VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 '51 Steering Column/worm gear

We have determined that the worm gear has come loose on the steering shaft splines on a '51 passenger car. Without further disassembly we can't determine how the worm gear is pinned or pressed on the shaft. Can this be repaired with the box in the car or does the entire assembly need to be removed?

Coach

Part II...
Curiousity got the better of us so we removed the steering column assembly and took it all apart. The worm gear has indeed come loose from the shaft. It does not appear to be pinned or connected other than to be pressed on the steering column with a keyway. It may have been shrink fit but the results are the same.
Looks like the only fix is to tack weld the shaft to the gear unless anyone else has an idea about how to secure the gear to the shaft.

Coach

Coach; Although I have never had to make a repair as you have described I have run into similar problems with diff applications. I personally would knurl the end and press fit in and then I would drill two holes 180 degrees from each other at a 45 where the shaft fits in the sleeve. I then would weld it and file flush. Just a thought.

Aero:
Thanks for the input. We need to be very careful about drilling and welding as both ends of the worm gear are the races for the bearings. A buggered up weld will not sit well (pun intended) with the bearing!
We had considered drilling through the worm gear to pin it to the shaft, but we believe the gear is probably hardened steel and the pin could interfere with the gears.
So, we're probably going to pursue welding the open end of the worm gear to the shaft.

Part of the reason for posting these messages was to see if anyone else has experienced this issue. It all started when the owner noticed the horn didn't work. There wasn't enough travel left in the adjusting screw to compensate. Next, the turn signal cancelling device jammed up and wouldn't cancel. By attempting repairs on both he leasned on the steering wheel and the wheel dropped 1/2" to 3/4" and that led us to discovering the worm gear was loose. I wonder how many of the "My ('49 to '52) horn stopped working" messages MAY have been due to a similar problem.

Another thing that you might look at would be to knurl the shaft and then install the worm gear with red Loctite on the shaft and in the keyway. This might work if you don't have an excessive amount of wear.

:) :grin:

I would suggest welding as a last resort. Knurling or shimming would be my first suggestion if the shaft and gear are not worn out of round. It is critical to have the worm gear centered on the shaft and welding can easily draw the gear to one side of the gap and can effect the toughness of the metal. Filling the gap evenly around the shaft so you have a few thousanths interference fit is the best. A couple of drops of the red stuff (as recommended by the dog) will hold it forever.

I am sure the gear is hardened so drilling is likely a difficult task at best. Then there is the problem of grinding the pin level without effecting the gear.

If you don't have the necessary tools a good machine shop should be able to put it back together correctly. Often a retired machinist has the necessary expertise and tools and would rather be helping someone versus staring at the idiot box (TV). The trick is to find them.

Junkyard dog & Chipper got it right!!! NO WELDING.. If you cant knurl the shaft yourself have a machine shop do it. If you can do it your self, then only knurl lightly about .003 to.004 inch. then new key ? put the shaft in the freezer for a day. so now you are about ready to put it back together. almost one hr before assemble put the gear on a hot plate on high for 45 min to a 1 hr. get ready you want to work quick. out of freezer to vice with soft jaws, locte on shaft, key in, gloves so yoy dont burn yourself, & channel lock pliers, to pick up hot gear, put it on. you most likely will need hyd. press to finish the reinstallation let it cool a hr or two. good luck

Thanks to all for the advice. As it currently stands the worm gear is loose enough to slide on the shaft with a little tapping, but not so loose that we could shim it without turning the shaft down. Maybe the Loctite red is the answer. I was also offered a replacement shaft so I will discuss this with the owner.
I suppose the knurling and shrink fitting would be a reasonable substitute. I don't think welding is out of the question provided we pre-heat and quench properly. Distortion at the end of the shaft, if any, would be minor. We're only talking about a couple of tack welds to secure the worm to the shaft.
We'll get back on this early next week and keep everyone advised. Thanks again.

Coach

We were able to spend a little time on the repair yesterday and we secured the worm gear to the shaft. The gear was slid down about an inch and a half from the original location and we made numerous punch marks on the shaft. We then drove the worm gear back to its original location and measured carefully. The final fit was made with light taps on the gear. We further secured it in place with a few tack welds at the bottom open end of the gear. Leaving nothing to chance, some Loctite red was run down the keyway and around the top of the worm gear at the shaft after the weld had cooled. Hey, you only want to do this repair once!
We'll reassemble it all tomorrow and get her back on the road.

Thanks to all for the suggestions!

Coach

You might advise the owner/driver not to have such a strong death grip on the steering wheel on long trips. :)

You're right! I think it all started with that 'whoopie cushion' he sits on to see over the steering wheel. And ever since he got those radials she can corner like a Ferrari so he has to hang on to the wheel to handle the G-forces. That poor gear didn't stand a chance!

Coach

Just reading this post I had exactly the same problem with my 53 earlier this year. Each time I drove the car for about 30 minutes or a little longer the steering wheel would slowly rise up. I then had to push it back down. In actual fact the shaft was coming up from the worm. The steering column was removed from the car (not a very fun job), and yes the worm had disconnected. The shaft was sent to a steering shop where they apparently heated it, then tapped the worm back on and I guess when it cooled down it kindof was like a press fit again in its original location. We then put a steering box kit through it and changed the seal, a once only job. Painting the column from all the scratches with a spray can when re-installing was also not a fun job, but it was acceptable finish. Now my steering has no freeplay, and no risk of loosing steering on a freeway.

Good deal, Tony! We realized that with the worm gear captured in the box and remaining engaged with the sector gear there really isn't a way to 'lose' steering as long as the steering shaft doesn't rise up too far. Still, it's rather unnerving to think of such a key component loose on it's mourings!

Coach

Coach/Tony, You shold send in a little warning/story for the G&D telling of the problem. I have never heard of it before but undoubtly is happening.
Let me know because if you do not wish to do it I will.

Sounds like a plan Gene. I'll speak with the owner and we'll let you know if we can draft something up. If he's agreeable we will contact Tony and include his experience as well. Perhaps we can draft this and have you submit it to G&D as one of the Technical updates?

Sounds good to me. Should help to solve the mystery for others with this problem.

I am sure glad that others are having the same problem with the steering mask. I have asked for years about this and no one has been able to help me.Thanks for the solution. The story in Jan/08 G&D is alittle confusing as they tryed to write it as a tech order..

The actual post is below

Sounds good to me. Should help to solve the mystery for others with this problem.