1936 Opal Steering box adjustment.

[Chris Farris]

My Opal dates from December 31st 1936 and as such features the worm and sector arrangement rather than the more familiar worm and wheel to produce angular motion. Opportunities for adjustment are therefore fewer since there is only one position for the sector whereas the wormwheel on the earlier boxes have 3 positions and can be rotated through 120 degrees. In his A7 manual Woodrow describes how to improve the mating of worm and wormwheel by using grinding paste to abrade the high spots and produce a fit that runs freely, is free from tightness with minimum clearance.
In the section on the 1936-1939 steering boxes Woodrow makes no mention of achieving an improved fit/clearance using similar grinding paste methods with the worm and sector.  Does this imply that such an approach is a non starter?

Have any of you Ruby/Opal/Pearl owners significantly improved your steering by similar grinding methods - especially the minimising of steering wheel free movement ? Or are there other approaches to improve the steering? I'd very much welcome your comments.

[Ivor Hawkins]

There are plenty of options for adjustment on the worm and sector box, in addition to shims and I remember as a skint youth running out of adjustment on my 36 Ruby and resorting to grinding paste to try and improve things and it made things worse with accurate steering in the straight ahead position and stiffness when turning corners...I tried to rectify the problem by easing the two ends of the worm and sector with grinding paste and in the end I gave up and went down to the local scrappy and bought a new steering box and column...it cost me a whopping two quid at the time!

But in answer to your question, I think it’s perfectly possible, if the job is approached methodically, not as I approached as a spotty teenager.

[Robert Leigh]

The hour-glass steering box is designed to mesh with minimal clearance in the straight ahead position and have increasing play as you move to either extreme, to allow for wear to take place. The idea is that wear will occur mainly near the straight ahead position, but the play this causes can be adjusted out without the steering getting tight as you turn towards full lock. The important thing is to adjust to minimal play at the straight ahead position. The earlier boxes should be adjusted at full lock; If you adjust at staight ahead they go tight on lock.

[Charles Levien]

Hi Chris,

I recently noticed increased play in the steering wheel on my 1938 based special. Thought it was the steering box but after partially dismantling and checking for wear it turned out to be a quite different cause. The radius arms to ball joint connection on the cross member had loosened — when this was tightened up the play in steering was much reduced.
I guess the lesson is to look at other factors that might have a bearing on the problem like worn spring shackles, loose king pin cotters etc before assuming it’s the steering box. 
Of course if you’ve looked at all these my apologies!

Charles