I'm Really Going To Adjust My Steering Now. Really.

[Guest imouttahere]

The other day I jacked up the front of my DB to sand and oil the wood spokes, and noticed that I've got my steering box adjusted so tight (in order to minimize lost motion at the steering wheel) that it is binding near both ends of its travel.

So while I'm working on the car, I'm going to try to pull the pitman arm off the worm wheel shaft and rotate the worm wheel 180 degrees so different teeth will be in contact with the worm at the box's center position.

I guess I'll try using various sizes of gear puller to remove the pitman arm, if it doesn't want to come off.

I shall report back on the results.

[Guest Plymouthy]

so have you considered how this is going to affect your turn radius as you alter the position in the lock to lock of the sector..

[Guest imouttahere]

I'm afraid that I really don't understand your question. I'm doing this because the service manual says you should. Therefore, I'm going to venture the opinion that maybe the worm wheel and sector are not what determine the limits of steering travel on the early DB cars.

[idrjoe_sandiego]

If you can in fact, physically rotate the gear due to absolute symmetry, (i.e., no keyways, gears cut symmetrically, etc.) it should be no problem. However you will have to determine how much of your slop is due to the worm wheel VERSUS how much is from the other possible sources of slop for instance:

1) worn worm gear

2) worn upper and lower bearings/races/thrust bushings on the steering (worm gear) shaft

3) worm wheel shaft bushing wear

4) trueness of the steering shaft itself.

Clearly, rotating the gear is only going to remove one of many potential sources of the slop. (That is, if it doesn't serve to make matters worse somehow). Have you looked at your manual and CAREFULLY gone thru the adjustment procedures step by step? They must be followed to the letter and ever so slight adjustments can make ALOT of difference. When the box is out of the car on the bench, you can really feel the subtleties.

[Guest imouttahere]

Yes, I might have a worn worm gear. I'll find out.

I've already adjusted all the slop out of the worm shaft.

I think the eccentric bushing on the worm wheel removes any slop in the worm wheel shaft, doesn't it?

[idrjoe_sandiego]

Although I haven't worked on the exact box pictured above, most worm driven boxes share many common features. Most have three adjustments and must be done in the correct order according to your manual (And not necessarily how I've listed them).

1)worm wheel shaft thrust (adjusts how much play in and out the pitman arm has). Some worm and sector boxes like the Gemmer used in the later DB's call this the sector shaft thrust adjustment.

2)worm adjusting nut as listed on your picture. Some boxes call this the steering shaft adjustment. This determines how much in and out play your steering shaft or ultimately your steering wheel has.

and finally..

3)the eccentric bushing- most boxes have some form of an eccentric bushing and this adjustment determines the critical mesh between the worm and worm wheel in your box, or the worm and the sector gear in the case of the Gemmer. This adjustment determines how much fore and aft play the pitman arm has. Ultimately this is determines how your steering wheel feels. Too tight and its hard to turn the wheel-too loose and your all over the road. If their ever was a goldilocks story, this is it. Needs to be just right.

An excellent article was written about modifications to a steering box (this one's about the Ford Model Gemmer Box), while not specifically about your box, many of the principles can be adapted to help you understand the mechanics of your box. I stole a few of his ideas plus added several of my own ideas to improve the performance and STOP THE LEAKING when I recently did a rebuild of my 1929 DA Gemmer.

http://www.abarnyard.com/workshop/steering.htm

You can buy or rent a pitman arm puller to make the removal easier. The usual PB blaster soak still applies.

Joe

[Guest imouttahere]

"...many of the principles can be adapted to help you understand the mechanics of your box."

Oh, I think I understand the mechanics of my steering box just fine. Was there something in my previous posts that indicated otherwise?

[platt-deutsch]

Thanks for the great info Joe.. I am going to try adjusting mine now..

[idrjoe_sandiego]

Sure thing P-D... let me know how it comes out. Joe

[gundog99]

Joe.. is absolutely right in his summary. I have rebuilt an early Dodge steering box; I had to have the following done:

1)The steering shaft straitened .2)The bearing surfaces top and bottom welded and reground. 3) the worm wheel shaft reground.4)all new bushes, the the eccentric bush is complicated; the shafts must all "Screw" into the bushes, other wise you are wasting your time and money 4)New upper and lower thrust bearing .0nly, after all of the above work, was I ready to change the worm wheel and the other settings.

[Guest 1930]

That is a great article Joe, thanks for posting it here, I never thought to grind the high spots of teeth to get better contact, its so obvious but I guess I get in the mindset that I cant improve the mechanics of something. Now if somebody would only come up up with the very tapered upper and lower bearings found in Joes and mine box we would be in heaven. Good job buddy!!!

[Guest imouttahere]

"I never thought to grind the high spots of teeth to get better contact, its so obvious.."

Gee, 1930, since it's so obvious, maybe you should try grinding the high spots off the ring and pinion gears in your differential and see if it makes it work better!

But seriously: yes, I have seen DBs that had virtually no lost motion at the steering wheel, but methinks perhaps those steering boxes, as well as the cars they were in, were over-restored.

How much lost motion did the early DB have in its steering wheel when new?

[gundog99]

Or they have been lucky in owning low mileage cars. The worm wheel in my car could be moved 90 degrees at a time,the wheel was marked 1 to 4; Unfortunately successive owners had rotated it, each trying to find the area of least wear!