Worm Gear Rebuild. Need Advice

****EDIT****
My main question at this point is... is it a normal thing to polish the chips out of the worm gear and keep using the part rather than replacing the worm gear?
They seem reeaaalllyyy hard to purchase or find availible online right now (Dec,2023).

Original message:
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Just delved into the teardown of my ross steering box, I pre-bought the sector shaft kit which has a new sector shaft and some brass bushings, and a gasket/seal.

When disassembling today, I found the spirals of the worm drive had some small areas of what look like scraped off and worn down on 2 random edges, see pics, I;m having trouble describing it.

AS YOU CAN TELL, THE SIDES OF ONE OF THE PINS ON THE SECTOR SHAFT ARE WORN DOWN SIDE TO SIDE. PROBABLY CAUSE OF THAT AREA ON THE WORM.

COULD I JUST FILE DOWN THE BURS ON THE WORM DRIVE AND BIDE SOME TIME TILL A DECENT REPLACEMENT COMES ACROSS?



Should I just throw in the towel and search for a new wormdrive? Seems like they're hard to find currently.


Anyone had any experience with ebayers from india and they're claimed "brand new" parts?

 

I have saw on here that you can knock the hardened pins out and rotate them and put them back in, they only wear in one spot. Also read that you can get new pins from John Deere Tractor parts. With rotating to an unused side of pins and dress the worm gear you can make it work better. Guys on Here know better than I do, my 66 Ross box is still good. Good Luck.

 

I agree with this. I polished a few places like this on mine. Put in a new sector shaft with mine. My pins were much worse than pictured. I am not sure mine could be rotated to a "good" spot.

 

I have a new sector shaft in a box with a rebuild kit. I’m more concerned with the worm gear.

are you guys saying I can just polish up the weird spots on the worm gear channels?
If so, that would be fantastic

 

I took my new sector and looked at where it was going to contact on the worm. It seemed it was a bit deeper than the top edge of the worm so I polished up the dinks and let it roll.

 

That worm gear looks brand new compared to mine and last time i was in there was 15 years ago. Rotate the pins and call it good! I wouldnt use a new sector shaft they are hit and miss. There was a time not long ago when they had a high failure rate

 

I rebuilt mine on the M38A1 and the with the kit I got the new bushing were too loose in the holes in the steering box. A machinist friend knurled the bushings and made them fit and rotated the pins like stated before. I assembled the new bearings, bushings, and seals. It has been good for several years now.

Dave

 

Your worm doesn’t look too bad. If you can get a quality sector shaft (and properly-fit bushings) you will be in pretty good shape.
When the worm wears badly, only a small section in the center of travel of the worm gets worn wider. You try to adjust the sector pins to fit “deeper” in the worm to take up the slack, but when you turn a little further, the pins get too tight. This is when you need to replace the worm.
-Donny

 

This all sounds like great news.
My current sector shaft was really worn on the shaft itself so I'm gonna use the newly purchased one anyway. Any tips on honing or reaming the metal bushings for the sector shaft when installing? I've never honed or reamed anything so I'm not sure what that process entails. Please be explicit if possible

 

If you replace bushings in the housing, you may get lucky and the shaft fits with no play. Check the fit of a new shaft. You might not even need to replace bushings if the old shaft had the wear.
If you have worn bushings and new bushings are too tight, you will need a reamer. This can be for the exact size, or an adjustable reamer that may have 1/16” or 1/8” of adjustment range to allow for custom fitting. Sometimes a bushing will fit the shaft perfectly (before installing), but will be too tight after its been pressed in, due to slightly compressing it when pressing into the housing. Careful reaming to size will ensure there is no excessive play of the shaft in the housing.
-Donny

 

The new bushing barely fits on the sector shaft when I test fit it. Uninstalled. I’m assuming it’ll be even tighter once pressed in.
The old bushings actually spun in place while installed in the housing so I don’t think the fit there was ideal from the PO’s rebuild.

As far as the reamer goes…do you have any links to share so I know what I’m looking for? Or would buying an exact 7/8 reamer be ok?

Also, is this something that should be done on a drill press or can I just do it by hand?

thank you in advance for the info. I’m learning as I go ha ha

 

My machinist friend installed and reamed the bushings for me. He said he had to knurl the bushings to make them fit correctly. I just assembled the steering box. He was my machinist instructor at Community College.

Dave

 

They are made that way on purpose and have to be fitted to the sector shaft after being pressed into the case. I use a brake wheel cylinder hone because I don't have a reamer that big. I chuck the hone into a variable speed drill, oil the bore with cutting oil and start honing a little at a time checking fit often until the sector will slide in.

Then I clean the housing and shaft thoroughly to remove any residual grit from the hone. I have done it this way for many years and it works fine.

I suspect Dave's machinist had to knurl the bushings because the reamer he used was a little too large. Knurling raises the surface to make a tighter fit.

 

I did my front axle bushing and brake pedal the same way, with a brake cylinder hone. plenty of oils and check it often.

 

A brake cylinder hone is a very useful tool which I have used more for stuff like this than I have for honing brake cylinders.

When my old one finally wore out a couple of years ago I bought a new set that included a brake cylinder hone, and an engine cylinder hone from NAPA for about $30, so not so expensive for tools I need to have on hand.

 

Reamers
https://www.mcmaster.com/products/reamers/high-speed-steel-round-shank-reamers-10/

 

Ok so just a 7/8 one of those on my drill press?
Or would one of these work?

for hones:
https://www.amazon.com/Brush-Resear...keywords=7/8+brake+hone&qid=1703198128&sr=8-1

https://www.amazon.com/NYXOVA-Cylin...eywords=7/8+brake+hone&qid=1703198128&sr=8-11

 

I was at my FLAPS today and grabbed a 2-stone brake cylinder hone since it was right there in front of me.

I don’t have any cutting oil, but would my Rotella 15w40 or Marvel mystery oil work? Because I have plenty of that haha

 

Regular "cutting oil" is getting hard to find.

I am getting ready to do several steering knuckle stud conversions and had used the last of the cutting oil I had cutting the swages on a set of hub / drum assemblies. One used to be able to just go to a "hardware store" for stuff like this, but sadly almost all of the family owned hardware stores are gone in this part of the country and when I walked into the place with the "helpful hardware man" (ACE) the kid who walked up asking if he could help me just got a puzzled look on his face when I asked about cutting oil. Went to Lowes, Home Depot, and several FLAPS and got the same dumb looks.

I bought a couple of bottles off of Ebay.

Marvel might work, but the swedge cutter I have cost about $100, and the counter bore bits used in doing the stud conversion on the knuckles are not cheap either, so I am careful to take care of these tools. I use oil made for the job.