Repairing gear teeth

Bill in IL · Aug 24, 2011

Have an old gehl 120 mix mill I use 4-5 times a year to grind a couple batches of feed. Due to some bad luck managed to break a tooth off on the driven gear for the unloading auger. Replacements are no longer avaliable unless someone has an old mill laying in the weeds.

I know I have read about building up gear teeth with brazing so who has done this before and do you have any suggestions as how to go about this? Any other great ideas as how to fix this tooth?

Anonymous-0 · Aug 24, 2011

I did it once years ago on a gear that didn't carry a lot of torque. After prepping the metal I just built it up by brazing small beads across the gear one on top of the other. Once it was big enough, I shaped it with a file.

Mike M · Aug 24, 2011

You can also repair teeth by drilling and taping and screwing in bolts and then grinding them off to the right angle. Seen this on lathe back gears.

I have arc welded up teeth in JD rol-o-matic frt ends. Get some REALLY good rod made for gears. Just make sure you can get a grinder or dremal in there to shape them as this rod is not machineable.

old · Aug 24, 2011

Another option might be to buy a sprocket with the right number of teeth at a farm and home place and then weld it in place of the broken one. Done that a few times with both sprockets and pulleys

Dblair · Aug 24, 2011

back in the day we use to drill and tap the broken tooth , after grinding it away, and then put bolts in the tapped holes. then weld up the gear and either mill the gear or you can make a pattern and file the tooth back on .

Welding man · Aug 24, 2011

Depends if the gear is cast or if it is hardened steel as to how you would repair . I have made dozens of gear teeth over the years. I have put teeth on ring and pinions in tractors-swing gears on excavators- and even starter rings on old tractors,to name a few. It is a slow tedious procedure if done correctly ,but it can be done.

Bill in IL · Aug 24, 2011

I did a spark check and it is some type of steel. Orange medium length sparks and well pronounced sparks at the end. Almost like a cross between cast iron and high carbon steel but I am not great at reading sparks.

The tooth next to the one I broke has already been repaired with key stock welded to the tooth. I was thinking the same approach preheating and tig welding it on but do I just just mild steel rod? Guess I will try that first and see if it sticks. Any other suggestions?

gene bender · Aug 24, 2011

Weld it up and then do some grinding.Browing probably has the gear

armand tatro · Aug 24, 2011

Have you considered replacing the gears with a common hyd. motor either direct-drive or set the motor beside the augor and drive with a chain? I think some grinder-mixers came with this drive setup instead of gears, The hyd. motors from fertlizer augors for gravity boxes don"t take a lot of space for mounting. Let us know how you fix or repair this problem. Armand

Welding man · Aug 25, 2011

It could be mallable iron or heat treated cast iron. Both are fairly easy to grind. If it is either of those I would use a couple of passes of nickle arc cast rod to bond to the cast and build up the tooth with 7018. If it is heat treated high carbon steel it will be hard to grind and I would use some type of tool steel rod such as Super Missleweld. Once they have cooled you can form the teeth with a die grinder and assorted rotary files. Make a template out of sheet metal to match a couple of the good teeth and grind the teeth to match the template. Not rocket science, just take a lot of time and patience.

Repairing gear teeth

Bill in IL

Well-known Member

Anonymous-0

Well-known Member

Mike M

Well-known Member

old

Well-known Member

Dblair

Well-known Member

Welding man

Well-known Member

Bill in IL

Well-known Member

gene bender

Well-known Member

armand tatro

Well-known Member

Welding man

Well-known Member

Similar threads