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Electric PTO install questions Simplicity 7112 and 3415


Jjsmachines

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Greetings from a newcomer.  I am just starting out on figuring out putting Electric PTO clutch(s) on a Simplicity 7112, six speed with a Kohler 12 HP k301S engine, that has a 3.5 inch long shaft that is 1 inch OD.  I am also looking to do the same to a Simplicity 3415 H with a 15 HP Briggs that has a 4 inch shaft, 1 inch spacer, and 1 in OD.  From researching previous threads here, I found the Warner PTO 5215-142 that fits a 1 inch OD shaft and see that it was installed on a 16 HP Briggs with a spacer. I have a few questions that I hope you all can help with.

1) Clearance - took the hood off and there isn't enough room in the front to get the clutch on either of the engines due to the front of the frame..  How did you overcome that?  Unbolt the engine and raise it?  Will the drive shaft have to be disconnected? Other options?

2) Spacer - the Briggs has a 1" spacer built in on it's front shaft - was that sufficient for the position of the pulley on the Warner 5215-142 to drive the snowblower? Should I use a 1/2" long spacer on the 7112 with the Kohler as the shaft is 1/2" shorter than the Briggs?

3) Wiring - I've seen hints of using a relay or just using an on/off switch?  How have you wired the clutch?

4) Anti rotation pin/clip - how can I source these?  Do I just use a bolt?  Should it have some play?  I saw the picture of the one on the 16 HP Briggs, but it wasn't clear to me where and how it was secured to the engine.

5) Center bolt and washer - I see recommendations to use a minimum of a grade 5 bolt with thread lock and torque it (I forget the foot pounds at the moment). For the washer, do I just use a flat washer that is large enough to cover the inner race of the bearing of the PTO (I hope I am saying that correctly)? Should it be a different type of washer?  The threads in both shafts appear to be fine threads, does anyone know the sizes?

I apologize for so many questions.

Thank you all very much for your help and consideration.

Regards,

Jonathan Ellis, aka Jjsmachines

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Jonathan,

First, welcome to the club.

You were probably reading my posts.  I'm glad someone's making use of them.  

As to an electric front clutch, my understanding started when the "old style" front electric clutch failed on my AC built Homelite T-12.  Most of my installation knowledge came from the parts IPL for the T-12:

image.png.3597e8f59f03a6f46c72d49287f724ea.png

Parts 1,2,&3 are what I used to secure the clutch to the shaft; I don't remember using a grade 5 bolt. Also a square parallel key is used as listed in the part description, not a woodruff key as diagramed

1)  I installed the electric clutch on the 16HP Briggs before I installed it (17GTH-L repower).  However, I've since removed the clutch and I think I had to raise the engine to do it.  I would have unbolted the engine from the fame and most likely removed the fiber disk at the BGB end of the driveshaft to be sure I didn't damage the disk (no need to remove the BGB yoke, just position the end of the driveshaft flange 90deg from the yoke so that they don't interfere).  There might be enough flexibility in the disk such that removing it is your call.  

2) The purpose of the spacer shown above (part 4) is to allow the clutch to be pressed against the step in the shaft.  One wasn't required for my "new style" electric clutch install on the Briggs since the outside face of the inner race of the clutch bearing was past the end of the shaft.  Having a gap allows the clutch to be clamped between the washer and engine shaft step. 

I don't think you will need a spacer, but if you do, you can make one.  I had to make a replacement spacer T-12 since the original had fallen off.  I believe I used schedule 40 1" pipe cut about a 1/4" longer than the end of the engine shaft when the clutch assembly was pushed against the shaft step.  If you make one, make sure the ends are square.  

You state the 3415H has a 1" spacer.  Normally there isn't any spacer on the engine shaft.  I'm thinking at some point your 3415H had a front mechanical PTO installed on it:

image.png.5e83bff3c74fa3df9806b23c4c9e1b1b.png

I'm thinking part  H in the above IPL.

You don't want that spacer on the shaft since it changes the location of the clutch drive pulley.  It pushes it forward.  I selected the 5215-142 clutch since it closely matched the the distance from the shaft step to the pulley groove of the T-12 clutch.  Keeping this distance the same keeps the alignment between the clutch pulley and the mule drive pulleys. 

Most likely that spacer is pretty well rusted to the shaft and that's why it wasn't removed when the mechanical PTO was removed.  It can be a bear to remove, I know from experience.  Since you don't need it you can always cut it off or see how much it effects the belt alignment with it on.  

Hopefully, the step on the Kohler engine shaft is in about the same place as the Briggs so there are no belt alignment issues.  You want the belt from the clutch pulley to drop straight down into the groove of the mule drive pulleys, basically 90deg.  

3) More later

4) I made the anti rotation bracket from a piece of lightweight aluminum angle I had on hand.  In my experience it doesn't have to be heavy duty, not much force is needed as long as the bearing are good.  When I removed the clutch, I took some better pics since I've been asked about the bracket several times:

 Electric_Clutch_Finger01a.JPG.e3598f674c92be7484cc68fd8c07800c.JPG

I used a thick washer I had on hand to raise the surface of the block bolt hole to be about flush with the face of the cover (I think I had to cut the edge of the washer to fit the cover curve). I put a piece of tygon tubing over the "finger" to prevent metal to metal contact.  

5) Mostly answered above.   The washer should be heavy enough (or double up) to prevent it from bending.  The washer OD is the same as or slightly smaller than the inner race OD.  

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3) I didn’t want the engine to start if the electric clutch was engaged for safety.  

I didn’t use a relay when I wired the electric clutch.  I used a double pole, double throw switch with the "start" circuit connected to one set of the normally closed contacts and the PTO +12V feed wire to the other set of normally open contacts.  

If the PTO switch is “on”, it acts just as the other safeties (trans in neutral, etc) do, the current flow to the engine start solenoid is interrupted and the engine won’t turn over.  If wired this way, beware that the electric clutch will be engaged whenever the switch is on.  

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Hi Bill,

Yes I was reading your posts!  Thank you so much for your answers.  They have shed a lot of light on the situation.  Forgive me, but I have some follow up questions on your answers.

1) Clearance - BGB?, Fiber Disk? - I haven't dug into the machine that far yet and honestly don't know what these are.

2) Spacer - Ok on this I think I used the wrong terminology.  On the Briggs there is a built in "STEP" as was on your 16 HP, not a spacer.  There is no step on the Kohler so I was asking if I should install a spacer on the shaft between the block and the PTO clutch to act as a step - if that makes sense?  Eventually I would like to get the original mechanical PTO as well but hard to find.

3) Got it, thank you

4) Thank you for the additional picture and information - very helpful

5) I think I've got this one too - thank you for the info.

Thank you very much for your help,

Jonathan

 

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1)  There's a bevel gear box (BGB) in the middle of the tractor that changes shaft rotation 90deg.  On the right end of the BGB cross shaft there's a pulley that drives the tranny; on the other end, the cone clutch.  The BGB case is also the structural component that connects the front frame of the tractor to the rear sideplates that hold the tranny.  Some pics of a used one from eBay:

pic1.thumb.jpg.c2d0e53ed72d27b1329e0559cbcebe91.jpg

pic5.thumb.jpg.49edc3502ec1ff50858743c930c00a15.jpg

 

There's a fiberglass disk that acts as a universal joint that handles minor misalignment in the drive train.  On the 3415 there's one at the engine end of the driveshaft also.  On the 7112, rather than the disk, there might be a rubber coupling rather than the simple disk.  A pic of the rear one (75th Ann tractor, same as 7112):

IMG_5548b.JPG.70f0f426077367386bc252ebe32132a8.JPG

In the pic you can see the flange of the driveshaft.  On the other side of the disk is the yoke which connects to the BGB input shaft.  This is the disk I suggest you remove if there's not enough flexibility to lift the engine far enough to get clutch on the engine shaft. 

A pic of the engine end of the driveshaft with a rubber coupling:

IMG_5572.thumb.jpg.c20cc3558ddfb05b41f5441e5ded6123.jpg

In the above pic, the driveshaft flange to rubber coupling is unbolted and you can see the long nose of the driveshaft that extends into the rubber coupling. 

If your setup doesn't have a rubber coupling, and there's not enough flexibility to tilt the engine to get the clutch on, you could also disconnect the front driveshaft flange from the disk.  IMO, there's not a "right way", just what works for you. 

If you do disconnect the driveshaft, it's a good idea to support the driveshaft from dropping and stressing the disk at the other end of the driveshaft.    

 

2)  I didn't realize the Kohler single cylinder engines didn't have a "step" on the engine shaft.  Almost all of the tractors that I've worked on have had Briggs single cylinder engines or Kohler twins.  

So you will need a spacer to have the electric clutch mounted forward for belt alignment and probably to prevent clutch block interference.  I'd think a spacer that positions the front of the spacer at the same distance as the Briggs "step" is from the face of the engine block would be a good starting point.  Measure to confirm. 

 

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Thank you to Bill C. for the links!

Thank you to Bill (PhanDad) for the explanations and pictures.  I've had several "ah-ha!" moments and the light bulb in my head has gone off so many times now.  I just wish the weather was a bit warmer so I can work on the machines in the barn!

Regards,

Jonathan

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Hi all,

Progress!  Engine is up and resting on some boards on the frame.  I ended up disconnecting the driveshaft at the front coupling.  Once the engine mounting bolts were out, I had limited movement and couldn't get the coupling and shaft to separate, but my plan was to use shims under to maneuver the engine to clear the exhaust, and oil drain (drained the oil too).  Once that was done, I used the chain fall to gently lift a little so I could separate the shaft and engine.  The shaft was supported by a cross member so that was all set.  My main reason for going this route is I have the electric lift cylinder up under and I would have to take that out again and was hoping to avoid that.  It might bite me when I go to put it back together, but I will cross that road when I come to it.  Here are some pictures (I hope). This is the 7112 six speed w/Kholer 301.

Jonathan

 

IMG_20201202_141804.jpg

IMG_20201202_141814.jpg

Edited by Jjsmachines
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Hi,

Making more progress but have a question for anyone with a kohler engine (I have a K301 12 HP Horizontal shaft).  What size bolt fits into the front horizontal shaft?  All the manuals I have say 3/8, some with 16 thread and some with 24 thread.  Well that's too small.  The inside of the shaft is fine thread.  I have a 7/16-20 that will start by hand but stops right away.  I haven't tried any lubricant yet.  Could it be a size in between, or metric?  I wouldn't think metric but IDK.

Signed "Too cautious newbie" :)

Jjsmachine

Thanks,

Jonathan 

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From the front mechanical PTO install instructions:

image.png.dc28638e441709e2d2193a3d33a1f325.png

I'm thinking you have some rust inside the hole; run a 7/16-20 tap in the hole to clean out the rust.  

 

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Thank you so much for the diagram and information!  The ones I have do not list the differences for the Briggs and Kohler. I will clean out the threads and see what happens.

Jonathan

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  • 2 weeks later...

I ran a 7/16-20 tap with cutting oil in mainly by hand and it took multiple passes and a lot of rust was removed.  Bolt goes in nice and smooth now.  Unfortunately cold weather has slowed the project down considerably.  Currently have to overhaul the carb on my snowblower.  Now why didn't I do that over the summer???  Out of sight, out of mind.  I knew it had to be done but......... :D

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Well we were pushing 40 degrees today so I went and fiddled in the barn with the electric PTO project.  Based on where the belt comes up and the position of the pulley on the electric PTO, it looks like the unit will have to be as close to the engine as possible without a step/spacer (although I would like to put some machine bushings in just so it isn't right against the block).  I did some trial runs lowering the engine back in and I'm going to have to lower it in at an angle to get the drive shaft back on and an extra set of hands as well to position it all.  I have a 90 degree fitting off the oil drain that might have to come off as well, but I'm not sure if I would be able to get it back on again, once the engine is back in place, if I do take it off.

So now the questions- I'm thinking of putting a light coating of never seize on the shaft when I do the final install - thoughts, suggestions, yay or nay?

Hope everyone has a healthy, safe and wonderful holidays and New Years.

Thanks,

Jonathan

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2 hours ago, Jjsmachines said:

Based on where the belt comes up and the position of the pulley on the electric PTO, it looks like the unit will have to be as close to the engine as possible without a step/spacer

I'm surprised you don't need a spacer to "move" the shaft "step" out away from the block.  This is a pic of a K301 short block (maybe your engine is different):

pic3a.jpg.835a1f4080063df456b020e17534a969.jpg

You stated previously, compared to the Briggs, there isn't a "step", but there's a larger diameter "step" basically even with the block face.  

This is a cross section dwg of the Warner 5215-142 electric Clutch:

I-5215-142_-_B(1in)_Xsect.JPG.ed9a21081636f069eeee29355cc03a3c.JPG

As I read the above dwg, if the "step" was about 0.4" from the block face (0.276" + about another 1/8" (assuming the dwg is to scale), the clutch would just touch the block face.  Add 1/8" for clearance and the "step" should be a bit more than 1/2" from the block face.  These dimensions are to mount the clutch on a Briggs like small diameter "step".  I don't believe the Briggs "step" contacts the the bearing inner race, but sleeve the bearing on:

IMG_9732a.JPG.0535d00190c74b31859a7cb159af4c42.JPG

 

When you installed the clutch, maybe the inner race is resting against the shaft "step"?  (I'm thinking the large diameter "step" won't fit inside the inner race)  Or if the keyway on your shaft is similar to the one pictured, maybe the clutch internal key is bottoming out on the rounded keyway cut before the inner race makes contact?  You suggest using machine bushings.  I'd definitely be adding something to the shaft to make sure the clutch is against a "step" all the way around the shaft.  

Hope this makes some sense.  An interesting setup.  

As to the anti-seize, I think it would be ok - but I'm far from an authority on the subject.  I would think the lock washer will keep the bolt tight.  But I'd keep an eye on it for awhile.  

 

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  • 2 weeks later...

Hi all - I hope everyone is healthy and had good holidays.  Minor update here.  Thank you Bill for your help.  I've only done a mock run on the installation to see how the belt would run to the mule drive attached to the front of the tractor and that is why I was saying that it looked as if the electric PTO/clutch would have to be installed as close to the block as possible as the belt will not be 90 degrees down, even if I put the PTO/clutch all the way in.  The end of the keyway would prevent it being flush to the block just as in the picture you show of a K301, which is spot on and my engine is the same.  I agree definitely on adding something to the shaft to make sure the clutch is against a "step" all the way around.  The conundrum is what to use and how thick/long.  I can't find any large and beefy enough machine bushings locally.  The ones I did find were measly 14 gauge and fit the shaft but are not large enough on the outer diameter to help.  I do have one machine bushing that I found in the barn that will work.  I just feel I need 2 or 3 more to "step" the PTO/clutch effectively away enough.  I've done some searching on McMaster-Carr and found a few things that I think would work - but they are a bit pricey, especially after the shipping.  I played around with a piece of black pipe to try and make something but couldn't get the cut completely flat/flush - level/90 degrees even with filing and grinding, so I abandoned that idea as I felt it would not be a good plan for wear on the bearings.  As for the never seize, I was planning on putting it on the shaft to prevent the PTO/clutch from rusting to the shaft.

Thanks,

Jonathan

Edited by Jjsmachines
typos
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I had a neighbor who owned a welding/metal fab business cut me a spacer once.  He had what I'd call a vertical pivot band saw (like a chop saw) that made square cuts.  The 1" spacer was made from 1" schd 40 pipe which has an OD a bit larger that 1" and an OD of 1.3. 

4 hours ago, Jjsmachines said:

Grainger has the same and you'd only have to buy 25:

https://www.grainger.com/product/GRAINGER-APPROVED-Machinery-Bushing-5MXD2

 

 

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Well I got the bushings from Granger (thank you Bill!) and I've done a dry run install with 2 bushings on the shaft and it seems that that will do the trick.  I made a crude anti-rotation bracket out of some angle metal, tapped out the rust in the hole I needed for that, cut down a 3/8-16 bolt to fit and ran a die and file on the end to clean it up and did a dry run install of the parts again.  Tomorrow I will paint the anti-rotation bracket and then get some rubber over the tab like Bill did.  Then once all that is installed, I just have to get a switch, wire it up and then put everything back together.  All of this is weather dependent of course!  I am attaching some pictures too.  Thanks again for all the help - its starting to get there!  If the pictures stay in order, the first one is the clearance with 2 bushings, the second is the PTO/clutch in place, and the third shows the crude anti-rotation bracket in place - not painted or with rubber on the tab yet.

Jonathan

IMG_20210113_144157.jpg

IMG_20210113_173341.jpg

IMG_20210113_173334.jpg

Edited by Jjsmachines
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  • 2 weeks later...

Thanks everyone!

Update - more progress as I have dropped the engine back into the frame and re-connected the drive shaft.  The 2 inch bolt wasn't threaded all the way  and wouldn't go in far enough, so I ran a 7/16-20 die on it with cutting oil very slowly and carefully (grade 5) and it worked like a charm.  I also picked up a manual engagement PTO, but made the mistake of NOT checking all the details 1st as it came off an engine with an inch and and 1/8 shaft and my 3415 has a one inch OD so, oops!  Back to square 74 or whatever :D

Pictures:

IMG_20210121_171413.jpg

IMG_20210126_145522.jpg

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