Late steering box

[Nick Salmon]

I have asked several long time A7 friends if they have ever tackled the overhaul or adjustment of a late (post '36) type steering box - all have answered 'no'.

On my Opal I have a good 4 inches of rotational free play at the steering wheel. It has been getting noticeably worse of late and must be tackled. Is this likely to be something that can be dealt with by adjustment or is it most likely to be wear? Do any of our cherished suppliers overhaul such things?

All advice with be gratefully received.

[Parazine]

I have adjusted several of these hourglass boxes, including the one fitted to my Big Seven (same design as the Ruby type, slightly different components).
The bearings are ball bearings at the top and bottom of the worm and should be in good condition, with a slight preload, eliminating any endfloat on the worm.  There should be zero endfloat in the segment shaft withe the gasket fitted and the cover tightened, but no preload.
The idea is that the play betwen the worm and the segment should be constant throughout the range of travel but if the worm has worn in the centre position, this may not be achievable.
Adjust for minimum play in the centre and then check for play on the the outer parts of the range of travel. You may have to increase the central amount to avoid tight spots at the outer extremeties. Very careful adjustment is needed to get this right. Result should be smooth travel right through the range and a minimum of play at the high spots, wherever they are.

["Slack Alice" Simon]

Presumably you can grind it in, like you can the older type, if all else fails?

[Roland Alcock]

In the past I have used Steering Services http://www.steeringservices.com/
They overhauled the steering box of the Singer Le Mans that I owned at that time. 
I was pleased with their work and thought their pricing was reasonable. 

Roly

[Speedex750]

Hi,
How much better it will be depends to some extent on what's wrong with it and how far it has progressed. That said; Parazines' post above gives the three adjustments and going through them will improve it. It's important that you do the three adjustments in the order as written; column endfloat, side endfloat and mesh. I seem to think there was a long post recently about steering boxes and another (a few probably) with what to lubricate it with - have a browse? With a bit of patience you can get the lash down to a small amount with no tight spots.

Dave

[Tiger]

I have just improved the steering on my Ruby.
I found most of the play was in the linkages.
Got about 1inch play on the steering wheel now.
Lots of info on the Cornwall site
Tim J

[John W]

I rebuilt my 1938 Opal steering box a couple of years ago and as well as fitting new balls into the steering shaft I also replaced the bush in the drop arm which was worn to the extent that it was difficult to adjust the mesh and also retain lubricant in the box. I purchased an oil impregnated bronze bush from Simply Bearings which I ground a lubrication groove into with my Dremel. It made a significant improvement in being able to adjust the steering box. To finish off I filled the box with Castrol Spheerol EPL 0.

[Jeff Taylor]

Re Lubrication - Penrite Semi Fluid Steering Box Lube works well in the somewhat similar worm and peg, ball bearing & cup fitted Bishop Cam steering boxes of the 1930's MG T Type and Morris Eight.

https://www.mgbits.com/contents/en-uk/p1...500ml.html

[Mark McKibbin]

These boxes clearance wise are tight in the middle and loose at the ends so generally as the wear is in the middle all is good ...only worry about the centre, full lock will always have play.

[Parazine]

Presumably you can grind it in, like you can the older type, if all else fails?

No! There are only two teeth on the sector and they are usually worn so no grinding paste please! It will also kill the ball bearings.