between it and its mate below. Here are some pics off my parts car re-creating my repair (didn't take pics first time).

This can be accomplished with only the gauge cluster removed. You can just barely reach the bottom bolts with a shirt 1/2 wrench to hold them while top nuts are turned. Make sure to disconnect the battery because the ignition switch and headlight switch will just touch your 1/2" wrench and cause a spark-ask me how I know.