MEP-531 and MEP-501 removing couplers

[rustystud]

Does anyone know how to remove the drive coupler off the engine shaft ? This is the one that has a flexible coupling between the alternator and engine. I've tried a puller and slide hammer and nothing budges this thing ! I of course removed the two set screws and still nothing. It looks like the coupler rides on a bushing of some kind and this bushing is pressed on the main shaft.
I'm also trying to remove the armature from my MEP-531 . I have the stator off but it looks like there is just one bolt holding the rotor on. Any ideas ?

 

[Guyfang]

I have never removed the drive coupler myself, but one of my brits did. He said it was "glued on" and used a hair dryer to warm it up, carefully using a rubber hammer to tap on it and then pulled it off with a slide hammer. I used many words that we can not print here, to describe the operation.

I took a look at the exploded diagrams in the manuals and it appears that everything is pressed on. For both sets. So I can only guess, heat, heat and more heat, with some tapping to help loosen it up.

 

[rustystud]

I have never removed the drive coupler myself, but one of my brits did. He said it was "glued on" and used a hair dryer to warm it up, carefully using a rubber hammer to tap on it and then pulled it off with a slide hammer. I used many words that we can not print here, to describe the operation.

I took a look at the exploded diagrams in the manuals and it appears that everything is pressed on. For both sets. So I can only guess, heat, heat and more heat, with some tapping to help loosen it up.

Thanks for the information. I just hate using heat on engine shafts. I think your right though. They must have used some sort of gear or shaft Loctite to keep that bushing on tight ! I guess I'll have to use some heat to get the adhesive to loosen up.
I recently bought this MEP-531. It had a bad injection pump but the generator was fine. Just so happens I bought 2 brand new MEP-501 units a year ago. So I figured I would swap out the generator and install it on my new engine on the MEP-501. I guessed when they assembled these units they never figured anyone would ever need to remove the coupler from the shaft. If it was that far gone then the military would just get a new one. I will say these Yanmar engines are the smoothest running little diesels I have ever come across ! Now if I can find another MEP-531 with a bad engine I can convert the other MEP-501 to a 2KW generator. I have never come across a need for the 28 volt DC unit though I think the alternator could be adapted to fit the deuce. That would give you a 71 amp alternator in the small size (like a Delco 12 volt) instead of the monster unit it has now.

 

[Guyfang]

Rusty,

I just looked up the work package related to removal, test, and replacement of the main gens. Yes, a step in the reassembly portion of the manual calls for applying an "adhesive" to the shaft before replacing the adapter/flange. I should have looked the first time. But, like that old country song says, "Old and In the Way". The adhesive is listed in the Expendables section of the manual.

We used the 28 volt DC gen set a lot. We wanted to use the radios, and other gear in the vehicles, without running the vehicle engines.

Yep, the yanmar makes some fine engines. Smooth as silk. Simple, easy to work on.

 

[rustystud]

Well I had to heat it up. Here are the tools needed to remove it after heating it. The bolt I used I drilled a small hole to set the puller into so I didn't damage the crank end. I used the pry bar to keep the puller from turning the crank. When it finally came off I thought I had broken my puller ! It shot out about 2 feet ! All that work for that little bushing. Who would have thought it !
I will not be using any adhesive on it when I put everything back together ! In fact I think I will be using some "anti-sieze" .

 

[Guyfang]

The same thing happened to me with a pully on an old,old 45 KW Stewart and Stevens. When the whole mess flew off, my hand was kinda in the way. The crack of the pulley leaving the shaft was heard around the world. My hand hurt for several days. Since then, I try and "tap" whatever I am removing, with a large sand filled hammer after heating. When I say "tap", I mean something less then whaling the heck out of it, and more than playing the drums. I screw in a short bolt and flat washer. Protects the shaft, if I am off a tad. Beat it 2-3 times and then on with the puller. Sometimes it helps. Sometimes not!

Nice tools. Snap On. A cheap pulley puller is destined to fail.

 

[rustystud]

The same thing happened to me with a pully on an old,old 45 KW Stewart and Stevens. When the whole mess flew off, my hand was kinda in the way. The crack of the pulley leaving the shaft was heard around the world. My hand hurt for several days. Since then, I try and "tap" whatever I am removing, with a large sand filled hammer after heating. When I say "tap", I mean something less then whaling the heck out of it, and more than playing the drums. I screw in a short bolt and flat washer. Protects the shaft, if I am off a tad. Beat it 2-3 times and then on with the puller. Sometimes it helps. Sometimes not!

Nice tools. Snap On. A cheap pulley puller is destined to fail.

Most of my tools are Snap-On. I do have some Mac and OTC and other name brands especially my "Specialty" tools, but my main tools have always been Snap-On. I couldn't afford having my tools let me down or hurting me like a bad puller can do. I tried to get in there with a hammer but there is no room with that stupid housing in the way. So it was basically heat it and pull it.

 

[Guyfang]

If you need tools for your job, you need tools that last a lifetime. Cheap tools are a liability. Why buy a tool more then one time? Pay a bit more for a good tool, it's your friend for life. People who buy cheap tools have no respect for them. Screwdrivers become pry bars, scrapers, chisels and so on. A ratchet becomes a hammer. No, not for me. That doesn't mean someone should go out and drop mega bucks on tools. Get what you need. Then you can always buy a little something extra, when you have saved a little gold dust up. Its taken me 20 years and longer to get what I need. AND I do NOT loan tools. But we have been down this road before. Broom handle to the hand for anyone foolish enough to reach into my box.

It must be early, or late, depending how you see it where you are. Cant sleep?

 

[rustystud]

If you need tools for your job, you need tools that last a lifetime. Cheap tools are a liability. Why buy a tool more then one time? Pay a bit more for a good tool, it's your friend for life. People who buy cheap tools have no respect for them. Screwdrivers become pry bars, scrapers, chisels and so on. A ratchet becomes a hammer. No, not for me. That doesn't mean someone should go out and drop mega bucks on tools. Get what you need. Then you can always buy a little something extra, when you have saved a little gold dust up. Its taken me 20 years and longer to get what I need. AND I do NOT loan tools. But we have been down this road before. Broom handle to the hand for anyone foolish enough to reach into my box.

It must be early, or late, depending how you see it where you are. Cant sleep?

My body is pretty messed up. 34 years in the heavy truck repair industry will do that. I've had 32 surgeries to try and repair all the damages. The last one they stuck a rod up my back and "accidently" screwed into my spinal cord. Now I have permanent nerve damage. Of course I had to sign a release form for the doctor to even attempt the surgery so its "so sad, to bad" for me. They do give me interesting pain meds though. I don't like taking them during the day though. I prefer to work hard and also exercise which gives me my own endorphin rush. The problems occur at night when I slow down and watch TV or read. Then when it's time to go to bed I'm playing catch-up on the pain control. I usually take my pills at the same time everyday, but some days when I'm feeling pretty good I forget to take them. Then it hits me like a freight train of pain ! Then I can be up till 4:00am trying to get the pain to subside enough to sleep. Of well, everyone has their problems to deal with.

 

[Guyfang]

Getting old, just ain't what its cracked up to be. I can't go to work without pain killers, and I can't work safely with pain killers. Oh well, retirement is just around the corner.

Sadly, I don't have a camera. It looks like an entire Aviation Company just flew over the house, in the direction of Grafenwoehr Training Area. What an impressive sight!! Had to be the boys from Katterbach. Ansbach is closed now.

 

[rustystud]

Getting old, just ain't what its cracked up to be. I can't go to work without pain killers, and I can't work safely with pain killers. Oh well, retirement is just around the corner.

Sadly, I don't have a camera. It looks like an entire Aviation Company just flew over the house, in the direction of Grafenwoehr Training Area. What an impressive sight!! Had to be the boys from Katterbach. Ansbach is closed now.

Sadly they forced me to retire just this year. I worked with the painkillers for over 10 years no problem. In fact my doctor had to write a letter for me stating that without the painkillers I could not function and that the pain meds allowed me to function normally.
So are you still working for the military over there ? and when you do retire are you planning on staying ?

 

[Guyfang]

I got to germany on the last day of june, 1973. Since then, I have spent 1 year in Ft. Lewis, Washington, 1 year in Ft. Bliss, Texas and 6 months in APG and Ft. Lost in the Woods, Mo. in schools. That's it. I retired from the army in 1993. Went to trade school here and became an electrician. Worked 9 years for a construction company, mostly repairing cranes, generators, lifts, cables and anything else someone wanted fixed. Installed houses also. Then after the company went belly up, (2200) people on the streets) I worked for a *iss poor electrial company installing houses, for 2 years. The boss and I did not see eye to eye. Then started contracting for the military, about 8 years. Contracts ran out and I started working for a slave labour company that rented my body out to anyone who needed an electrician. After you hit the age of 40, here in germany, you are screwed for finding meaningful work that pays half decent. I was 58, so you can guess how nice it was. Then they rented me out to a company that does photoelectric, Biogas Power Plants and transformer repair/replacements. After a week, I noticed a lot of interest in me. Everyone worked a few days with me and then one fine day, the boss called me in, and asked me if I wanted to start with his company. I held up my hand, told him to wait one. Pulled out my cell, called the slave company and told the supervisor that I had good news, and bad news. He asked me what the good news was. I told him I am doing "saugut". Translation, "pig good". It means super good in dialect. So he asked me what the bad news was. I told him I quit as of this very minute and second, and hung up. My new boss stared at me and said, "I guess you want to start work here". Been there ever since. I will be 63 next year and can retire with full benefits on 1 Oct, 2017. We have house and two fine sons here, so I do not think I will go anyplace else. I want to spend some time in the USA, but as just about everyone who is related to me has passed away, I am not sure if I will visit much. Guess we shall see, said the blind man as he picked up his hammer and saw. I still want to work a little. My company has already told me I can do part time work as much as I want. As long as I don't have to do the real heavy work, I can get by with just a little pain killers. But much of the work is simply too heavy for an old fart like me. I am 62, and the next oldest person in the firm is 39, and he is a desk jockey. The other electricians are all about 27 years old. Both of my sons are older. I am the kinda guy that likes to keep up with my co-workers. I have always pulled my weight, and then some. But its just not possible. I am going to miss it badly, when I stop work.

So what do you do to keep out of trouble?

 

[rustystud]

[
So what do you do to keep out of trouble?[/QUOTE]

I work on my deuce and M1028 Chevy and my assorted generators. I also putt around the house and yard (4 acres) . I also love to read and collect books. I have quite an collection now. At last count I had over 10,000 books. That was a few years ago and the collection is bigger now. I have one of the most extensive libraries of Motor Manuals the sales rep ever saw. I have some of the rarest books from 1938 to 1945 . My collection goes to 2010 .In the later years Motor went to two books each year. Plus all the off shoot manuals like Electrical, Wiring and Vacuum diagrams, Driveability, and more. There is also the Truck manuals. I have the very first Truck book in excellent condition. Of course they later sub divided them into Truck and Diesel and then into Heavy and Light duty. I also have all the Motor transmission books both American and Import. I also have quite a few factory repair manuals for transmissions, some extremely rare like the "Double Dual Range Hydromatic" used in the large trucks and my Allison Transmission Manuals. Then there's my military collection. So I'm on a number of book collector sites every night besides being here on Steel Soldiers. My wife said some "blasphemous" words the other day about selling my tools so I could support my book collecting ! She said since I don't work anymore there is no need to keep those tools which I paid over $100,000.00 for . I said "are you kidding me ? sell my tools ?!" . I explained I would only get pennies on the dollar back. I would rather give them away to friends and family before I threw them away to strangers. She then said why not just sell the transmission tools, after all they should bring in good money. I said I just rebuilt my transmission and a few months earlier my friends 4L60E . Why would I sell my transmission tools ? She replied you don't need all of them, are you really going to be rebuilding those new transmissions again ? (she meant the 6L90E) . I replied "you never know" . Then I asked her "are you ever going to use those dinner plates (wedgewood) and silverware (solid silver) you got from your grandmother ? " . She said that's different since they are personal . I replied my tools are personal to me. She walked away after that and hasn't brought up the subject again.
So that is basically what I do now. Argue with my wife !

 

[87Nassaublue]

Thanks for the information. I just hate using heat on engine shafts. I think your right though. They must have used some sort of gear or shaft Loctite to keep that bushing on tight ! I guess I'll have to use some heat to get the adhesive to loosen up.
I recently bought this MEP-531. It had a bad injection pump but the generator was fine. Just so happens I bought 2 brand new MEP-501 units a year ago. So I figured I would swap out the generator and install it on my new engine on the MEP-501. I guessed when they assembled these units they never figured anyone would ever need to remove the coupler from the shaft. If it was that far gone then the military would just get a new one. I will say these Yanmar engines are the smoothest running little diesels I have ever come across ! Now if I can find another MEP-531 with a bad engine I can convert the other MEP-501 to a 2KW generator. I have never come across a need for the 28 volt DC unit though I think the alternator could be adapted to fit the deuce. That would give you a 71 amp alternator in the small size (like a Delco 12 volt) instead of the monster unit it has now.

I think Guyfang hit the nail on the head with this one. I believe you'll need to heat the shaft and/or coupler till it's just hot enough to smoke. I think if I were you, I'd heat the coupler. I'd also use a cutting torch to get it up to temp quick so not too much heat is transferred to the shaft. You're right about the yanmars too. They are much smoother running engines than the onans.

 

[87Nassaublue]

[
So what do you do to keep out of trouble?

I work on my deuce and M1028 Chevy and my assorted generators. I also putt around the house and yard (4 acres) . I also love to read and collect books. I have quite an collection now. At last count I had over 10,000 books. That was a few years ago and the collection is bigger now. I have one of the most extensive libraries of Motor Manuals the sales rep ever saw. I have some of the rarest books from 1938 to 1945 . My collection goes to 2010 .In the later years Motor went to two books each year. Plus all the off shoot manuals like Electrical, Wiring and Vacuum diagrams, Driveability, and more. There is also the Truck manuals. I have the very first Truck book in excellent condition. Of course they later sub divided them into Truck and Diesel and then into Heavy and Light duty. I also have all the Motor transmission books both American and Import. I also have quite a few factory repair manuals for transmissions, some extremely rare like the "Double Dual Range Hydromatic" used in the large trucks and my Allison Transmission Manuals. Then there's my military collection. So I'm on a number of book collector sites every night besides being here on Steel Soldiers. My wife said some "blasphemous" words the other day about selling my tools so I could support my book collecting ! She said since I don't work anymore there is no need to keep those tools which I paid over $100,000.00 for . I said "are you kidding me ? sell my tools ?!" . I explained I would only get pennies on the dollar back. I would rather give them away to friends and family before I threw them away to strangers. She then said why not just sell the transmission tools, after all they should bring in good money. I said I just rebuilt my transmission and a few months earlier my friends 4L60E . Why would I sell my transmission tools ? She replied you don't need all of them, are you really going to be rebuilding those new transmissions again ? (she meant the 6L90E) . I replied "you never know" . Then I asked her "are you ever going to use those dinner plates (wedgewood) and silverware (solid silver) you got from your grandmother ? " . She said that's different since they are personal . I replied my tools are personal to me. She walked away after that and hasn't brought up the subject again.
So that is basically what I do now. Argue with my wife ![/QUOTE]

Hehe, had that argument with my ex-wife! As soon as you sell or get rid of something, you'll have to re-buy it again the next day! I've never sold any tools either, other than junk consumer stuff people gave me. Of course when we got divorced my tools suddenly became worth $1,000,000.

 

[rustystud]

Hehe, had that argument with my ex-wife! As soon as you sell or get rid of something, you'll have to re-buy it again the next day! I've never sold any tools either, other than junk consumer stuff people gave me. Of course when we got divorced my tools suddenly became worth $1,000,000. [/QUOTE]

I've been through that divorce rodeo myself, not fun !

 

[rustystud]

I think Guyfang hit the nail on the head with this one. I believe you'll need to heat the shaft and/or coupler till it's just hot enough to smoke. I think if I were you, I'd heat the coupler. I'd also use a cutting torch to get it up to temp quick so not too much heat is transferred to the shaft. You're right about the yanmars too. They are much smoother running engines than the onans.

I already got the generator up and running. Yes it took heat to get that bushing off ! Like I said earlier when it came off it flew about three feet straight out ! I at first thought the puller had broke !

 

[Guyfang]

I work on my deuce and M1028 Chevy and my assorted generators. I also putt around the house and yard (4 acres) . I also love to read and collect books. I have quite an collection now. At last count I had over 10,000 books. That was a few years ago and the collection is bigger now. I have one of the most extensive libraries of Motor Manuals the sales rep ever saw. I have some of the rarest books from 1938 to 1945 . My collection goes to 2010 .In the later years Motor went to two books each year. Plus all the off shoot manuals like Electrical, Wiring and Vacuum diagrams, Driveability, and more. There is also the Truck manuals. I have the very first Truck book in excellent condition. Of course they later sub divided them into Truck and Diesel and then into Heavy and Light duty. I also have all the Motor transmission books both American and Import. I also have quite a few factory repair manuals for transmissions, some extremely rare like the "Double Dual Range Hydromatic" used in the large trucks and my Allison Transmission Manuals. Then there's my military collection. So I'm on a number of book collector sites every night besides being here on Steel Soldiers. My wife said some "blasphemous" words the other day about selling my tools so I could support my book collecting ! She said since I don't work anymore there is no need to keep those tools which I paid over $100,000.00 for . I said "are you kidding me ? sell my tools ?!" . I explained I would only get pennies on the dollar back. I would rather give them away to friends and family before I threw them away to strangers. She then said why not just sell the transmission tools, after all they should bring in good money. I said I just rebuilt my transmission and a few months earlier my friends 4L60E . Why would I sell my transmission tools ? She replied you don't need all of them, are you really going to be rebuilding those new transmissions again ? (she meant the 6L90E) . I replied "you never know" . Then I asked her "are you ever going to use those dinner plates (wedgewood) and silverware (solid silver) you got from your grandmother ? " . She said that's different since they are personal . I replied my tools are personal to me. She walked away after that and hasn't brought up the subject again.
So that is basically what I do now. Argue with my wife !

Hehe, had that argument with my ex-wife! As soon as you sell or get rid of something, you'll have to re-buy it again the next day! I've never sold any tools either, other than junk consumer stuff people gave me. Of course when we got divorced my tools suddenly became worth $1,000,000. [/QUOTE]


Ever heard that old Roger Miller song, "Everything's coming up Rose's"? Worth a read of the text. Ain't it the truth!