Wide frame PTO OK on a Narrow frame?

[mike melillo]

Originally Posted by tonka.scout800a

Reading the service manual and preparing to install my PTO clutch bearing. It states :
"Be sure to lock the collar to the bearing in the direction of crankshaft rotation"
on page 2-44 of the 1x2-3 manual
Guess I need to take the old one off so I will understand what that means exactly.

Your correct about what the manual says, and now I'm questioning if thats correct, or I'm wrong. (I'm sure everyone will love that comment, can't wait to hear the feedback)

Any way, looking at the PTO from the front, the engine spins counterclockwise (to left). If you lock the collar in the same direction (to left, counterclockwise) you're relying on the set screw to do all the work. The concentric locking is trying to be unwound from the rotation of the engine.

Conversely, if you lock the collar to the right (clockwise) it's going against the rotation and as the engine is turning its always applying rotational torque essentially tightening the collar as the engine runs.

The only exception to this would be timing misfire and the engine spontaneously rotates in the wrong direction, like when is sheers the flywheel key.

Lets hear what others have to say. I don't claim to know it all, and I sure have made my own mistakes, but this seems pretty straight forward.

Moving past this for a minute to the core problem that TheSaturnV is experiencing; In thinking this over a bit, another theory could be that the thrust button is making contact with the crankshaft.
There too, check your dimensions on the parts that are different from when it worked, and check to see that the bearing has the sir clip and is not sitting too far back on the crank.


Mike

[OffTime]

The service manual is correct. As long as the bearing spins freely, you may never notice any difference. However, the purpose of the lock collar is to lock the bearing to the shaft. You want the collar to be locked in such a way that the normal rotation of the crankshaft keeps the collar tight on the bearing. If the lock collar was to be locked opposite the rotation of the crankshaft, being that the set screws lock the collar to the shaft, any movement in direction of normal rotation would unlock the collar from the bearing. Lock collar must be locked counterclockwise or in same direction as rotation of the crankshaft.

[DoubleO7]

I have removed original factory bearings and just installed a new bearing and they did not have any clip of any sort that would prevent the bearing from going onto the crank any amount. You could install it "eccentric out" if you tried.

It has been known that there are bearings made that are sold as direct replacements where the eccentric tightens in the wrong direction.

Your correct that the proper tightening direction should be turning the eccentric clockwise. If tightened counter-clockwise, the bearing race would want to run out from under the eccentric and loosen.

[DoubleO7]

Originally Posted by TheSaturnV

Right before I gave up last night, I ignored the gauge tool and set the "finger bolts" much looser. FINALLY the clutch will spin with the lever pulled back. But it can't be right, the 3 fingers are loose in this position and the PTO is nowhere near the gauge setting.

Doing a search on this site I found it mentioned that some PTO's on some tractors just do not work if adjusted per the gauge. And they were advised to adjust it to suit while on the crank and when they did, all was well.

If the center button has the slot a bit off from IH specs, or is a bit different in height that will throw off the gauge adjustment also.

[TheSaturnV]

Ok, that works for my situation/bearing. Counterclockwise seems to bite much better on the crankshaft.

[OffTime]

Originally Posted by DoubleO7

It has been known that there are bearings made that are sold as direct replacements where the eccentric tightens in the wrong direction.

Bearing eccentrics are always round, just off centered. They tighten equally right or left. The direction of rotation that the collar is locked always depends on the direction of rotation of the shaft, or if the shaft is stationary, and the bearing rotates around the shaft, it would depend on the direction of rotation of bearing around shaft. If shaft rotates, lock in same direction as rotation of shaft. If bearing rotates around shaft, lock in opposite direction of rotation of bearing.

[mike melillo]

Originally Posted by OffTime

The service manual is correct.

I don't agree

As long as the bearing spins freely, you may never notice any difference.

I agree

However, the purpose of the lock collar is to lock the bearing to the shaft.

I agree

If the lock collar was to be locked opposite the rotation of the crankshaft, being that the set screws lock the collar to the shaft, any movement in direction of normal rotation would unlock the collar from the bearing. Lock collar must be locked counterclockwise or in same direction as rotation of the crankshaft

I dont agree. I think your saying opposing things. First, I’m not saying the set screw should be binding the coupling of the collar. The collar binds the bearing to the shaft, and the set screw keeps the collar from moving. However the direction you wind up the collar should oppose the direction of rotation, not be tightened with the direction of rotation. Locking in the direction of rotation may result in unlocking the collar. But with that said it also still requires the set screw to come loose, be galled across the bearing, and or something else to fail (like the bearing going bad as you indicated.

In reality, I have locked these both ways and never had any problem, for that very reason. But the most redundant way is to lock the collar in the opposite direction of the crank rotation, which in this case is clockwise. My self doubt was because there is always another way to see a situation.

After more than 30 years of being a mechanic I can tell you that you need to think open-mindedly about mechanical problems because there are often a lot of ways you can view the situation. Being willing to allow yourself to be wrong is far more valuable then always thinking your way of thinking is absolute.

Philosophy aside, I still make stupid mistakes from time to time.


I have attached an image of the late model bearings (direct from Cub Cadet) showing the clip, and groove.

Mike

[tonka.scout800a]

Here's a couple pics of my new bearing if it helps anyone. Haven't had a chance to remove the old one yet.

Stens 225-217 Bearing With Collar Cub Cadet IH-60071-C92

[sawdustdad]

On the locking collar issue, I believe the manual is correct (imagine that). Lock the collar counterclockwise standing in front of the engine facing the PTO. This is necessary because resistance to the engine's rotation (caused by a load on the belt) creates a clockwise torque, effectively tightening the collar.

All of the PTOs I've removed save one were properly installed, one had to be loosened counter clockwise but most had to be untightened clockwise. To be honest, it's all a little theoretical because if the collar is tightened robustly with a punch and a hammer, it's unlikely to loosen either way.

[mike melillo]

[QUOTE=sawdustdad;260619]On the locking collar issue, I believe the manual is correct (imagine that). Lock the collar counterclockwise standing in front of the engine facing the PTO. This is necessary because resistance to the engine's rotation (caused by a load on the belt) creates a clockwise torque, effectively tightening the collar.

I thought of that, but I figured that if the bearing is freely rolling, then there won't be any rotational connection from the pulley to the bearing collar at all. The bearing is simply there to allow free wheeling while disengaged. When the PTO is engaged the bearing really only helps keep the pulley hub on center. There is no transfer of torque through the bearing when functioning properly. When the bearing fails through seizure, then there are other symptoms that are seen before things get dangerous.

Wouldn't you agree?
Mike