7 tooth vs 2 tooth steering

[29spcoupe]

I just replaced the steering balls on my 29 Special Coupe. The steering is much better now that I don't feel the 'flat' spots when turning the steering wheel. My brother has a 31 that seems to steer in such a way that the steering wheel goes back to straight after turning a corner. My 29 doesn't do that. Is this typical of 7 tooth compared to 2 tooth steering? He also has 600x16 wheels and tires and I have 450x21 wheels and tires. Just wondering if I need to look somewhere else or not. Regards, John

[glenn in camino]

Your caster is not correct.

[Synchro909]

If you lower the ball at the back of the A frame, you increase the caster angle. Adaptors are available here but I'm not sure about in the US. They are not hard to make anyway.
Lower the ball by 5/8" equals 1 degree extra caster.
I have done this on the car in which I do long distances - makes it far more pleasant to drive.

[P.S.]

If your 2-tooth steering box is too tight (it's the adjustment on top closest to the firewall), then there will bee too much drag on the bearing, and your box will be too stiff to naturally return to center.

Castor uses the weight of the car to naturally center the steering. However, the force is minimal. Adjusting the castor by screwing up your radius ball setup is not recommended. Unless you have a bent front axle, the 1 degree you gain from monkeying with the radius ball isn't the solution. You already have several degrees of castor as Henry built it.

[29spcoupe]

I will check the steering box, thanks. Checked my caster, its at 5 degrees. I have a 7 tooth steering. Is the adjustment at the same place? Thanks, John

[Patrick L.]

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The 7 and 2 tooth boxes are different animals. The 2 tooth box has 4 adjustments which need to be made in correct order.

Caster can help with steering wheel return. Lower/less caster helps with that. Higher/more caster helps with high speed tracking. These cars are suppose to have 5º. A degree either way won't hurt anything.

That said, overall steering system condition should have more to do with proper steering than just caster.

[SAJ]

I notice the same problem as 29SPCOUPE. My early RHD 1930 roadster has a 7 tooth box and short pitman arm. Wheels off the ground, the steering is light. The balls are all new, ball sockets "easy steer" (plastic but not teflon by the look of them). The weight is on the kingpin thrust bearings, as evidenced by the fact they will not turn when weighted but will turn free when the wheels are off the ground. There is about 1-1/2 inches of backlash at the steering wheel rim.
The steering wheel has to be lugged much more than my late 31 Tudor with 2 tooth box and about 1/2 inch backlash at the steering wheel. the latter self-centres more easily than the roadster too. It is lighter, yet has a full length pitman arm and worn steering balls with steel cups. Steering in the Tudor seems altogether more "lively" than the Roadster's and I too wonder whether this is a characteristic difference of the 7 and 2 tooth boxes. Both boxes have Penrite steering lube in them, full to the top.
Both have steel wishbone balls in good condition and set at correct height with original spacers and springs. I have not measured the caster in either, but I did reset the camber in the roadster to specification (it had only 1/4 degree before I increased it). Tudor camber is about the same as the roadster. Chassis at the front of the roadster is bent about 5/8 inch to the right and whoever installed the front rubber engine mounts (non standard) did so in-line with the engine, so they are off centre on the front chassis member and the crank handle does not fit nicely in the pulley dog because of this. I will fix this some time, and wonder whether this will effect the steering feel somewhat. I guess the car crabs down the road a bit (front and back axles are out of line by about 5/8 inch), but holds a very stable line at speed.
Is the 7 tooth known to steer harder and more "dead" feeling than the 7 tooth?
SAJ in NZ