The Stovebolt Site Forums The Shop Area Engine Shop Swapping 2-ton steering box to 3/4?

Hi,
New guy here needing some help. I've got a 1940 Chevy 3/4 truck with the stock suspension. I plan on rebuilding the front end and steering. I heard somewhere that the 1946 steering box was a better box than the 1940. Is that true? Next question. I've got a line on a 1946 2-ton steering box. Are the boxes compatible (ratio, fitment without modification) or is the big boy steering box just too big? Any info would be greatly appreciated. Thanks
Runningiron

Im not completely sure, but I believe the 1 1/2 ton trucks had a longer column then the 1 ton and smaller trucks. I cant vouch for differences between the '40 and '46.

If the replacement from the '46 is a GMC, then they will be different. GMC had a lot of different sizes between years and models.

Jeff

Thanks for your input. According to the seller of the 2-ton steering box, it is in pretty bad shape, so my qwest will continue for a 3/4 ton or 1/2 ton box. What's the going price for a good used 1946 Chevy 3/4 ton or 1/2 ton steering box?

Hy runningiron, the 40 steering box is a sector type, the 41 - 46 type is a recirculating ball type [less internal friction]. As far as differences between Chevrolet and G.M.C., my G.M.C. parts book lists a part number for the complete steering box assembly, while my Chevrolet parts book does not, however further research revealled that 41 - 46 Chev. and G.M.C. share the same steering shaft/ball nut assembly, so I will let you draw your own conclusions as to wheather or not they are interchangeable. I'm not sure as to the interchangeability of a 41 - 46 steering box into a 40 frame, but there may be some info on that here on the site if you do a search, hope that helps.

Another thing you run into with the bigger trucks is the steering ratios can be different.

Shop Shark,
Thanks for the info. I'm kind of in the planning stages of this build, so I'll gladly recieve any info avaiable. Thanks
Runningiron

Wrench Fetcher,
That's something else to consider with regards to adifferent ratio. I think probably the best thing for me to do is rebuild what I got and see how it steers and go from there. Thanks Runningiron

http://chevy.oldcarmanualproject.com/1929_54chevyparts/06/396.HTM

http://chevy.oldcarmanualproject.com/1929_54chevyparts/06/397.HTM

Here are the two types of steering boxes. Use these along with the manual to check for parts interchange. The Ball nut used in the recirculating ball steering box, 42-46 is the same for all commercial trucks. The housing for the 42-46 commercial is used on all except the COE. This means the 2 ton will fit your chassis OK. The column length will vary depending on the truck size, from 47 5/8" to a 49 1/4". These can be cut and shorten if needed. The ratio will be the same on gear boxes.

The 41 is the same design but uses smaller 1/4" balls, 66 of them, compared to the 42-46 which uses a 60 9/32" balls. Internals won't interchange, but the housing and bearings are the same.

Check the lower bearing races before purchase if you can. The inner bearing race is part of the worm shaft and can not be replaced if its bad. I had to shop E-bay till I found one for mine, and it wasn't cheap! Bushings, bearings, gaskets, and balls all can be bought new. The shaft, sector gear, and ball nut will have to be replaced with NOS or used if they are bad.

If you plan to use you the 42-46 steering wheel, plan on getting the whole assembly with the column. Parts of the horn mechanism are not available except used. The column uses a straight spline shaft for the steering wheel to engage on to, the 37-40 wheel uses a taper shaft with key way. The steel outer mast tube is different but will swap. The upper mast bushings are different and are matched to the horn button you plan to use. I cut the 42-46 shaft off and welded a 37 to it so I could keep my 37 wheel and horn contact.

Hope some of this helps, I just wanted to let you know the gear box swaps over, but its not a direct bolt in with out a complete unit. Having just changed mine out, I can tell you it will drive much easer. The ratio is slower so you have to turn the wheel more, but thats why they drive better.

One more thing, use a 00 or 000 grade grease in them. It takes a thin semi liquid grease to stay in the worn bearing and keep the balls lubed.

Joe

I swear I ran into a handful of different sizes when I rebuilt the box in my GMC COE. Those parts were not listed for my COE, but for different models. Maybe I was day dreaming...

If you need parts there are a few NOS suppliers listed in the links section. I got some of my replacement parts from them. And as far as price is concerned, I sold the steering column/box out of a '41 for about $50 condition unknown, but I believe it was in decent shape. Had I realized it, I would have measured its length as I have an identical unit out of a '41 1 1/2 ton truck.

Jeff

Joe,
Thanks, that info is exactly what I was hoping to find. I appreciate it.
Runningiron

Rusted Nuts,
Thanks you also for the info. The boxes and columns I think I'll be buying come with a whole bunch of extra stuff for $60.00. Providing that both the 3/4 ton and 2-ton boxes are rebuildable
Runningiron