1811 possible mule drive pulley seized ruining crankshaft seal?

[Eslenk]

Originally Posted by Ambush

People with a lot of experience are telling you that the pulley and seal leaking are unrelated and I strongly agree. Actually I’ll go further and say just plain “nope”.

You said you’ve changed the seal numerous times over your time with the tractor. You have a shaft problem in that case. Many of those crank seals last twenty years and more. I’ve changed literally many thousands of seals in my career. Repeated premature failure always has a cause. Find the cause. And it’s not your pullleys.

I've changed the seals several times over the years because the engine was removed to clean the grass build-up on the heads,etc, not because the seals were leaking but because it was already apart.

There is no repeated premature failure just preventive maintenance.


The engine drives a belt that turns the pulleys.
If the pulleys offer resistance to the point of seizing and stopping the engine, will the engine run hotter or cooler?
If the answer is it will run hotter the next question is, is it possible it got hot enough to cause seal damage?

[Ambush]

No. If the engine got hot enough to cook that seal, then you’d have engine damage.

[CubDieselFan]

The engine will not care if that pulley seized. It would just smoke the belt until it broke.

[Eslenk]

Originally Posted by CubDieselFan

The engine will not care if that pulley seized. It would just smoke the belt until it broke.

Wrong.
My engine bogged down, let out a quick burst of smoke from the front and engine shut down.

Turned off PTO, started engine and drove it on the trailer.

Belt is still intact.

[CubDieselFan]

Originally Posted by Eslenk

Wrong.
My engine bogged down, let out a quick burst of smoke from the front and engine shut down.

Turned off PTO, started engine and drove it on the trailer.

Belt is still intact.

You are correct, I remember reading that now. What part are Ga are you in? We are in Commerce tonight. Picking up a new project tomorrow.

[SS5150]

I still can't see how this is related. So the pulley seized and stalled the engine, which would be a relatively quick event? Or was it (over)loading the engine for an extended period? I'd have to think if that was the case you'd notice something was wrong and shut it down yourself.

If it went as your speculating I think you'd have other problems too. I'd think the engine oil would be badly burnt/overheated.

I'm thinking a) seal lip got cut/folded over on install, b) wrong seal, c) as previously mentioned an aged, hardened seal; d) groove in the crank surface.

I'm still surprised it didn't overpower the seized pulley and burn the belt. Could you hear the bearing growling on the mule pulley? It would almost have to be loud, and probably created a tremendous amount of heat as it failed.

[Eslenk]

Originally Posted by SS5150

I still can't see how this is related. So the pulley seized and stalled the engine, which would be a relatively quick event? Or was it (over)loading the engine for an extended period? I'd have to think if that was the case you'd notice something was wrong and shut it down yourself.

If it went as your speculating I think you'd have other problems too. I'd think the engine oil would be badly burnt/overheated.

I'm thinking a) seal lip got cut/folded over on install, b) wrong seal, c) as previously mentioned an aged, hardened seal; d) groove in the crank surface.

I'm still surprised it didn't overpower the seized pulley and burn the belt. Could you hear the bearing growling on the mule pulley? It would almost have to be loud, and probably created a tremendous amount of heat as it failed.

I would say the pulley was progressively overloading the engine over time until it eventually seized.
I base that on the condition of the other mule drive pulley that did not seize.
For example, the pulley that did not seize I can turn the pulley by hand but I can not spin it freely.

The new pulleys that I bought I can spin them and they will spin freely several revolutions before they come to a stop.

I didn't hear any sudden growling but I'm sure when the pulleys start to fail over time you don't notice the difference in sound.

A bearing/pulley doesn't go from "brand new condition" to seizing in one use, these mule drive pulleys have been on the mower since I bought it used (20+ years ago and may never have been changed.

I ran the engine after replacing the seal to check for leaks with the blades NOT engaged and did not see any leaks or run hot.

As I was finishing cutting the grass this happened.
When I checked the oil level the level was barely, if at all low on the dipstick which leads me to believe the oil leak was not caused by a damaged seal on install because I believe more oil would have leaked out during the amount of time I was cutting the grass.

[SS5150]

I'm still struggling with the correlation of the two issues.

Regardless, another thing I thought of later, is a member on another board put an M20 crank seal into his M18 by mistake. The inner diameter is slightly different. In his case he grabbed the wrong part by accident. I'm wondering if you maybe got a mispackaged seal. I believe his situation was similar, mowed his lawn and then rechecked later and had an oil drip.

[ironman]

Multiple replies to your question, including my own, have stated that they don't believe your theory of an engine overheated by sluggish mule drive pulleys ruined a brand new crank seal.
Yet you have convinced yourself that you are correct and refute anyone who differs with you.

So I'll throw another theory at you to refute.....
You say in your opening post that the oil that exited the motor made a "BIG mess", and yet multiple times you said the oil level in the motor was "barely low, if at all".

How can that be? Just maybe you overfilled the oil to begin with.
Too much oil, too much crankcase pressure, extra oil gotta go somewhere.

But that makes no sense because you have a seized mule pulley.

[ol'George]

Originally Posted by Eslenk

I would say the pulley was progressively overloading the engine over time until it eventually seized.
I base that on the condition of the other mule drive pulley that did not seize.
For example, the pulley that did not seize I can turn the pulley by hand but I can not spin it freely.

The new pulleys that I bought I can spin them and they will spin freely several revolutions before they come to a stop.

I didn't hear any sudden growling but I'm sure when the pulleys start to fail over time you don't notice the difference in sound.

A bearing/pulley doesn't go from "brand new condition" to seizing in one use, these mule drive pulleys have been on the mower since I bought it used (20+ years ago and may never have been changed.

I ran the engine after replacing the seal to check for leaks with the blades NOT engaged and did not see any leaks or run hot.

As I was finishing cutting the grass this happened.
When I checked the oil level the level was barely, if at all low on the dipstick which leads me to believe the oil leak was not caused by a damaged seal on install because I believe more oil would have leaked out during the amount of time I was cutting the grass.

A new idler pulley that has enough lube to last a lifetime, will have lube of the consistancy to allow it to turn freely, but not spin several turns,---- 1/2 turn usually,--at room temp.
Some pulleys are rebuildable if they have a separate ball bearing, instead of the cheap ones that have the actual pulley stamping as the outer race,
the riveted ones can be drilled out and new bearings put in and the pulley halves are then bolted back together using Allen bolts /nuts.
But usually, the pulleys "V" has worn into a "U" shaped groove where the belt rides, and that condition causes premature belt wear,and should not be reused.
Next time you mow -or anyone,
stop the mower and quickly touch the belt, but caution ,as it is very hot!!
The heat is generated by the 1/4 turns and bending around pulleys, also look at the PTO pulley,
you will notice the "V" groove is most always very worn and looking like a "U" not a vee.
just some info into belt life.