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Tips or Tricks to get a gear off a shaft

66promod

Plastic
Joined
Mar 11, 2022
Hello professionals. I’m having a hard time getting a gear off a countershaft in a transmission.

It’s an interference fit and the manual warns it will take up to 20 tons to press it off.

However, I’ve tried 20 and a 100 ton presses with heat on the gear core and still won’t budge.

It did break a few teeth off unfortunately, so I stopped there for safety and to keep from ruining the shaft.

I’m hoping for some tips or tricks from the machinist community of professionals - someone has to have faced and conquered this kind of issue.
 
Hello professionals. I’m having a hard time getting a gear off a countershaft in a transmission.

It’s an interference fit and the manual warns it will take up to 20 tons to press it off.

However, I’ve tried 20 and a 100 ton presses with heat on the gear core and still won’t budge.

It did break a few teeth off unfortunately, so I stopped there for safety and to keep from ruining the shaft.

I’m hoping for some tips or tricks from the machinist community of professionals - someone has to have faced and conquered this kind of issue.

If the gear is toast, put it in the lathe and machine the gear off.
 
Heat the gear while keeping the shaft cool, while in the press, use an oxy acetylene torch, not a propane plumbers torch. Or use an angle grinder and cut thru the gear, get as close as you can to shaft without hitting it, then drive a wedge into the cut to break the last bit.
 
Its possible the key has sheared and the gear spun ...in which case there will be a ring of friction weld.........anyway,I would carefully cut from the keyway out to the teeth.....if you are reasonably proficient with oxy,this should not damage the layshaft.........however ,if a gear has spun,the shaft will be cactus anyway........I have rebuilt hundreds of truck boxes,and the main cause of broken layshaft teeth /spun gear is COASTING IN NEUTRAL.
 
Yeah that doesn't sound good; if a 100T press didn't budge it - especially with heat - you have a major problem. If there's a keyway I'd second the recommendation to cut through to the key with an abrasive cut-off wheel at the keyway and also at 180° opposite. On the 180° side don't cut all the way through, just close. Then give it a tap or two with a hammer and chisel to push the cut line apart on the key side and it should split and fall right off. If no keyway, cut almost through at two spots about 180° apart and tap in the cut line with a chisel and hammer (or better yet air hammer with chisel) to split apart.
 
I had a friend who had once lived in Kansas City. He told a story of a used Ferrari that had been bought and sold and had been around at various car lots and was now for sale again at some place. A couple guys decided (maybe after a few beers) that they were going to steal the thing. So they backed up to it, looked both ways, hooked up a tow chain and headed across the state for St. Louis. What they didn't know was that Ferrari has a transmission oil pump run from the mainshaft, so all the time the car was being towed the transmission wasn't getting lube. Somewhere part way across Missouri the thing just froze up. So they pulled off to the side, unhooked it. pulled out a revolver and said "Poor old horse" before putting several bullets into the hood.

The buddy said that it was recovered and repaired, and you could see the welded up holes in the cam covers.
 
I had a friend who had once lived in Kansas City. He told a story of a used Ferrari that had been bought and sold and had been around at various car lots and was now for sale again at some place. A couple guys decided (maybe after a few beers) that they were going to steal the thing. So they backed up to it, looked both ways, hooked up a tow chain and headed across the state for St. Louis. What they didn't know was that Ferrari has a transmission oil pump run from the mainshaft, so all the time the car was being towed the transmission wasn't getting lube. Somewhere part way across Missouri the thing just froze up. So they pulled off to the side, unhooked it. pulled out a revolver and said "Poor old horse" before putting several bullets into the hood.

The buddy said that it was recovered and repaired, and you could see the welded up holes in the cam covers.

I never got that mentality. Like, if someone breaks in and can't get your TV off the wall, they break it. "Well if I can't have it, you can't either!"
 
Hello professionals. I’m having a hard time getting a gear off a countershaft in a transmission.

It’s an interference fit and the manual warns it will take up to 20 tons to press it off.

However, I’ve tried 20 and a 100 ton presses with heat on the gear core and still won’t budge.

It did break a few teeth off unfortunately, so I stopped there for safety and to keep from ruining the shaft.

I’m hoping for some tips or tricks from the machinist community of professionals - someone has to have faced and conquered this kind of issue.

Depending on what the gear is made of, either split it with a bandsaw if it isn't hardened OR a grinder if it is. Portaband would work well if it isn't hardened and you have the clearance.

That trick works well for bearings stuck on shafts, too.

If 200,000 pounds didn't make it budge, it prollys not gonna come off on its own.

Any chance this shaft came out of a piece of heavy equipment? Just occurred to me that we may be talking about a transmission out of a huge tractor, no necessarily a car transmission.
 
Any chance this shaft came out of a piece of heavy equipment? Just occurred to me that we may be talking about a transmission out of a huge tractor, no necessarily a car transmission.

Name= 66ProMod
Number of posts = 1
Registered: today
My guess: transmission from his dragster
 
Clean it shiny bright with abrasive, give it an acid etch with naval jelly or whatever you have.

See if you can see weld material.



What kind of heat ? valid point oxy fuel ?
Did you get it hot enough to release any loctite ?
 
LOL

I may or may not have learned this the hard way. Wasn't a snap ring, it was a set screw, but I think the lesson (and the resulting broken cast iron) is the same.

Myford (Brit hobby lathe) used to have a ''dirty trick'' with grub / set screws ;- put one on top of the first (I assume as a locker) folk remove one screw but not the second ... over the years I managed to save a few of such jobs brought to me, but more often than not the irrepairable damage had already been done.

Then many of those unfortunates / morons (you choose) had to sit down when finding out the cost of replacement parts. :D
 
Myford (Brit hobby lathe) used to have a ''dirty trick'' with grub / set screws ;- put one on top of the first (I assume as a locker) folk remove one screw but not the second ... over the years I managed to save a few of such jobs brought to me, but more often than not the irrepairable damage had already been done.

Then many of those unfortunates / morons (you choose) had to sit down when finding out the cost of replacement parts. :D

Yeah. I don't believe in doubling up set screws. I get it, you REALLY don't want that set screw coming loose! Use f'n Loctite.

I should say, my "OOPS!" moment was with a cheap import drill press. Now keep in mind, I was probably 15 years old. It had an underpowered motor. I could stall it fairly easily with a 1/2" bit in steel. (That's 12.7 milomiters for you euro types :D) I wanted a smaller pulley to get the RPMs down (that's RPMs for you euro types). So, I did the obvious thing and tried to pry it off. Nope! I figured it was pressed on or something (again - 15, I guess?). SO, since I couldn't find a gear puller to fit it, I grabbed the pickle fork (ball joint separator... Brit. LOL) and a big hammer. OOPS. Cracked the pulley.

I actually ended up making a making a pulley out of two big washers that I "dished" in a vise with a pair of sockets as dies. Welded them together and welded them to the shaft. Worked well, honestly.

I still have most of that drill press.

I actually found the chuck for it yesterday. Think I might make an adapter to put it on a bench grinder spindle. JT-whatever to 1/2"ish by something left hand thread.
 
I once got a boat propshaft to replace.......the shaft was 1 1/4" stainless,the bolt up coupling was a giant blob of steel,weld ,rust ,and broken off setscrews.....and hammered somewhat........anyhoo,I cut the shaft off as it was bent and scored,and pressed out the stub shaft from the coupling........I heated it hot enough to smoke the loctite it was smothered in,and just a simple keyed shaft flange took nearly 100 tons to come out........I always saved the propshafts with ,bent and sheared keyways...hiding under the crap was an ocassional monel shaft....near pure nickle.
 
I once got a boat propshaft to replace.......the shaft was 1 1/4" stainless,the bolt up coupling was a giant blob of steel,weld ,rust ,and broken off setscrews.....and hammered somewhat........anyhoo,I cut the shaft off as it was bent and scored,and pressed out the stub shaft from the coupling........I heated it hot enough to smoke the loctite it was smothered in,and just a simple keyed shaft flange took nearly 100 tons to come out........I always saved the propshafts with ,bent and sheared keyways...hiding under the crap was an ocassional monel shaft....near pure nickle.

Why nickel in a prop shaft?
 








 
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