new engine build, crank not centered in case?

[lt1bird]

boys, im building a new motor. The crank seems to not be centered properly. If I push the flywheel side bearing all the way left, up against the case stop, the crank seems to be offset way to much to the flywheel side. See how close the crank is to the case on the right, then a big gap on the left. also see the center bearings are offset to the left to much. Now, is this a problem with the flyweel side bearing not pressed on enough or am I supose to simply center the crank by eye and hope the cases torqured together will hold the crank centered. Putting a gap on that flyweel side bearing does not seem cool. What keeps the crank from walking out of position? can someone let me know what the proper fix would be? Thanks again!

 

Edited May 23, 2010 by lt1bird

[firebanshee]

Do you have the that half circle retaing clip in the case that goes in the groove cut in the outer bearing race?The retainer goes in the bottom case half and sits in the groove on the bearing to keep it were it belongs.The other bearing should have a little pin sticking out of it that goes in a notch.

Edited May 23, 2010 by firebanshee

[lt1bird]

No, this crank does not have a clip on that side, just o-rings on all the bearings. The gear drive side has a TZ style bearing... with oring still...no clip

Edited May 23, 2010 by lt1bird

[bansheesandrider]

No, this crank does not have a clip on that side, just o-rings on all the bearings. The gear drive side has a TZ style bearing... with oring still...no clip

That is your problem, you need to have a bearing that takes the clip to hold everything in position.

[lt1bird]

I could do that. Put a clip on the TZ bearing and push the crank all the way to the TZ bearing side(everything lines up mice like that). There is a 1.5mm gap on the flywheel side bearing to case fitment. Maybe its not an issue to have this little gap on the flywheel side bearing? anyone else see this gap issue?

[AKheathen]

hmm, interesting way to line mice up...........you don't need a new bearing, just pop the o-ring off and put the circlip on.....the o-ring bearings are actually circlip style bearings that someone just put o-rings on...the thing about the tz, though, is that it's better to run the circlip on another bearing to get the sideload off of it

[lt1bird]

I know about the orings replacing the pins for alighment.....I dont think they are meant to replace cir clips though. On the TZ bearing, there is no side load. Streight cut gears create not side load. Now, a TZ bearing with heli stock gears would be trouble.... with my setup, usin it as is, there would be nothing to keep the crank from moving side to side other than the case's sandwiching the bearings in place. Even a clip on the TZ bearing would only stop the crank from going to far toward the clutch side. It would still move that 1.5mm to the flyweel side. Not sure it could or would really happen......

[AKheathen]

the locator pins are just to keep the bearing from spinning, you only need the one bearing to keep the crank from walking. the cases should take the load of keeping everything in place when you bolt it together, and the circlip will be a locator, basically. straitcuts- i wouldn't hesitate rippin the o-ring off and putting the circlip back on, like it's supposed to be

[lt1bird]

I can add the cir clip to the TZ bearing. This will keep the crank from walking to the primary gear side. There is noting that will keep the crank from wlaking to the flywheel side. This will cause the rods to be not centered in the bore. Do you think the bearing on the flywheel side is not pushed all the way onto the crank? Thats the only thing I see that would cause this.

[lt1bird]

OK, here is the picture of the crank in the proper position. A c clip in the TZ bearing for location and the crank pushed all the way againt the TZ bearing.

 

 

See the gap that left over. If the bearing on the gear side was not a TZ style I would be ok with it, but the TZ bearing does not hold the crank in place, it floats. Something else needs to keep the crank in position. Am I counting on all the orings on the center bearings and the engine cases to hold the crank in place? That seems a bit sketchy.... I would probably put a shim in that gap so the crank will not walk over to that side causing the crank to be way out of center. anyone else using TZ bearing notice this? My TZ bearing (roller section) will pull right off the end of the crank, is that correct?

[AKheathen]

well, the porper thing to do is have the case machined to accept a circlip on another bearing

[lt1bird]

yes, that would seem like a good solution. PITA but would most definatly be the proper thing to do

[pabansheematt]

I had the same problem with my tz bearing. I ended up getting rid of it.

[lt1bird]

Ill call trinity and see what they say. Did you get rid of it beacuse you did not want to machine the cases?

The crank cant go past the TZ bearing...ok on that side. im looking at simply putting a spacer on the flywheel side so the crank cank walk that direction either.

[No Limit Powersports]

Im not sure what tz bearing that you have but the oem style ones that we run have a groove for the circlip. The inner bearing should be pressed on all the way to the crank cheek on both sides.