Proper stator removal technique

[stuartjbecker]

I have a question about how to properly remove a stator to gain access to the hall sensors in a Crystalyte rear motor.

I have a Crystalyte 5304 which I am replacing the hall sensors in (one has burnt out). I pulled the motor cover off the non-drive side, and found out that the hall sensors are actually on the other side.

Hmm..Need to get to the other side..

I could get to that side by removing the cassette and prying up the other cover plate, but that seems like too much work, because the cover plate on that side is inset. The other, better option I believe is to pull the stator up and out from the non-drive side. I have read that you can do this by stepping down on both sides of the wheel's rim, pushing the stator up enough so you can lift it out. Unfortunately mine wouldn't budge.

Am I going about doing this properly? If so, it looks like I will need a proper tool: a 10" 3 jaw gear puller. But 10" ones seem hard to find; neither Sears or any of my local auto shops have them.

Stuart

 

[Gordo]

Do not try pulling it out with your hands. Use a large 3 jaw puller. When the jaws are set correctly tighten up the jaw bolts snugly. It is also safest to assemble the motor by using the puller to ease the stator back into the wheel.
Have you tried Harbor Freight for a puller?

http://www.harborfreight.com/3-piece-three-jaw-puller-set-32184.html

 

[dogman dan]

Should pop out when you stand on the rim. But you may have to tap a knife blade into the cover to get the sealant to release.

I'm assuming you have already taken one cover off, and that you have the open side down. Handle it by the axle, don't grab the cover. You can pinch a finger nearly off.

 

[stuartjbecker]

Gordo: Harbor freight only sells up to 8" pullers.

Dogman: I'm trying to get an exacto knife in there, but there's not even room to do that. Just to clarify, when stepping down on the rim, the side w/wires will be facing down, and the side w/the cassette will be facing up, correct?

 

[dnmun]

yes, put the axle nut back on reversed on the end of the axle so the threads are not exposed and whack firmly against a block of wood on the concrete. that's how i get the cover off the other hub motors so i think the C'lyte is the same. or put a dowel or piece of wood through the holes in the stator and knock the cover off the other side from inside by whacking with a hammer on the end of the dowel. but if you have to replace the hall sensors then you have to get the stator out of the hub i think. maybe double check to make sure they are dead first and not just a bad connection. i have pushed out the golden motor stator, but that was a full scale push with both feet to get the stator clear of the hub magnets and C'lyte has even bigger magnets.

 

[ZOMGVTEK]

I could just finesse my Golden stator out without removing the other side cover or using a puller. I just needed to grab the axle and give the other side a light tap on concrete as I pulled up. It was really quite easy.

This motor might be a bit different from my GM, however.

 

[stuartjbecker]

Thanks; but before I start banging away I need to verify I am removing the stator in the proper direction. Lets say I have the drive side with the cassette on it down, facing the floor. The side with my cover off, and with the wiring coming out, is oriented upward. Should I be pushing the stator out upward, or downward?

I appreciate all the help. Learning as I go!

 

[ZOMGVTEK]

Its just sitting there. The only thing holding it in place is the magnetic field and the two bearings in both side covers. One cover is gone, you're left with the other sides bearing, and the magnetic field.

There should only be one way to get it out, you want to pull in the direction of the missing side cover to separate it from the wheel/side cover. The magnetic field is fairly strong, so its going to want to slam right back into place.

 

[dnmun]

you can tap on the inside of the opposite cover through those holes in the stator, and once it is loose it will slip off. the stator is held to the hub magnets by huge magnetic force though, and that C'lyte has bigger magnets than the goldenmotor or 9C so it will be more force to remove, imo.

that's why i recommend double checking the hall sensor when you get the cover off on that side. check continuity from the leg of the halls back up to the controller, just in case it is a bad connection somewhere in that lead. unless you shorted the hall sensor to the phase voltage, it should be ok, and more likely a bad connection so you would not have to pull the stator then, or replace the hall sensor.

 

[John in CR]

I couldn't find a big puller either, so I just made 6 new and longer flat pieces to extend the reach. I clamped them together for drilling the bolt holes to be sure their reach was identical. FWIW even doing it manually I would never stand on the wheel, because you can't get the force parallel with the axle that way. A vise to hold the axle vertical or a helper to hold the wire end of the axle, so the stator doesn't fall over once the rotor clears the stator make manual removal a snap. Using a vise put some small flat pieces of steel between the axle flats and the jaws of the vise to avoid damaging the flats. With a vice you can even push the rotor off toward the wire side if you want, just don't clamp the vise too tight with a thru axle wire rig.

I've even taken apart big scooter hubbies with far more magnetic attraction than an X5 with the manual method using a vise, and a vise gets a lot more use than a 3 jaw puller, so if you have neither, get a vise and a cheap pair of welding gloves instead of a large 3 jaw puller.

 

[ZOMGVTEK]

Theres lots of ways to get it done. All you really need to know is its basically just held in by magnets. My Golden Was fairly easy to remove. A light smack and it came out. The magnets on it are nothing serious, and the thing gets burning hot all the time, so they might be weak. You just need sufficient force to get the thing out of the magnetic field. Getting it back in is really easy. Slide the axle back into the bearing, and it will violently smack itself right into place.

 

[Gordo]

I couldn't find a big puller either, so I just made 6 new and longer flat pieces to extend the reach. I clamped them together for drilling the bolt holes to be sure their reach was identical. FWIW even doing it manually I would never stand on the wheel, because you can't get the force parallel with the axle that way. A vise to hold the axle vertical or a helper to hold the wire end of the axle, so the stator doesn't fall over once the rotor clears the stator make manual removal a snap. Using a vise put some small flat pieces of steel between the axle flats and the jaws of the vise to avoid damaging the flats. With a vice you can even push the rotor off toward the wire side if you want, just don't clamp the vise too tight with a thru axle wire rig.

I've even taken apart big scooter hubbies with far more magnetic attraction than an X5 with the manual method using a vise, and a vise gets a lot more use than a 3 jaw puller, so if you have neither, get a vise and a cheap pair of welding gloves instead of a large 3 jaw puller.

As you found, you don't need a very large or strong puller, just a long one. I'm going to cut some rings out of 3/4 plywood and try all-thread (Redirod) next time, just to see if it will work. I already have close to a dozen pullers including ones for pulling marine propellers upto 40".

 

[lowimpactgardening]

Hi , im new on endless and wanted to introduce myself firstly !This is a great place for newbies to learn the tricks and techniques of repairing our ebikes.
My question has to do with replacing my frayed motor cable. Where the cable comes into the axel is where the sheath had worn off some of the wires and this basically said to me i need to replace IT. I followed a another post in this forum step by step , got the cover off and stator is almost out , having a little trouble getting it the last 1/4 out of housing. I know there is a magnetic hold on it , did the whole stepping down on the rim , but cant seem to get it to come completely out.
Hope this doesn't seem to redundant.

Thanks for any help.

 

[dogman dan]

Could be hung up on the bearing on the cover, assuming you don't have both covers off already. Or just that those magnets are that much stronger than you expect. Strong enough to just about snip off a finger if you don't watch out putting one back.

probobally you just need to pull harder. But it points out why I love using a puller to make it not only easy, but in perfect controll.