U.S. DOT specifies a maximum of 2 inches of play for the steering wheel of a commercial motor vehicle. I don't know what the original play was in the 126 box, though from the nature of worm and sector steering, I suspect there was some. My 123 after 334,000 miles is getting loose but still has a bit of life left. There is an adjustment on the steering box (CCW is tighter), but after a certain point you only increase the steering effort without taking any more of the play out. Try an adjustment. If that doesn't get it to your liking, a replacement steering box will be your best option. I count six active 126s in your sig. Which one is this?

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 401,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 26,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.
99 Mazda Miata 183,xxx miles.