Crank shaft clearance 036

[paladin]

I just finished installing crank bearings for the first time thanks to this site. It seemed to go just fine, I searched all the info on doing this and used Lakesides way on the pto side bearing installing it in the case first pressing it in so it stopped with the oil pump mounted on the case then pulling the crank into the bearing till it bottomed I used the clutch center and a little heat and cooling and it went good. Then I installed the bearing on the flywheel side of the crank useing some heat and cooling not a problem, then heated the flywheel side case and put it all together (with the gasket) and installed the bolts went great useing Pioneerguy's info. I tapped on the crank to free it a little seems smooth it rotates with your fingers a little drag but no tight spots. What I did notice is the Pto side of the crank is very close to the case not rubbing but you only have about .009" clearance between the crank and the case and the flywheel side has quite a bit more. All bearings and the case gasket are stihl oem. I also install the oil pump it sits right on the case flat and installed washer,oil pump,gear and clutch washer and clutch to make sure oil pump gear spins free and it does. So is something wrong with that clearance or is it normal? Any info appriciated and Thanks in advance.

 

[pioneerguy600]

Did you use the Stihl properitary bearing on the pump/ clutch side?
The non prop. bearings are not as deep.
Pioneerguy600

 

[paladin]

I used the bearing as per the ipl for the clutch side from the dealer, it is kind of off set for the oil seal to fit into and the lip on the outer edge to fit the oil pump. I don't know the number off hand but it was not a normal looking bearing like the one for the flywheel side.

 

[pioneerguy600]

That sounds like the correct one, I have seen where the wrong bearing has been used, it was less deep and it allowed the crank to end up too close to the clutch side of the case as the oil pump is used as the stop to set the rest of the crank into proper position. If the crank throw seems too close I would just tap the clutch end of the crank back until both sides have close to the same clearance. The clearance is tight on both sides but 9 thou seems a little too close to me.
Pioneerguy600

 

[paladin]

Would I need to back off the case screws to do that? Would I be trying to move the just crank or the crank and the bearings? Would that start throwing off how the oil pump mounts and works. I kind of thought to move the bearings to give more clearance,but then the pto side would not be against the pump like they tell you to install it. Both bearings are all the way in on the crank like you show in your post on installing them. Just you can see more of the flywheel side bearing in the case between case and crank than on the pto side.

 

[pioneerguy600]

If there is no danger of the crank throw hitting the side of the case then it would be better to leave the bearing set against the pump body as stated in the Stihl manual. If otherwise then the crank and its bearings will move over if the end of the crank is tapped over toward the flywheel side.
Pioneerguy600

 

[paladin]

No when I spin it, it does not rub it just seemed close to me also.I was wondering when it is run and heated up in operating conditions if it could rub ,and both sides not being even would cause a problem. One thing I did notice is the outer bearing races run a very close tolerance to the crank throw when the bearings installed all the way on the crank. So if that tolerance is all right maybe this will be also. I will look it over some more any other ideas or imput is much appreciated.

 

[pioneerguy600]

Not likely to rub when it is heated, the crank would expand toward the flywheel side, the oiler stops all movement toward that side.
Pioneerguy600

 

[paladin]

Thanks I am not putting the rest together quite yet I will look it over more to see if I overlooked anything else. Any other ideas let me know.