# Gilson 55012 gear drive-bent impeller shaft,cracked gearbox,worn keyways



## greatwhitebuffalo (Feb 11, 2014)

well today I found time to get the Gilson 55012 gear box apart. One auger tine was seized on the auger axle shaft. I took it down to the local machine shop to have it pressed off. The bronze gear was seized onto the auger shaft and was VERY difficult to remove. We had to remove the entire axle shaft with seized auger tine still on it, from the other side. Once we got the bare axle with just the auger tine on it, we were able to then press the tine off the axle. It was rusted on there solid, and even though I heated it repeatedly with the torch, I could not drive it free with a sledge hammer and brass drift. We had to put 8 tons of press on it for it to come free. The press only does 15 tons max at the shop. Talk about seized on. 

the impeller/worm shaft pressed easily off the impeller. I had it almost all the way off driving it off with a hammer and drift, then it stuck inside the impeller. The press took it right off.

YES, impeller/worm shaft is BENT. Visibly so, see pictures below before we pressed it off. The impeller is also very bent. Just a word of advice to anyone buying one of these vintage machines. I only paid $75 for this one. Good thing. If you are buying a restored or repaired machine, be sure to run it first to make sure all this stuff is not bent. More to follow as the auger shaft keyways, gear, and gear box were also beat up.


----------



## greatwhitebuffalo (Feb 11, 2014)

*bronze gear*

the sacrificial bronze gear has a crooked keyway and hairline cracks forming in the lower corners of the keyway


----------



## greatwhitebuffalo (Feb 11, 2014)

close ups of gear keyway


----------



## greatwhitebuffalo (Feb 11, 2014)

the left side auger tine was seized solid onto the auger shaft. here's what it looked like after having the tine pressed off


----------



## greatwhitebuffalo (Feb 11, 2014)

now the keyway on the auger shaft. there appears to be a bulging section of the axle on one side of the keyway, and the wall of that side is also at an angle, not parallel to the other side. I've never seen a good keyway look like this, either it was machined crooked to begin with, or wore like this from hitting obstacles with the machine while snowblowing over time. The key wobbles around in the keyway. The gear does not slide easily over the area where the keyway is, even when the key is removed, because of the bulging area along the one side of the keyway. You can visibly see the raised material there with the naked eye. Also the front end of the keyway is smeared over the snap ring groove that holds the gear in place when assembled.


----------



## greatwhitebuffalo (Feb 11, 2014)

here it is with the key dropped in, the woodruff key just flops around in the keyway...not good. The gear was tight on the shaft, held in place by the raised material on the one side of the keyway, perhaps it was designed this way, but it sure is not the optimum setup IMHO.


----------



## greatwhitebuffalo (Feb 11, 2014)

here are some closeups of the raised area of the shaft, along the one side of the keyway for bronze gear. Oddly enoughly this does not go along with the direction of rotation and where the load would be placed on the keyway, it's on the minor thrust side of the keyway. Perhaps this bulge was machined in to lock the gear to help prevent it from turning, in case the keyway and key began to fail ? I don't know for sure, but that is the effect this lump of material has. I cannot simply slip the gear over the keyway slot, even with the key removed, the gear gets hung up on the bulge of material next to the keyway.


----------



## greatwhitebuffalo (Feb 11, 2014)

*cracked auger box housing tube*

now the bad part. the cast in portion of the seal retaining boss, was broken away and fell off in a little ring of cast iron. That in itself is not a deal breaker, as I can have it welded up and re-machined to size easily. 

but taking a close look inside the auger gear box axle tube, there are hairline cracks inside the tube in the i.d. in 2 places. They spread from the oil groove area that is machined into the i.d. of the axle tube.

and this machine was still running. amazing. I could repair the box and make it run again. but I found a complete auger gear box, impeller/worm shaft, and auger shaft, still assembled minus tines and pulley, for $85. It's on the way in so will go with that, or mix/match the 2 assemblies to get one good running assembly.

here's the cracked housing


----------



## greatwhitebuffalo (Feb 11, 2014)

suffice to say, the evidence shows, this machine went through a war !! 

but we'll get 'er goin' again...

actually I could have blown snow with it as is, if I was willing to put up with the vibration


----------



## greatwhitebuffalo (Feb 11, 2014)

just an FYI, on a lark I asked the machine shop owner if he would spin off a hardened, high quality material IMPELLER SHAFT for the Gilson, using the original as a pattern. He would make up a new one of much higher grade material, that would not bend under any circumstances in the machine, for around $125. 

I am seriously considering that option. Just thought I'd pass that on to the forum. changing out the shafts to one of higher quality metallurgy means this would not happen again if the machine ingested a rock or obstacle, the shaft would not bend.


----------



## RedOctobyr (Mar 2, 2014)

Wow, very interesting thread! Thanks for posting all the details. Sorry it's had a rough life, but it sounds like you're still making progress. 

I have a very *tight* keyway on my Ariens that's in-process. I had to weld onto the Woodruff key to get the old one out. A new key would not go into the groove. So I've belt-sanded the side of the new key, to allow it to slip into the groove. 

I fear I made have taken a bit too much off the key, now it's just slightly loose in the groove. I can get another key and take a little less off, if that would help avoid trouble down the road, by keeping a closer fit in the groove. 

I had trouble getting the pulley off the hub, at the end of the impeller shaft. I had to hit the pulley with a mallet to try and pop it off the hub, which still didn't work. I'm hoping I didn't bend the end of the shaft in the process.


----------



## greatwhitebuffalo (Feb 11, 2014)

get a new key, file it so you have to tap it into place, a snug fit. Not a good idea for keys to be rattling around in the keyways. A key is cheap enough, and it would be easy to fix correctly now, difficult to fix correctly later.


----------



## RedOctobyr (Mar 2, 2014)

After I posted that yesterday, I started thinking along the same lines. 

So today I had already bought a new key, and used a flat file to gradually make it thinner, until it would just slip into the groove  Great minds... 

I didn't make it tight enough to require tapping it in, unfortunately. Maybe I should have. But it's a nice fit, I removed just enough so it would slip into the shaft. There's no appreciable play this time. I also coated everything with anti-seize, to try and make things easier to remove again in the future.


----------



## greatwhitebuffalo (Feb 11, 2014)

it's only a snowblower, not a 500 horsepower machine or car engine, that should hold it. this one was running with what appears to be a loose keyway. once the torque hits the augers and they take resistance from the snow, everything will take a set and be stuck in place.


----------



## greatwhitebuffalo (Feb 11, 2014)

hope everyone had a good spring and summer. My spring was wicked, very busy and lots of challenging issues. It's getting harder to live in the USA lately. did you notice ? believe it or not, we had some a-hole new code enforcement jerk going around hassling people about leaving their tractors and snowblowers in their driveways in view from the street. He's also got his panties in a knot over old cars sitting with covers on them - WTH is this guy a communist or what ? well he's going to be straightened out pronto. can you believe this crap ? like they don't have something better to do. code enforcement sucks, it's usually the losers who can't find a real job who end up taking a lowlife job like that. they don't know their wrench sizes and despise anyone else who does.

after a 4 month hiatus from working on snow removal equipment and stoking a coal stove, today I got back to finishing this Gilson repair. The stove's been off and no plowing etc. since March. All the snow melted off here in early March and we never needed to remove any after that, a few small snowfalls melted away by themselves. Back then I bought a complete auger gear box with auger shaft, impeller, and impeller shaft in place, from Ebay, for $30 shipped, from an early 2 speed gear drive Gilson. The impeller shaft is straight, thank goodness. The early 2 speed had a 24" chute compared to the later 26" 55012, so I had to change that shaft out. Also had to tweak the ends of the impeller tips back to shape, they were bent the wrong way, as I'm going to keep the original early 2 speed impeller on there for now, it's in better shape than the original 55012 impeller. I'm going to have the impeller blades reinforced with weld. The blower drive unit is not yet mated to the chute, and the tractor is sitting out back, it runs but is separated from chute assembly.

*this repair taught me a lesson, if the original auger gear box seals and impeller on an early Gilson are in good shape, leave them be.* The bronze bushings are pressed in very tightly into the auger gearbox housing and cover, and trying to remove them with a drift and hammer, I boogered up the bushing on the 3 bolt cover. The impeller is also a very tight press fit on the impeller shaft. The impeller and bronze bushings require a careful press machine shop operation. Fortunately I have a spare 3 bolt cover from the original gearbox with an even better seal in it already. The seals are rather beefy and even with the original wobble, they didn't leak a bit.

the Gilsons are more difficult to work on than the friction drive Ariens or Cub Cadets, period. the auger gearbox seals and bushings easily push out on the Cub Cadet, they are a breeze to change. What I noticed is, the Gilson parts are not hardened as much, so they tend to ding or bend more easily. But the tractor section on the Gilson is built like a German Tiger tank. This will be fun to run this year in the deep stuff. Eventually I want to put paddle kits on the Cub Cadet and Gilson and do a back to back, see which one is the best machine in the snow- this winter.

tomorrow I'll probably get this back together so stay tuned. In 4 more months it will be in the 20's here again and the snow will be flying, so I'm getting an early start. The humidity is low and weather nice, rather do this work now than in 5 degree weather like last winter. I got hit with a pretty bad case of tennis elbow from working outside last winter, and the tops of my hands are still aching, probably a touch of arthritis. So these machines have to be running and serviced while the weather is warm, I don't want a replay of last year fixing the Gilson tractor in 6 degree weather again.


----------



## greatwhitebuffalo (Feb 11, 2014)

*back to business*

OK I've been dodging this repair like a lazy arse for long enough. over the weekend I disassembled the early 2 speed gear drive auger gearbox/impeller assembly, and straightened all the impeller tips, and had them all reinforced with weld. They were bent in the OPPOSITE direction so this machine ingested some big time rocks, newspapers, etc. to cause that much damage. I had to heat them all with a torch and bend them back the right way before they cooled, then have them welded.


----------



## greatwhitebuffalo (Feb 11, 2014)

pulled the original tine axle out because it was too short, the 55012 gear drive has a wider cut than the early 2 speed gear drive. here's a side by side comparison of the 2 axle shafts.


----------



## greatwhitebuffalo (Feb 11, 2014)

the pinion gear/impeller shaft has to be pulled to remove the tine axle and bronze driven gear, so while in there the gearbox was cleaned, bearings checked visually, then re-assembled trial fit. the pinion has to be pushed forward out of the case while on the shaft, then the tine axle with gear inserted, then the pinion walked back in while turning it, it threads itself onto the driven gear.


----------



## greatwhitebuffalo (Feb 11, 2014)

installed the correct wider cross shaft with bronze gear, snap ring, and thrust washers, and installed cover. I'm reusing the old seals, they are in good shape and the unit did not leak before, so it hopefully should not leak now either. the old side cover gasket was in perfect condition and glued to the case, so I just coated it with black permatex and bolted the cover on.


----------



## greatwhitebuffalo (Feb 11, 2014)

new mid-bearing installed with the old flanges and hardware, had to do some straightening on them first with a hammer and used a piece of old mine railroad track as an anvil. straight enough to use. these are a snap to install and the entire blower section is very basic and easy to reassemble with new parts.


----------



## greatwhitebuffalo (Feb 11, 2014)

ok here we go, ready for the trial assembly


----------



## greatwhitebuffalo (Feb 11, 2014)

in goes the blower drive assembly, and end bushings bolted into place. impeller shaft through the mid-bearing good alignment.


----------



## greatwhitebuffalo (Feb 11, 2014)

temporary hand installed the impeller pulley and keyway, and turned the drive system by hand, ONE impeller blade tip is rubbing on the top of the impeller housing/blower chute. I'm going to pull it back apart tomorrow and grind it just slightly for clearance. it actually went together a lot easier than expected, other than the welding, all this was done in one day, today.

next step will be install the lock ring on the mid-bearing, lock the impeller set screws, install the blower pulley and lock those setscrews, mate the blower back to the tractor section, install new shear pins (there's only bolts stuck in for now to trial fit it), reset the preload on the gearbox and install the cotter pin, fill the auger gearbox with oil, install the belts, and fire it up.

stay tuned


----------



## Grunt (Nov 11, 2013)

Nice job on getting the blades back into shape. Looks like that impeller would be a good candidate for an impeller kit to close up the gaps.


----------



## 43128 (Feb 14, 2014)

looks good. i agree with the impeller kit, you will be amazed at how much a 1/4 inch gap can affect performance


----------



## greatwhitebuffalo (Feb 11, 2014)

impeller kit is a definite for both my Cub Cadet 268 and the Gilson 55012 machines, but I'm going to try them first "as is" so I can see and measure the difference. It also depends on where you are located, I've seen some videos of big HP snowblowers with paddle kits, that were throwing snow 3 stories in the air as high as a large nearby home. Not good if you have close neighbors and catch a rock or other debris and toss it at high velocity into homes or cars. Fortunately I have no neighbors very close by on either side, so I can try it.


----------



## greatwhitebuffalo (Feb 11, 2014)

no rain and low humidity, so moving right along working outside today, buttoned up the blower section of the 55012 today. First off, one impeller blade tip had to be ground for clearance, it was hitting inside when it spun. Fortunately was able to turn it, and remove the chute, and clearance grind it with the small grinder through the chute exit opening. Then it cleared. Lucked out there, didn't have to pull the entire drive and gearbox again to grind it.


----------



## greatwhitebuffalo (Feb 11, 2014)

the belt drive pulley on the blower was slightly damaged previously, while removing it last winter, a small piece of the pulley belt groove area broke off. I was able to have this cast piece welded back in with nickel welding rod by a local welder, and then hand ground it to the correct contour. Installed the pulley just hand tight on the locking screws for. now, as it has to be aligned with the upper pulley when mated to the tractor section.


----------



## greatwhitebuffalo (Feb 11, 2014)

lock collar installed on the mid-bearing. to be honest I think the lock collar is something that is overkill. The entire drive system it held in place firmly by the side auger tine axle bushings, bolted into the chute. Ariens and Cub Cadet don't use a lock collar, just a bearing held in place by 2 half flanges with bolts in the same way. But I installed the collar anyway. It is insurance that the shaft will not spin inside the bearing inner race, but it's also insurance that over time, the locking collar will corrode and rust on there, and be nearly impossible to remove- again- without heating it with a torch. A simpler system like a Cub Cadet here would be way better. but oh well.


----------



## greatwhitebuffalo (Feb 11, 2014)

taking a look down inside at the replaced impeller and axle, everything looks ready to rock n roll in there.


----------



## greatwhitebuffalo (Feb 11, 2014)

(whew)... filled the gearbox for auger with gear oil, installed the fill and drain/sight plug. set the preload on the auger gear box bearings, and cotter pinned it. had to go buy two new shear nuts/bolts, and installed those. the 2 spares I had for the Cub Cadet were too short.

next was, install the lower cutter/scraper bar. turns out all the old nuts were junk, of course, but the flathead carriage bolts were useable- after I ran a die on each one, to clean the threads. I didn't want to try to find those special flathead bolts at the hardware store. installed the bar with 5 nuts from my hardware junk bucket, and found out, the ends of the bar were hitting welds in the chute, where the corners were welded by my welder, when I first started this resto. Had to remove the bar, and grind the welds flat, so the bar would bolt to bottom of chute flat. Guess what, it STILL was not flat, as the bottom surface of the chute is heavily pitted, rusted, and beat up from use, and getting thin.

did a little bodywork with the hammer, then slid the bar all the way back, bolted up up tight, and went across the bottom of the chute with vice grips and crimped all the bends and dings and lumps flat again. Finally it went on there straight.

then noticed, the right side skid had the nuts installed on the INSIDE of the chute, by previous owner, and they were dangerously close to that tine when turning, so had to remove those nuts, and them around, putting the bolt heads on the inside. Well that was a project too, as the nuts were stuck fast, and after getting them off, had to run a tap in them to clean them up. 

the LAST STRAW was, while turning the tines, I noticed the left side tine was scraping the chute inside in a few places. that tine obviously ingested something at one time, and caused the bent impeller shaft- and the tine is visibly distorted in a few places. I marked where the tine was scraping the chute and slightly ground the tine edge for clearance in 3 places. then it cleared.

so FINALLY the blower/chute assembly is together, ready to be mated to the tractor ! as you can see, this repair took a long time, and I did nothing cosmetically, only mechanically fixed it. Imagine if you had to also strip/paint it. (no thanks) amazingly the Gilson was runnable and would have blown snow the way I got it, albeit haphazardly and who knows how long- but that is a testament to how well it was built in the first place.

This was like repairing the USS Yorktown after the Battle of the Coral Sea, to get ready for Midway. Complete with bomb craters, shell and torpedo hits. the sturdiness of the Gilson design was able to take 45 years of abuse and neglect from outside storage in wicked Connecticut winters, and still have enough remaining structure to fix and restore it.

stay tuned, next will be mate to tractor and fire it up.


----------



## greatwhitebuffalo (Feb 11, 2014)

*back together*

55012 is back together now. 4 bolts to connect blower to tractor. measured the belt spacing on the motor pulley, it's about 7/8". flipped the machine on its nose, and set the same spacing on the pullleys underneath by sliding the blower pulley back about 1/8" then locked the set screws. I had filed/cleaned up the pulley hole and keyway to make sure it would adjust easily at this point. The correct belts go on the machine with ease. After that it was a simple matter of connecting the blower idler tension spring, and putting the belt cover on. I left the airbox off the engine for now. greased the base ring then installed the chute.

here it is assembled


----------



## greatwhitebuffalo (Feb 11, 2014)

*video running*

it's running once again- notice the clutch works now with the proper length belt, it will sit in 1st gear and not move, until the safety handle control is squeezed


----------



## dbert (Aug 25, 2013)

GWB
I just wanted to say I really appreciate all your well documented and photographed threads.


----------



## greatwhitebuffalo (Feb 11, 2014)

dbert said:


> GWB
> I just wanted to say I really appreciate all your well documented and photographed threads.



thanks, I look at it as a 2 way street, I read the forum and other webpages and find parts, and repair tips, all the time. so it's good to write these up so the next guy can do the same. quite a few repairs in the past, the net threads got me out of hot water by steering me in the right direction, where otherwise I would have been lost, or taken a lot longer/more expense to do the repair. it makes a good database. so I try to put back in as much as I get out.


----------



## greatwhitebuffalo (Feb 11, 2014)

here is the "before" video showing how badly the front auger gearbox was shaking around, due to the bent impeller shaft. It was a lot of work just to take that wobble out of the blower section. 





 

If the mid-bearing and left tines were not seized in the machine, and I could have found a complete auger gearbox/shafts to swap in at a reasonable price, this would have been an easy fix. But the complete drives I did find for sale were $150 plus shipping, more than what I paid for the whole machine to begin with. The mid-bearing being seized, made the repair more difficult, as the front end drive would not just pull out of the machine easily. The seized left tine was the hardest thing to get off, it had to be removed in a press, it was stuck fast on the cross shaft that went through the gearbox. 

thanks to Pete at the Gilson Snowblower Shop in Maine, and his highly informative website, that gave some valuable tips along the way. When I found the early 2 speed gearbox w/axles on Ebay on the cheap, he verified the box and impeller shaft is the same, but the cross shaft was shorter. Then I knew it would work after swapping the cross shafts.


----------



## greatwhitebuffalo (Feb 11, 2014)

*bronze gear issue- auger gearbox*

I had forgotten to put up this pic earlier, it was in my other camera. This shows the auger drive gear from the early 2 speed Gilson on the left, and the original 55012 gear drive auger gear on the right. Notice the 55012 gear on right had the damaged, worn, and cracked keyway. It would have ran that way but I used the better early bronze gear instead, and kept the original beat up 55012 gear as a spare.











close ups of each gear, take a good look at the keyway condition of each, just another thing to look at and be aware of


----------

