VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 31-32 Worm Gear Spalling

What would cause the worm gear to spalling at either end of the gear?

A little more info would be helpful. How long have you owned the car? Did you know the Gear to be good back when? Temp and Lube would help also. Al W.

Since the damage is at the full lock position, i would say it could be from hitting a curb and gutter ( or similar immovable object), and having the wheel and then the pitman shaft and sector shock load against the worm gear with very little surface contact betwwen them.

Takes a H8ll of a whack to do that...if i didnt know better i'd say it was eaither droped hard at one time or for some reason, beat on.

Jack39rdstr,

Given your insightful information and considering that this old girl ('32 BA) is 79 1/2 years old, she might have been force fed a curb or three with her steering box in cranked to a vulnerable position in her younger days. I can tell you that she receives far more respect today that what you suggest the scars on the worm gear indicate she may have previously been afforded.

With new housing flange bushings, new worm thrust bearings, a less abused sector gear, and proper maintenance I am hoping that this 32 BA will track as well as she ever did.

You can see in the pictures , that the contact face is diminishing in the area where the chips are. They definately seem to be in the form of multiply chips , with the start of the force coming from the contact face with the sector gear. I would also point at that worm and sector steering gears are generally set at the tight point(high point) in the centre of the worm. If there was excessive back lash at the ends of the travel, then it may have given it more of an impact at the areas showing the damage.

Is it possible that the center is where most wear(usage) occurs and if the gears are adjusted tight at that point then the ends would have excessive contact lacking the same wear as the center??

Yes , that could be the case as well.

You fellows have not touched on another possible cause. As in if the drag link down to the drivers side wheel was off for whatever reason and someone gave the steering wheel a good spin as in some kid or ? it may do the same damage at the end of travel. This is one thing the manual tells you never to do while that drag link is off since it will damage one or the other. Essentially there are no external stops at that point. Don't know if thats what did it but it may be.

Good thought.

I may have found a suitable used sector to use in my rebuild that doesn't have excessive wear. I will be careful not to aggravate the damage to the worm gear by unwittingly turning my steering gear from lock-to-lock while the drag link is disconnected.