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scag tiger cub electric clutch.
#1
S
scagman2
S
scagman2
My 2003 tiger cub clutch bearings are giving out after 850 hours. Don't know why they don't put grease fittings on them, knowing they will go bad. Is it difficult to replace this # 461661 electric clutch? I hear they tend to seize onto the motor shaft.
#2
reynoldston
reynoldston
I have to say clutch bearings isn't something I have ever had problems with. With a price tag of almost 300 dollars for a new clutch I would try to just replace the bearing if it was mine, unless there is damage. I would say a grease fitting on a clutch would be a disaster waiting to happen with over greasing.
#3
B
bertsmobile1
B
bertsmobile1
Exactly the opposite.
The bolts are hard to get at and generally overtightened.
Nothing much holds them on so they either fall right off and land in your face or you give then a yank and they fly off & smack you in the face.
The bolts are hard to get at and generally overtightened.
Nothing much holds them on so they either fall right off and land in your face or you give then a yank and they fly off & smack you in the face.
#4
John R
I agree, A little is good, a lot is better in peoples minds.:biggrin:
John R
I have to say clutch bearings isn't something I have ever had problems with. With a price tag of almost 300 dollars for a new clutch I would try to just replace the bearing if it was mine, unless there is damage. I would say a grease fitting on a clutch would be a disaster waiting to happen with over greasing.
I agree, A little is good, a lot is better in peoples minds.:biggrin:
#5
M
Mad Mackie
M
Mad Mackie
Electric clutch/brakes last just so long. Usually one of the bearings uses up its grease and overheats. One bearing turns all the time that the engine is running, the pulley bearing turns unless the clutch is on.
Replacing these bearings is not recommended due to their precise positioning and the high probability of damaging the clutch parts when both removing and installing the bearings.
These clutches when mounted on a vertical shaft engine are in a nasty environment being under the machine.
As reynoldston has mentioned, an over greasing situation would destroy the clutch.
Before installing a new clutch, cleaning up the crankshaft where the clutch mounts and applying a very slight amount of anti-seize compound to the crankshaft before installing the clutch is recommended, applying the correct torque to the clutch mounting bolt is highly recommended, do not apply anti-seize to this bolt, the torque spec is for a dry torque.
I remove the screen above the flywheel and hold the flywheel nut with a socket and a breaker bar as I torque the clutch bolt to the correct dry torque spec.
Generally easier to do with one side of the machine jacked up and a rear wheel removed.
Replacing these bearings is not recommended due to their precise positioning and the high probability of damaging the clutch parts when both removing and installing the bearings.
These clutches when mounted on a vertical shaft engine are in a nasty environment being under the machine.
As reynoldston has mentioned, an over greasing situation would destroy the clutch.
Before installing a new clutch, cleaning up the crankshaft where the clutch mounts and applying a very slight amount of anti-seize compound to the crankshaft before installing the clutch is recommended, applying the correct torque to the clutch mounting bolt is highly recommended, do not apply anti-seize to this bolt, the torque spec is for a dry torque.
I remove the screen above the flywheel and hold the flywheel nut with a socket and a breaker bar as I torque the clutch bolt to the correct dry torque spec.
Generally easier to do with one side of the machine jacked up and a rear wheel removed.
#6
B
bertsmobile1
B
bertsmobile1
While I would agree on the grease nipple side, there is no earthy reason why they could not be made rebuildable apart from the initial extra cost.
Some of the units fitted to the air con on a lot of vehicles are rebuildable and they have to handle a lot more power and speed variations than the mower units do.
I have a box fill of metal idler pulleys waiting for the off season to be drilled out & have the bearings replaced.
Most simply get bolted back together and I am yet to have one fail in service.
Some of the units fitted to the air con on a lot of vehicles are rebuildable and they have to handle a lot more power and speed variations than the mower units do.
I have a box fill of metal idler pulleys waiting for the off season to be drilled out & have the bearings replaced.
Most simply get bolted back together and I am yet to have one fail in service.
#7
reynoldston
Never had one in my shop that the bearing went bad in yet but always a first time. As I said I sure would give it a try to replace the bearing if it was mine with the different between a 20 dollar bearing or a 300 dollar clutch. I am not disagreeing or agreeing on the bearing replacement?? Without one of these clutches in my hands in my shop I don't know if they are rebuildable or not. Seeing the old clutch is no good nothing is lost by taking it apart to see if the bearing is replaceable.
reynoldston
While I would agree on the grease nipple side, there is no earthy reason why they could not be made rebuildable apart from the initial extra cost.
Some of the units fitted to the air con on a lot of vehicles are rebuildable and they have to handle a lot more power and speed variations than the mower units do.
I have a box fill of metal idler pulleys waiting for the off season to be drilled out & have the bearings replaced.
Most simply get bolted back together and I am yet to have one fail in service.
Never had one in my shop that the bearing went bad in yet but always a first time. As I said I sure would give it a try to replace the bearing if it was mine with the different between a 20 dollar bearing or a 300 dollar clutch. I am not disagreeing or agreeing on the bearing replacement?? Without one of these clutches in my hands in my shop I don't know if they are rebuildable or not. Seeing the old clutch is no good nothing is lost by taking it apart to see if the bearing is replaceable.
#8
M
Mad Mackie
M
Mad Mackie
Attached are some pics of a Scag P/N 461660 clutch which is found on most Scag Tiger Cub and Tiger Cat machines.
This is my new spare.
This clutch may be repairable, but keep in mind that the keyed sleeve is carefully pressed into both bearings with the electrical coil/brake components already assembled on the sleeve. This will all need to be done on a press using mandrels to support the correct items as they are pressed together, not a job for the average person.
There is a company that is manufacturing replacement clutches with replaceable bearings and they use turned pulleys rather than stamped sheet metal pulleys. As time passes, they are producing more different part numbers of clutches, however not the larger ones such as the Ogura 3.5 GT used on Scag Tiger Cub/Cat.
Notice in the pics that the bearings have different color seals as they are different sizes.
This is my new spare.
This clutch may be repairable, but keep in mind that the keyed sleeve is carefully pressed into both bearings with the electrical coil/brake components already assembled on the sleeve. This will all need to be done on a press using mandrels to support the correct items as they are pressed together, not a job for the average person.
There is a company that is manufacturing replacement clutches with replaceable bearings and they use turned pulleys rather than stamped sheet metal pulleys. As time passes, they are producing more different part numbers of clutches, however not the larger ones such as the Ogura 3.5 GT used on Scag Tiger Cub/Cat.
Notice in the pics that the bearings have different color seals as they are different sizes.
Attachments
#9
John R
John R
Is that center sleve stepped to hold the baring's in place?
Or is there shoulder in the clutch for the bearings?
Or is there shoulder in the clutch for the bearings?
#10
reynoldston
reynoldston
As I said never rebuilt one but in my experience in rebuilding I would think the clutch housing would be stepped. As said a shop press would be handy, but I have installed many bearings with a brass punch and hammer when out of shop. Just be careful you don't pound on the bearing balls.
#11
M
Mad Mackie
Hi John R,
I have no idea as I've never had one of these Ogura clutches apart yet. Several years ago I thought that I was having a clutch problem with my Tiger Cub so I bought a spare. Turns out that I had a ground problem on one of the terminals that are mounted on one of the engine mounting bolts.
I would think that there was at least one shoulder on the center sleeve to facilitate factory assembling, possibly two.
I'll look closer at my spare and check it out. There is an internal snap ring on the pulley bearing which is somewhat promising.
Lower torque clutches stake in the bearings and the stakes need to be ground off in order to both remove and install a new bearing, not easy to do without damaging the stamped sheet metal pulley and housing.
My Ingersoll 4018 garden tractor has a horizontal engine with the clutch on the front of the engine. I remove this clutch periodically, carefully lift the plastic seal and with a needle grease gun adapter, lube the bearings, but this is an easy job to do. This clutch gets overheated from hot engine cooling air and close location to the muffler. I have installed a heat shield on this machine, but I'm not convinced that it does much. I even bought special high temp ball bearing grease for this application.
M
Mad Mackie
Is that center sleve stepped to hold the baring's in place?
Or is there shoulder in the clutch for the bearings?
Hi John R,
I have no idea as I've never had one of these Ogura clutches apart yet. Several years ago I thought that I was having a clutch problem with my Tiger Cub so I bought a spare. Turns out that I had a ground problem on one of the terminals that are mounted on one of the engine mounting bolts.
I would think that there was at least one shoulder on the center sleeve to facilitate factory assembling, possibly two.
I'll look closer at my spare and check it out. There is an internal snap ring on the pulley bearing which is somewhat promising.
Lower torque clutches stake in the bearings and the stakes need to be ground off in order to both remove and install a new bearing, not easy to do without damaging the stamped sheet metal pulley and housing.
My Ingersoll 4018 garden tractor has a horizontal engine with the clutch on the front of the engine. I remove this clutch periodically, carefully lift the plastic seal and with a needle grease gun adapter, lube the bearings, but this is an easy job to do. This clutch gets overheated from hot engine cooling air and close location to the muffler. I have installed a heat shield on this machine, but I'm not convinced that it does much. I even bought special high temp ball bearing grease for this application.
#12
M
Mad Mackie
M
Mad Mackie
Hi again John R and group,
Just looked at my spare Scag clutch, I can't see in at the center sleeve, but I measured the ID of each bearing and the pulley bearing (brown seal) has a smaller ID than the housing bearing (blue seal). This leads me to believe that the sleeve has at least one shoulder and I'll bet that it has two shoulders. This sure would make assembling and reassembling this clutch with new bearings an easy job on a press.
The pulley bearing, brown seal, Japan 34 NACHI 6008NSE
The housing bearing, blue seal, Japan 612 NACHI 6007/37NSE
Just looked at my spare Scag clutch, I can't see in at the center sleeve, but I measured the ID of each bearing and the pulley bearing (brown seal) has a smaller ID than the housing bearing (blue seal). This leads me to believe that the sleeve has at least one shoulder and I'll bet that it has two shoulders. This sure would make assembling and reassembling this clutch with new bearings an easy job on a press.
The pulley bearing, brown seal, Japan 34 NACHI 6008NSE
The housing bearing, blue seal, Japan 612 NACHI 6007/37NSE
#13
B
bertsmobile1
B
bertsmobile1
Must admit, have never looked that closely at the bearings.
I am staggered to find out they are 60 series bearings which are the lightest duty bearings in the metric numbering system.
The second number gets higher as the bearings get stronger.
Thus on domestic ride ons the spindle bearings are generally the 62 series typically 6203, 6205 & 6207
Commercial ride ons generally have heavier duty bearings typically 63's
60's are very light bearings so it is no wonder they collapse .
Working on the Henry Ford principle the bearings would have a working life within 10% of the expceted life of the clutch face & spring.
I am staggered to find out they are 60 series bearings which are the lightest duty bearings in the metric numbering system.
The second number gets higher as the bearings get stronger.
Thus on domestic ride ons the spindle bearings are generally the 62 series typically 6203, 6205 & 6207
Commercial ride ons generally have heavier duty bearings typically 63's
60's are very light bearings so it is no wonder they collapse .
Working on the Henry Ford principle the bearings would have a working life within 10% of the expceted life of the clutch face & spring.
#14
M
Mad Mackie
M
Mad Mackie
I know operators with similar clutches with 3,000 hours on them.
A few years back I repowered an older Scag Turf Tiger for a fellow operator and reinstalled the original clutch as there wasn't anything wrong with it.
Turf Tigers have a horizontal engine and the clutch is easy to replace.
My Tiger Cub has 800 hours on it with no signs of bearing or airgap problems. I turn the PTO on an off at full throttle.
All of my commercial machines have tapered roller bearings in the deck spindles.
A few years back I repowered an older Scag Turf Tiger for a fellow operator and reinstalled the original clutch as there wasn't anything wrong with it.
Turf Tigers have a horizontal engine and the clutch is easy to replace.
My Tiger Cub has 800 hours on it with no signs of bearing or airgap problems. I turn the PTO on an off at full throttle.
All of my commercial machines have tapered roller bearings in the deck spindles.
#15
M
Mad Mackie
M
Mad Mackie
Evidently the bearing "Japan 612 NACHI 6007/37NSE" is a specialized bearing and not available.
This bearing may have a brass bushing of some sort attached to one side which may have something to do with the brake as these clutches are clutch/brakes.
Just my thoughts!!
If and when the clutch on my Tiger Cub fails, I will disassemble it, but this may be a long time away!!!!
This bearing may have a brass bushing of some sort attached to one side which may have something to do with the brake as these clutches are clutch/brakes.
Just my thoughts!!
If and when the clutch on my Tiger Cub fails, I will disassemble it, but this may be a long time away!!!!
#16
S
scagman2
What is the torque spec? Will be installing new clutch soon, spec, not in my operator's manual.
S
scagman2
Electric clutch/brakes last just so long. Usually one of the bearings uses up its grease and overheats. One bearing turns all the time that the engine is running, the pulley bearing turns unless the clutch is on.
Replacing these bearings is not recommended due to their precise positioning and the high probability of damaging the clutch parts when both removing and installing the bearings.
These clutches when mounted on a vertical shaft engine are in a nasty environment being under the machine.
As reynoldston has mentioned, an over greasing situation would destroy the clutch.
Before installing a new clutch, cleaning up the crankshaft where the clutch mounts and applying a very slight amount of anti-seize compound to the crankshaft before installing the clutch is recommended, applying the correct torque to the clutch mounting bolt is highly recommended, do not apply anti-seize to this bolt, the torque spec is for a dry torque.
I remove the screen above the flywheel and hold the flywheel nut with a socket and a breaker bar as I torque the clutch bolt to the correct dry torque spec.
Generally easier to do with one side of the machine jacked up and a rear wheel removed.
What is the torque spec? Will be installing new clutch soon, spec, not in my operator's manual.
#18
S
scagman2
Thanks mechanic mark... great link... ready to install... thanks to all who joined in.
S
scagman2
Thanks mechanic mark... great link... ready to install... thanks to all who joined in.
#19
S
scagman2
Hi M.M. Could you explain in detail the bearing rotation/operation for the ogura 3.5 mco7 clutch? refer to each as upper or lower please. I understand the constant upper rotation, but not the lower... can't wrap my head around that one. Could you please explain?
S
scagman2
Electric clutch/brakes last just so long. Usually one of the bearings uses up its grease and overheats. One bearing turns all the time that the engine is running, the pulley bearing turns unless the clutch is on.
Replacing these bearings is not recommended due to their precise positioning and the high probability of damaging the clutch parts when both removing and installing the bearings.
These clutches when mounted on a vertical shaft engine are in a nasty environment being under the machine.
As reynoldston has mentioned, an over greasing situation would destroy the clutch.
Before installing a new clutch, cleaning up the crankshaft where the clutch mounts and applying a very slight amount of anti-seize compound to the crankshaft before installing the clutch is recommended, applying the correct torque to the clutch mounting bolt is highly recommended, do not apply anti-seize to this bolt, the torque spec is for a dry torque.
I remove the screen above the flywheel and hold the flywheel nut with a socket and a breaker bar as I torque the clutch bolt to the correct dry torque spec.
Generally easier to do with one side of the machine jacked up and a rear wheel removed.
Hi M.M. Could you explain in detail the bearing rotation/operation for the ogura 3.5 mco7 clutch? refer to each as upper or lower please. I understand the constant upper rotation, but not the lower... can't wrap my head around that one. Could you please explain?
#20
M
Mad Mackie
M
Mad Mackie
Hi scagman2,
I am very aware that the engineering drawings of the clutch components are not easy to identify.
Here are the basic requirements of a mower clutch:
Be able to turn a V belt that drives the mower deck with the engine running.
Be able to stop the V belt from driving the mower deck with the engine running.
Provide an "clutch" that will allow the above mentioned to happen.
The clutch being the parts that engage/disengage as desired.
Provide the power/force needed to operate the clutch.
In the Ogura clutch assembly that we have on our Scag Tiger Cubs and many others machines, electricity is the power provided and magnetism is the force.
An electrical coil, when power is applied, provides the magnetic force to operate the parts of the clutch. This coil does not rotate with the crankshaft of the engine.
It is mounted on the lower triangular plate of the clutch assembly which has a bearing pressed into it. The rest of the clutch assembly rotates with the crankshaft with the exception of the deck V belt drive pulley, which also has a bearing installed in it. All of this is mounted onto the sleeve that pushes up against the pump drive pulley and is held in place by a keyway, key and the bolt that threads into the center of the crankshaft.
When the PTO switch is in the on position, power causes the coil to make magnetism which brings the two steel clutch plates together and turns the mower deck.
When the PTO switch is in the off position, the magnetism stops and the clutch plates separate stopping the mower deck from turning.
"Burnishing" of the clutch is when at lower engine RPMs, the clutch is operated intermittently to allow the friction surfaces of the clutch plates to wear into each other gradually so they will not slip during normal mower operation.
The six fingers shown in the Ogura diagrams are what flex when the clutch is engaged and also pull the V belt pulley when the PTO is on.
As these clutches are actually a clutch/brake, when the PTO switch is turned off, the brake engages to stop the clutch quickly. This braking action is adjustable by changing the air gap adjustments. Too small of an airgap will cause the brake to drag, to big of an airgap will cause clutch slippage and slower braking action.
The bottom line to the bearings is that the lower bearing turns all the time that the engine is running.
The pulley bearing turns all the time that the PTO is off and stops turning when the PTO is on as it now turns with the crankshaft.
Time for Mad Mackie to refill his adult beverage container!!!:laughing:
I am very aware that the engineering drawings of the clutch components are not easy to identify.
Here are the basic requirements of a mower clutch:
Be able to turn a V belt that drives the mower deck with the engine running.
Be able to stop the V belt from driving the mower deck with the engine running.
Provide an "clutch" that will allow the above mentioned to happen.
The clutch being the parts that engage/disengage as desired.
Provide the power/force needed to operate the clutch.
In the Ogura clutch assembly that we have on our Scag Tiger Cubs and many others machines, electricity is the power provided and magnetism is the force.
An electrical coil, when power is applied, provides the magnetic force to operate the parts of the clutch. This coil does not rotate with the crankshaft of the engine.
It is mounted on the lower triangular plate of the clutch assembly which has a bearing pressed into it. The rest of the clutch assembly rotates with the crankshaft with the exception of the deck V belt drive pulley, which also has a bearing installed in it. All of this is mounted onto the sleeve that pushes up against the pump drive pulley and is held in place by a keyway, key and the bolt that threads into the center of the crankshaft.
When the PTO switch is in the on position, power causes the coil to make magnetism which brings the two steel clutch plates together and turns the mower deck.
When the PTO switch is in the off position, the magnetism stops and the clutch plates separate stopping the mower deck from turning.
"Burnishing" of the clutch is when at lower engine RPMs, the clutch is operated intermittently to allow the friction surfaces of the clutch plates to wear into each other gradually so they will not slip during normal mower operation.
The six fingers shown in the Ogura diagrams are what flex when the clutch is engaged and also pull the V belt pulley when the PTO is on.
As these clutches are actually a clutch/brake, when the PTO switch is turned off, the brake engages to stop the clutch quickly. This braking action is adjustable by changing the air gap adjustments. Too small of an airgap will cause the brake to drag, to big of an airgap will cause clutch slippage and slower braking action.
The bottom line to the bearings is that the lower bearing turns all the time that the engine is running.
The pulley bearing turns all the time that the PTO is off and stops turning when the PTO is on as it now turns with the crankshaft.
Time for Mad Mackie to refill his adult beverage container!!!:laughing:
#21
S
scagman2
Thanks M.M. for the detailed description. Guess I had it reversed... the upper and lower bearing functions. Odd though that the upper bearings go bad first when the lower bearing is the one in constant use... or have I misunderstood? Check out Xrteme Outdoor Power Equipment. They claim to have cooler bearing operation and longer life... you decide.
Anyway, If I understood your detailed post... the bottom bearing rotate constantly during engine operation, and top bearingdoes also...but stops rotation while clutch/deck is operating... still seems backward as top bearings usually are first to go bad on these units.
S
scagman2
Hi scagman2,
I am very aware that the engineering drawings of the clutch components are not easy to identify.
Here are the basic requirements of a mower clutch:
Be able to turn a V belt that drives the mower deck with the engine running.
Be able to stop the V belt from driving the mower deck with the engine running.
Provide an "clutch" that will allow the above mentioned to happen.
The clutch being the parts that engage/disengage as desired.
Provide the power/force needed to operate the clutch.
In the Ogura clutch assembly that we have on our Scag Tiger Cubs and many others machines, electricity is the power provided and magnetism is the force.
An electrical coil, when power is applied, provides the magnetic force to operate the parts of the clutch. This coil does not rotate with the crankshaft of the engine.
It is mounted on the lower triangular plate of the clutch assembly which has a bearing pressed into it. The rest of the clutch assembly rotates with the crankshaft with the exception of the deck V belt drive pulley, which also has a bearing installed in it. All of this is mounted onto the sleeve that pushes up against the pump drive pulley and is held in place by a keyway, key and the bolt that threads into the center of the crankshaft.
When the PTO switch is in the on position, power causes the coil to make magnetism which brings the two steel clutch plates together and turns the mower deck.
When the PTO switch is in the off position, the magnetism stops and the clutch plates separate stopping the mower deck from turning.
"Burnishing" of the clutch is when at lower engine RPMs, the clutch is operated intermittently to allow the friction surfaces of the clutch plates to wear into each other gradually so they will not slip during normal mower operation.
The six fingers shown in the Ogura diagrams are what flex when the clutch is engaged and also pull the V belt pulley when the PTO is on.
As these clutches are actually a clutch/brake, when the PTO switch is turned off, the brake engages to stop the clutch quickly. This braking action is adjustable by changing the air gap adjustments. Too small of an airgap will cause the brake to drag, to big of an airgap will cause clutch slippage and slower braking action.
The bottom line to the bearings is that the lower bearing turns all the time that the engine is running.
The pulley bearing turns all the time that the PTO is off and stops turning when the PTO is on as it now turns with the crankshaft.
Time for Mad Mackie to refill his adult beverage container!!!:laughing:
Thanks M.M. for the detailed description. Guess I had it reversed... the upper and lower bearing functions. Odd though that the upper bearings go bad first when the lower bearing is the one in constant use... or have I misunderstood? Check out Xrteme Outdoor Power Equipment. They claim to have cooler bearing operation and longer life... you decide.
Anyway, If I understood your detailed post... the bottom bearing rotate constantly during engine operation, and top bearingdoes also...but stops rotation while clutch/deck is operating... still seems backward as top bearings usually are first to go bad on these units.