A friend of mine had a new rack fitted by a `Mini place' recently. Drove it about for a week. One night he turned a corner, the column spun on the pinion shaft, the car went ahead, up the gutter and demolished a fence. Nobody hurt. Could have been MUCH worse. As 9YaTaH knows...
Problem was, the pinch nut had been tightened over the years as the spline had worn, eventually there was no gap in the `split' where the bolt goes. And maybe, the new spline on the rack was smaller too. So, it didn't clamp properly.
If yours looks like this, take it off and check it. If the spline inside looks alright, recut the slit with a hacksaw, use 2 blades together for a wider cut.
If the spline is pretty much gone, go find a better column, and check there is a gap there still, after the bolt is tight..
BTW this 1/4" UNF bolt is under a lot of stress. Use a `Grade 8' one (6 lines on the head) preferably, and a Grade 8 nut. Do it up, tight- no column movement up/down at all.
NEVER use a cheapo bolt from the hardware store...

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.
