Gear Drive Failure

tomtucson

tomtucson

New member
I have a gear drive setup that started making some clunking noises. Taking the gearbox off I found the keyways and keys were jacked-up. Looking inside the gearbox the bearings are destroyed. The whole setup seemed bulletproof so I'm wondering which caused what? I had two keys - one stayed on the driveshaft, one on the gearbox. The driveshaft is all chingered out and so is the slot in the gearbox.

Could using 2 keys instead of 1 long key be the problem?

It's a PA brand (general) model B24. The whole thing seems stout -the bearings and the gears are huge. It's got around 1200 hrs.

I'm hoping to be able to have the keyway on the driveshaft fill-welded but I'm not sure what fixes are possible.

How fast could I get that gearbox in Tucson?

Thanks
 
There are different kinds of key ways. You need to make sure that you get a hardened keyway. Sometimes people will try and sell you some raw metal stock in place of a real keyway. They just do not last nearly as long.
 
Bingo! thats the only thing that makes sense! the shaft is practically a press fit into the collar, it doesn't seem like anything could go wrong. Got the keys at Ace. THanks, thats new information to me, and I've been around a while. The mode of failure was going really bug me.
 
I just replaced my gear box, mine was so bad that i had to have a machine shop machine another slot for a key way on the other side of the shaft.

It totally destroyed the gears in the box, so i just bought a new one. This is my first and only problem i ever had with a gear box.

I think it was a combination of a bad unloader cycling on and off and bearing failure. Total cost for repair of shaft and new gear box was just under $400.00.
 
Nick

Did the machiine the new keyway with the shaft on the engine?
 
tomtucson said:
Nick

Did the machiine the new keyway with the shaft on the engine?
Click to expand...


Yes, we just removed the muffler and brought it to them. Mine was a 24 hp Honda.
 
Tom, I too have a gearbox, but only on a 13hp and I put on the beefer General Pump YGR1000P

What is the part# on the gearbox??
How much HP you running??
At what engine speed?
During the 1200hrs of operation how many oil changes??
Was the oil level always maintained?
Are you using the recommended oil?
Do you start the washer engine at full rpm?
Or gradually bring the pump up to speed??
Type of unloader?


Your answers to these questions may pinpoint the RCF (Root Cause Failure)

IF LINK DOES NOT OPEN COPY & PASTE this link in new window (file to large) it would not upload on BBS:

http://generalpump.com/PDFs/YGR1125-Reducer.pdf
 
Nigel

Because the keys are thrashed and I got them at Ace, and per Scotts post about 'hardened' keys (sounds familiar now) I am pretty certain they were the RCF. I have the 24 hp box, a trap unloader, run at about 8 gpm/3000, start the engine at speed, oil was changed and maintained. Those bearings (2) look like truck bearings, I can't imagine them going bad on their own. Nigel, the questions and the lingo make me think your an engineer of some type?

Thanks
 
Tom, somewhere in your are is a bearing store. In Phoenix it is called bearing belt and chain. Take the old bearings there and I bet that they will be able to match them up. Odds are that it is just the bearing Race that is torn up, and that is removable. The race is the part on the machine that the open part of the bearing rides on. I have not had a key way slot get ruined, though I have had multiple keyways go bad. That is how I learned about the hardened keyways.


On Edit:
Bearing-Belt & Chain Inc -
430 W 22nd St, Tucson, AZ - (520) 792-1231
 
Far from and engineer Tom, was on industrial plants five years as a mechanical tech.

I assumed the keys on your machine was from the original manufacturer. I have see keys shear and after test were done, the key stock was not as manufacturer specified.

The # one premature failure cause on the above original equipment is lubrication related, (if operated within design parameters) and some are designed with precision bearings "C3".
 
Find the bearings would be my move but the other keyway in the gear is also chingered up.

Not surprisingly in Tucson I can't find anyone with the capabilities to cut a new slot, which I know can be done from Nicks post. Half don't seem to know about hardened keys either.

I did have two shorter keys, I think that could have been trouble.
 
I am going to deem the failure due to using two keys in the keyway. At least it was a contributing factor. Ace hardware did tell me that the keys I got were hardened. So always use one key.
 
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