Removing a stuck gear?

[Canuck750]

I have been fighting a stuck gear seized onto a tapered shaft (pinion gear on end of crankshaft) on a small Benelli motor I recently picked up. I have a proper clam shell type bearing puller that splits in half and gets under the gear and the threaded pin that applies pressure to the end of the crank to lift the gear off.
Usually the gear will pop free with a few turns of the thrust pin but the gear is clinging on for dear life!
I have tried soaking with penetrating fluid and even heated the gear up with a propane torch, it will not budge even with my 1/2” drive impact pounding away, there is a lot of pressure being applied to lift the gear off the shaft, just not moving.
I put the whole bottom end of the motor into an ultrasonic cleaner filled with a mild rust remover (Evaporust) and will leave it vibrating away for a couple hours.

Anyone have a ‘trick’ forvgetting a stuck gear off a tapered shaft?

Thanks
Jim

[RinkRat II]

     
        Hi Jim, The only flaw (if there is one) in your technique I see, may be you're not getting the gear hot enough quick enough. The propane may be a little light to do the job. An oxy/acetylene setup will get the gear hotter quicker and the  expansion of the gear will be quicker.  I've also had success with several heat/cool cycles while leaving the puller applied . My $.02

     Paul B

[nc43bsa]

All that plus giving a good rap with a brass or copper hammer on the end of the puller bolt.

[cliffrod]

When it’s really stuck and the normal BFH or torch- hot/cold or penetrating fluid or ?? method isn’t doing it ..

Load the puller.  Then use a smaller hammer to tap, tap, tap the loaded puller bolt, chrome tie rod boss or whatever.  Sometime this takes 20-30 taps.  Sometimes it takes 20-30 minutes (or more…) of continuous tap, tap, tap, almost like your letting the hammer bounce on the part under its own weight.  Just keep going.  If you need to tighten the puller along the way, do it to keep tension on the parts.   It’s SOP to separate special parts like chromed tie rods on hot rods and I’ve found it works great on fragile unobtanium parts.  You can use a bigger hammer, but I have a very small ball peen hammer that I use for this to avoid damage. 

With some things like those tie rods ends, a second hammer on the opposite side serving as an anvil with another hammer tapping on the other side works well too.  When it seems like it’s taking forever and then just lets go, it’s a great feeling.

Good luck, Jim.

[Canuck750]

Thanks for the tips guys!

Tomorrow I will try the hammer tap method, I am a little scared to break out the oxy/acet torch, I really need to save the crank and gear. The rotor is also stuck on the other side of the crank. The proper puller is not moving it. I will try tapping the bolt of the puller on it as well.

This motor looks like it was buried in a swamp


Jim

[nc43bsa]

Do you have the bike the motor goes into?

[Mike Tashjian]

Just did a timing belt on my Honda pilot. The bolt in the Harmonic balancers are crazy tight.  Tried all the regular methods, holding the balancer, gun with 1400 ft lbs in reverse with a weighted socket. No go. Saw a guy use a Oxy Acetylene torch on the bottom edge of the bolt and washer under.  High heat with the cutting head turning the bolt lower edge orange and the washer orange. Probably could have used my finger to loosen it as the gun never even impacted, just spun the bolt right out.  A quick spray with a water bottle and the bolt was fine and the balancer was warm but not in the least bit bothered.  I would try some high heat fast and see how that does if all else fails. 

[cliffrod]

The tap tap method has helped me more than once.  When it didn’t seem to work & I got tired of doing it, I left the assembled part & puller in place loaded in full tension, added a little more ATF/acetone homemade penetrating fluid and did something else.    When I came back hours or days later, either the part had come loose on its own or surrendered after more tap tap tap.

Regarding high heat, I had one failure worth mentioning.  When trying to remove a failed bearing on the rear axle of a Toyota truck, we used a torch to heat it.  The heat applied was well below the typical point of melting, but was apparently enough to fuse scored material (that was apparently why the bearing would not budge) on the contacting faces & effectively weld the bearing to the axle. After cutting off the bearing, we had to replace the axle.  Just something to consider.

[SIR REAL ED]

In the past, I've used a spring loaded prick punch to apply thousands of those "little taps."  With bit of practice, you can sound like a little machine g?n.   

The other thing to do is to use a propane torch to heat the outside part just outside of the joint, not a lot, just to 300 degrees or so, then apply a good penetrating oil (I prefer Deep Creep) at the joint, where it will boil off and hopefully some will penetrate into the slightly wider joint that the heat creates.

Leaving the puller on under tension is a great practice to follow.

time is on our side, patience is a virtue, and alcohol sometimes helps also.....   

[John A]

Sometimes I will take a candle and put it on the heated parts. The wax wicks it way into the joint as it melts . I learned this stripping engine blocks for cores. It seems to work somehow differently than penetrating oil with heat. Tapers can sure get stuck, especially when you don’t want to hurt the parts!

[SIR REAL ED]

Another quick thought get a container big enough to submerge the assembly.  Put enough "Ed's Red" (50% Acetone/50% ATF) in it to to cover the part.

Put the part in the oven and heat to 350-400 degree for a half hour or so, then put the part in the Ed's Red solution for an hour or so.  Then repeat as needed.

Do this outside.  I suspect that Acetone has a pretty low flash point.

[Don G]

Why not set it outside over night with tension on the puller ((going to be -20 pretty quick), bring it in and heat the gear, give the puller a whack, if it doesn't move place it back into the cold and reapply the heat and shock again, eventually it will pop loose.  DonG

[Huzo]

If you do get around to applying “heat shock” to the pinion, is it possible to submerge the whole lot in water with just the pinion above the water line ?
This is to keep the shaft chilled while the pinion is hot, increasing the effect of expanding the gear away from the shaft.

[Canuck750]

The 'before' picture, a big box of joy arrived via UPS this week, a box only a gear head could love



The engine sat in the ultrasonic cleaner overnight in Evaporust, it was pretty clean this morning but neither the crank pinion gear or the magneto were in the mood to leave the engine behind despite my best coaching with pullers and a big impact.

The magneto did eventually come free with a lot of small taps with a brass hammer on the end of the puller bolt torqued down as much as the impact would deliver, it came free with a thud, shot up a couple inches and gave up.



The crank pinion was another beast, one of the puller leg threaded studs snapped clean off from the pressure but the pinion did not budge.



After replacing the puller leg I took the block to the welding table, crossed my fingers and struck up the oxy/acet, a slightly carbon flame and with the puller cranked to the nines I touched some heat on the gear, bang, almost immediately the puller and gear literally flew off the crank shaft end and fell to the floor. Success!

The crank feels real good, it was the crank I needed most for another engine, stator and magneto and some gears and hopefully I will finally have a complete 200cc motor for my Beneli / Motobi build.

Everything stripped and vapour blasted, lots of parts to now sort through and pick the best between two motors

[SIR REAL ED]

Glad to hear the problem is solved.   

After I left I thought about using an air chisel with a hammer bit to deliver lots of taps.  Turn down the air pressure to get the amount of hit you want.

Heat, time, chemicals, chemicals, force, and patience are beautiful things.

[Muzz]

I love it when a plan comes together.

[John A]

Beauty.