Stuck with removing flywheel from Yanmar 6LY
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Waterant
Senior Member
yes, i would probably pull that bolt out by now if it was still there and was the only thing holding the pulley.
i think the end has a very small taper and some kind "person" who assembled it is laughing his ass off right now.
i was telling exactly the same to that pulley many times in 2 different languages with a lot of colorful adjectives. maybe it only understands Japanese. I'll try to find a few words to describe my frustration.
OP
OP
Waterant
Senior Member
it seems like the bolt has to go the other way around, so you can use a wrench on it to push against the shaft.
i hope your pulley will not be as stubborn as mine.
RT Firefly
Enigma
luna
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Although some might enjoy the comic relief that Mr. Enigma provides, it is not the way forward.
As your exploded view of the crank pulley showed the bolt/retainer, I just had to ask, forgive me please. I'm just trying to help.
To me no small taper exists, the pulley just slides on, and is driven by the clamping force of the bolt/retainer, just like your alternator pulley, which is likely the largest load.
The question remains, why won't it just pull off?
To me the answer likely lies in whatever is the purpose of the fluted element. This element is interesting not shown on your exploded view. Perhaps you need a different manual.
If it was me, I would contact Yanmar, explain the condition and seek their advice.
This is not the first time a crank pulley has to be removed.
I will stand down now, good luck.
As your exploded view of the crank pulley showed the bolt/retainer, I just had to ask, forgive me please. I'm just trying to help.
To me no small taper exists, the pulley just slides on, and is driven by the clamping force of the bolt/retainer, just like your alternator pulley, which is likely the largest load.
The question remains, why won't it just pull off?
To me the answer likely lies in whatever is the purpose of the fluted element. This element is interesting not shown on your exploded view. Perhaps you need a different manual.
If it was me, I would contact Yanmar, explain the condition and seek their advice.
This is not the first time a crank pulley has to be removed.
I will stand down now, good luck.
OP
OP
Waterant
Senior Member
Thanks for the suggestion. I'll try to find a contact for Yanmar, but they probably will not support a 20-year-old engine. Worth trying anyway.
I just checked again, and that fluted element is a part of the pulley (attached photo)
My best guess is that those holes are there to rotate the pulley/crankshaft for the timing adjustments or something like that.
Checking for the thread was a solid suggestion, and it would explain why that pulley is not cooperating. i would feel extremely stupid, but still wish it was so and one just uses the holes to rotate the pulley off the shaft. i found a few photos of similar shafts and they do not have any thread there but I asked a part supplier to check if there is any thread on a new pulley just in case.
your comments are greatly appreciated. even a small detail can spark a winning idea.
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MacPhid
Senior Member
In post 51 the photo with the mapp gas cylinder shows the crank area. It appears from the photo that part #'s 17 and 19 are still in place. I assume that bolt#17 is loose but in place to prevent damage to the threads in the crankshaft while using the puller?
The gear (#12) driving the idler gear and camshaft is slid over the keyway, then the bearing #16 and washer. All of these components should be inside the timing case cover.Once the bolt is loosened the pulley of course should slide off. Does the pulley have a keyway for drive, or is it friction fit to the shaft?
James
The gear (#12) driving the idler gear and camshaft is slid over the keyway, then the bearing #16 and washer. All of these components should be inside the timing case cover.Once the bolt is loosened the pulley of course should slide off. Does the pulley have a keyway for drive, or is it friction fit to the shaft?
James
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Waterant
Senior Member
they are not. this is just a steel pack I'm using to protect the shaft because there is a threaded hole there for bolt #17
I just tried Oxi torch inside the pulley around the shaft. no luck.
I opened a case with Yanmar tech support as per Luna's recommendation but i do not expect they will provide any useful advice here. It will be "contact a dealer" or "use a 3-jaw pulley remover".
MacPhid
Senior Member
Nick, the diagram is a bit misleading I think. Item 16 should be a bearing to support the end of the crank on the outboard side of the timing gear. A lot of load on that gear as I believe it's driving the intermediate gear, injection pump, camshaft and water pump.
Here's a similar diagram/parts manual showing the parts listed.
https://dieselpartseurope.com/media/onderdelen_catalogus/0CR10-M51503_en.pdf
James
Here's a similar diagram/parts manual showing the parts listed.
https://dieselpartseurope.com/media/onderdelen_catalogus/0CR10-M51503_en.pdf
James
porman
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The picture in post 66 shows what looks like the threads from one of the 6 bolts that holds the damper to the pulley. Do all 6 bolt holes go all the way through? Would it be possible to put a couple steel plates between the pulley and the block and use 6 extra long bolts to press the pulley off? Maybe in addition to a 3 jaw puller? I'm not at my boat so I can't check it myself.
Nick F
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Breaking news!
Just got my pulley off (its John Deere, not Yanmar) and the shaft is parallel (not tapered). The pulley was a mild interference fit.
It came off with a few days of penetrating oil plus a straight pull (see pic in earlier post).
Regards,
Nick
Just got my pulley off (its John Deere, not Yanmar) and the shaft is parallel (not tapered). The pulley was a mild interference fit.
It came off with a few days of penetrating oil plus a straight pull (see pic in earlier post).
Regards,
Nick
twistedtree
Guru
Have you seen this thread https://www.trawlerforum.com/forums/s3/yanmar-6ly3-v-pulley-removal-43589.html
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OP
Waterant
Senior Member
I got the pulley off today! 
Thank you for all the good ideas and, most importantly for stopping me from trying to cut it off - I think I would do much more damage if I tried to cut it.
If anyone is stuck with a stubborn pulley, this is how I did that:
1) I got a new torch Bernzomatic TS8000
https://www.amazon.ca/Bernzomatic-TS8000-Intensity-Trigger-Start/dp/B0019CQL60
I can confirm it runs much hotter than a less expensive torch i used before running from the same MAP bottle. Without a large Oxy - Acetylene setup, which i could not find for rent and is expensive for a one-time job, TS8000 is the next best thing.
do not bother with small Map/Oxy torches running from small bottles - i tried it - the flame is very small and does not heat much.
2) I had a custom plate made which was suggested on this forum. It's 1" thick steel plate with 6 bolt holes and 1 large middle hole for the central push screw.
3) The plate was screwed to the pulley by 6 M10 bolts class 12. Class 8.8 I used just bent. Also, 6 screws vs 2 helped to make more even pull, which probably helped. We tried a smaller plate with only 2 screws and it was getting bent without doing much.
4) I used the largest pulley remover screw I could find. It's 3/4" DIA 8", one from Princess Auto: https://www.princessauto.com/en/8-in-3-jaw-gear-puller/product/PA0008045992
it weighs something like 10LB and is a beast, but it could not do this job on its own without the plate, just broke a piece off the pulley.
6) I put as much tension as I could on the screw and heat the pulley for a few minutes to 150-200C all around
7) I started putting more pressure on the screw with 1/2 ranch and 5' pipe over it while lightly taping with a small hummer around the pulley.
8) worth mentioning that i did several heat/cool/penetrating oil cycles in the last 2 weeks and the last time after warming the pulley i applied 50/50 ATF/Aceton mixture but I'm not sure how effective all of this was because the pulley base goes well inside the cover and the penetrants probably did not even reach the shaft/pulley connection inside and whatever reached from the outside end did not go too far.
I think the faster heating and a huge force of leveraged 5' pipe did the trick but you need the hardware to sustain this force so nothing breaks before the pulley moves.
Thanks, everyone again for the help!
Thank you for all the good ideas and, most importantly for stopping me from trying to cut it off - I think I would do much more damage if I tried to cut it.
If anyone is stuck with a stubborn pulley, this is how I did that:
1) I got a new torch Bernzomatic TS8000
https://www.amazon.ca/Bernzomatic-TS8000-Intensity-Trigger-Start/dp/B0019CQL60
I can confirm it runs much hotter than a less expensive torch i used before running from the same MAP bottle. Without a large Oxy - Acetylene setup, which i could not find for rent and is expensive for a one-time job, TS8000 is the next best thing.
do not bother with small Map/Oxy torches running from small bottles - i tried it - the flame is very small and does not heat much.
2) I had a custom plate made which was suggested on this forum. It's 1" thick steel plate with 6 bolt holes and 1 large middle hole for the central push screw.
3) The plate was screwed to the pulley by 6 M10 bolts class 12. Class 8.8 I used just bent. Also, 6 screws vs 2 helped to make more even pull, which probably helped. We tried a smaller plate with only 2 screws and it was getting bent without doing much.
4) I used the largest pulley remover screw I could find. It's 3/4" DIA 8", one from Princess Auto: https://www.princessauto.com/en/8-in-3-jaw-gear-puller/product/PA0008045992
it weighs something like 10LB and is a beast, but it could not do this job on its own without the plate, just broke a piece off the pulley.
6) I put as much tension as I could on the screw and heat the pulley for a few minutes to 150-200C all around
7) I started putting more pressure on the screw with 1/2 ranch and 5' pipe over it while lightly taping with a small hummer around the pulley.
8) worth mentioning that i did several heat/cool/penetrating oil cycles in the last 2 weeks and the last time after warming the pulley i applied 50/50 ATF/Aceton mixture but I'm not sure how effective all of this was because the pulley base goes well inside the cover and the penetrants probably did not even reach the shaft/pulley connection inside and whatever reached from the outside end did not go too far.
I think the faster heating and a huge force of leveraged 5' pipe did the trick but you need the hardware to sustain this force so nothing breaks before the pulley moves.
Thanks, everyone again for the help!
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OP
OP
Waterant
Senior Member
I did try the same 10-ton hydraulic jack with a steel plate. Nothing broke, but the pulley did not budge and the jack was at the limit of the force it could produce.
OP
OP
Waterant
Senior Member
RT Firefly
Enigma
Greetings,
Mr. W. Huzzah!
Mr. W. Huzzah!
OP
OP
Waterant
Senior Member
I put a hammer handle between the crankshaft arm and the block (the oil pan is already removed. i tried a wooden hammer handle first and could see it's started to bent and was on the verge of cracking, so i put composite one instead and it handled it without any issues.
Another option would be putting some metal bar between the bolts holding the plate so it is rested against the floor or something solid on the block.
Comodave
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As much as I don’t like a few things about my 6CTAs, I am very glad I have them and not engines like yours. That surely was a PITA. Glad you got it off. I hope the new one goes on easier.
RT Firefly
Enigma
Greetings,
I wonder if never seize would be called for upon re-installation?
I wonder if never seize would be called for upon re-installation?
OP
OP
Waterant
Senior Member
RT Firefly
Enigma
Greetings,
Mr. W. Ah. I see the taper. I agree, don't heat the pulley when re-installing. I don't see any reason NOT to use never seize. I'd goop the shaft up and torque the nut(s) to recommended poundage and call it good.
One reason you may not see any rust is your generous application of penetrant may have washed any rust away.
Mr. W. Ah. I see the taper. I agree, don't heat the pulley when re-installing. I don't see any reason NOT to use never seize. I'd goop the shaft up and torque the nut(s) to recommended poundage and call it good.
One reason you may not see any rust is your generous application of penetrant may have washed any rust away.
twistedtree
Guru
Did it go BANG when it finally let go?
