Was time to put the new bearings in to freezer and crank case halves to owen. The bearings spent abot a day in the freezer and the crank case halves were cooked for about an hour at 150 degrees in the owen. The workshop manual suggested 100C for removing the bearings but I thought the warmer the case is, the easier it is to get the bearings in. Besides there wasn't anything that could be damaged with that heat.
Main bearings and lay shaft bearings were the easiest as the bearing being at -18C and crank case half being at 150C the bearing went in without any interference. As a matter fact there was even a small clearance for a few seconds which disappeared rather quickly and the bearing didn't come off anymore. At least those should be straight as they literally hit the bottom.
Gearbox main shaft and timing shaft bearings were much harder and I actually had to tap the outer ring with a socket to get them in. They were also in the freezer but they are so small that the case heats them up so quickly. Tapping still requires probably much less force than just having both in room temperature.
Swingarm bearings and seals are still on the table. Those also seemed to be pretty tight but heat gun and cold spray should do. After that I get to real business measuring the crank shaft end float and required shimms. First I need to find the smallest ones since I'm a bit afraid I don't get any float with the original onces.
2013-08-22
Bearings off
The last time I got the crankshaft removed so what was left, was removing the bearings and stud bolts. I would have left the stud bolts in place if my owen was big enough but unfortunately it isn't. Anyway it turned out to be a good choise since when heating the crank half in the owen the bearings came out almost by themselves. Much more convenient than with heat gun which takes ages to heat up.
Once I got the bearings removed I took the halves to a local machinery shop for washing. A quick way to get them clean even though the result could have been better. I think the only way to make it look like a new would be to boil them in sodium hydroxide. I didn't have facilities for doing that though and besides would rather practise with something cheaper since sodium hydroxide corrodes aluminium and therefor there's a possibility to ruin the cases. Well, they now look much better than earlier.
Currently there's no Ducati's importer in Finland as the previous one got fired or quit after 20 years, don't know the details, but it makes getting parts locally a bit hard. I would have liked to know the price at least even though I probably had ended up ordering the parts from Germany or Italy since they usually are pretty expensive here. I decided to change all the bearings except for heads and water pump, all the gaskets, seals and o-rings and belts. The total price was a bit over 700 euros including postage fees etc. Just the mains would have been ~150 euros total but wasn't up for saving here since the engine was already in pieces. Even though the price might sound high, if you take your Ducati for 20k km service (belts, valves, etc) the price is somewhere above 1000 euros in here. So yeah, you get most of the downstairs renewed cheaper. Own spare time is free of course :)
Once I got the bearings removed I took the halves to a local machinery shop for washing. A quick way to get them clean even though the result could have been better. I think the only way to make it look like a new would be to boil them in sodium hydroxide. I didn't have facilities for doing that though and besides would rather practise with something cheaper since sodium hydroxide corrodes aluminium and therefor there's a possibility to ruin the cases. Well, they now look much better than earlier.
Currently there's no Ducati's importer in Finland as the previous one got fired or quit after 20 years, don't know the details, but it makes getting parts locally a bit hard. I would have liked to know the price at least even though I probably had ended up ordering the parts from Germany or Italy since they usually are pretty expensive here. I decided to change all the bearings except for heads and water pump, all the gaskets, seals and o-rings and belts. The total price was a bit over 700 euros including postage fees etc. Just the mains would have been ~150 euros total but wasn't up for saving here since the engine was already in pieces. Even though the price might sound high, if you take your Ducati for 20k km service (belts, valves, etc) the price is somewhere above 1000 euros in here. So yeah, you get most of the downstairs renewed cheaper. Own spare time is free of course :)
2013-08-12
Removing the crankshaft
It's been a while since the last update since there wasn't too much progress before I got removing of the primary drive gear removed which I couldn't do myself. Well, now pretty much everything is apart.
The gearbox comes out in a few different pieces. Started by removing the fork guide shafts and once they are off the fork drum comes off. When it's off, there's enough room to pull out the forks and finally the main shaft and the lay shaft can be taken out in one piece. At least for now I didn't separate the gears since the bike didn't have much mileage on it and the gears show no worn. Still need to make sure they are well cleaned and oiled before reassembly.
As I mentioned, I don't have the tool to remove the primary drive gear which I've heard, pretty much requires the OEM tool for the job since it's pretty damn tight. There were ones on eBay for about 140£ which is about 160€. I wouldn't have been in a bankruptcy because of that but for a one time job didn't sound like it's worth it. Besides my usual part supplier guy mentioned about his friend who has the tool and is willing to help so I paid a visit and it was really worth the drive even though he doesn't live exactly the next door. He has been working with Ducati engines since eighties, been racing with Ducatis and at some point even servicing the bikes as a sub-contractor for the local shop. He really was very helpful and got tons of invaluable tips for the rebuild so I ended up spending couple hours there even though the job itself didn't take even half an hour.
Obviously the gear didn't get off just by talking. Turned the puller with impact gun for a while and nothing happened. This wasn't even my cheap one but his professional tool. So applied some good heat with electrical heat gun and tried again. Still took a while, but finally popped off, yay.
I still had the timing belt drive shaft in place as my self made tool didn't work too well and didn't have time to fine tune it yet. Well, got the belt gears off on the same trip. Finally asked some opinions about the crank preload and he suggested using a dial gauge and thinnest possible shims to measure the crank play and then calculate the correct shims. That's the alternative method described in the workshop manual. Measuring crank and the cases is quite tricky according to him but I still think I try that just out of curiosity and see how close readings I get. I think I still count on the "alternative" method if the readings aren't too close.
Worth mentioning that the timing belt drive shaft has one symmetric woodruff key and one offset one so I took a picture of it to remember that on reassembly. So the timing on horizontal cylinder doesn't seem to be exactly the same as the vertical. The difference isn't really big but I suppose the key has offset for a purpose.
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The gearbox comes out in a few different pieces. Started by removing the fork guide shafts and once they are off the fork drum comes off. When it's off, there's enough room to pull out the forks and finally the main shaft and the lay shaft can be taken out in one piece. At least for now I didn't separate the gears since the bike didn't have much mileage on it and the gears show no worn. Still need to make sure they are well cleaned and oiled before reassembly.
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Obviously the gear didn't get off just by talking. Turned the puller with impact gun for a while and nothing happened. This wasn't even my cheap one but his professional tool. So applied some good heat with electrical heat gun and tried again. Still took a while, but finally popped off, yay.
I still had the timing belt drive shaft in place as my self made tool didn't work too well and didn't have time to fine tune it yet. Well, got the belt gears off on the same trip. Finally asked some opinions about the crank preload and he suggested using a dial gauge and thinnest possible shims to measure the crank play and then calculate the correct shims. That's the alternative method described in the workshop manual. Measuring crank and the cases is quite tricky according to him but I still think I try that just out of curiosity and see how close readings I get. I think I still count on the "alternative" method if the readings aren't too close.
Worth mentioning that the timing belt drive shaft has one symmetric woodruff key and one offset one so I took a picture of it to remember that on reassembly. So the timing on horizontal cylinder doesn't seem to be exactly the same as the vertical. The difference isn't really big but I suppose the key has offset for a purpose.
2013-07-27
Cases split
Today I started with removing the right side cover. Wasn't really hard to remove - just unscrew the bolts and that's it. The sealant didn't hold the cover too tight but it took a while though. Would have been hander if I had removed it while the engine was in the frame as there's the primary drive gear nut underneath the cover and it's pretty tight and now I didn't have anything to hold the gear against. But again, the cheap pneumatic impact gun saved the day and the nut was easy to remove after all.
I took the pistons off before undoing the nut to avoid damaging them if
the gear slips out from hand for some reason. Lost one piston locking
ring though but maybe I'll find it later, or then just get a new one.
The factory manual suggested using the alternator cover and it's puller for splitting the cases so I put two blocks of wood under the engine and turned it sideways and tried what happens when turning the puller's bolt, after unscrewing all the engine retaining bolts from both sides of course. There didn't seem to be anything holding the cases too tight together so turning the bolt slowly and a few pretty gentle taps with a rubber hammer to gearbox transmission shaft did the job.
I thought before I wouldn't find anything interesting on the flywheel side since the original noise sounded like it was coming from the right side of the engine. Though it's hard to tell for sure and the source of the sound waves perhaps can't be located accurately just by listening. I'm sort of happy of what I found since it indicates that there's definately something wrong with the bearings. The inner race seems to be toasted but only about half of the race. Also the same half of the inner side of the ring looks like polished but couldn't get a clear picture of it with my cellphone camera and I don't have anything better for the photos. Would this be an indication of too tight crank? If it is, the bearing on the RH side should probably look pretty much the same. Going to find out soonish but first I need to get the primary drive gear off.
I still have the timing belt pulleys on since didn't find suitable tool for the job so need to figure something out for it. For the primary drive gear I know a guy who has the puller, just need to pay a visit there.
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The factory manual suggested using the alternator cover and it's puller for splitting the cases so I put two blocks of wood under the engine and turned it sideways and tried what happens when turning the puller's bolt, after unscrewing all the engine retaining bolts from both sides of course. There didn't seem to be anything holding the cases too tight together so turning the bolt slowly and a few pretty gentle taps with a rubber hammer to gearbox transmission shaft did the job.
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| Inner race of the LH side main bearing. Doesn't look healthy. |
I thought before I wouldn't find anything interesting on the flywheel side since the original noise sounded like it was coming from the right side of the engine. Though it's hard to tell for sure and the source of the sound waves perhaps can't be located accurately just by listening. I'm sort of happy of what I found since it indicates that there's definately something wrong with the bearings. The inner race seems to be toasted but only about half of the race. Also the same half of the inner side of the ring looks like polished but couldn't get a clear picture of it with my cellphone camera and I don't have anything better for the photos. Would this be an indication of too tight crank? If it is, the bearing on the RH side should probably look pretty much the same. Going to find out soonish but first I need to get the primary drive gear off.
I still have the timing belt pulleys on since didn't find suitable tool for the job so need to figure something out for it. For the primary drive gear I know a guy who has the puller, just need to pay a visit there.
2013-07-25
Heads off
Finally on a holiday! Even though most of the spare time was booked before I started the poject, managed to give the baby a little attention.
Gears on the left side were very co-operative coming out and didn't have any issues there. The starter motor tried to put some drama to the table however since the first bolt I tried to open snapped without any losening. Great. Luckily it was the only one so I got the starter motor off. I measured the depth of the threads on the starter motor and it seems that the depth plus the thickness of the engine pretty much equals the length of the bolt. So the snapped bolt is stuck to the bottom of the starter motor's hole. Sounds a bit scary since if the bolt is too long, it may not be possible to tighten the bolt enough. So I need to check if shorter ones are necessary.
The head nuts were pretty damn tight. Looked like the baby wanted to keep her heads, but me and Mr. WD-40 disagreed. Still too tight to turn with open-ended wrench as it might break the nut or maybe I'm just a bit overly cautious, but the box-end side was too thick. Luckily my father had made a special tool for removing the heads for valve adjustments so that one came in handy. There's an OEM tool as well, but my father wasn't the kind of man who would buy one if you can make one by yourself even if it was a cheap one :)
The horizontal head came out easily and the cylinder stayed on it's place but the other head was so tight that the cylinder came out with the head and also managed to slip the piston out from the cylinder. No biggie, was asking for advice from the forums whether to take the pistons out or not and thought I'm gonna leave them inside. Well, now I just need to get piston ring compressors which are affordable.
Finally managed to separate the vertical head from the cylinder, but it was pretty damn tight. I cut the liquid gasket with a piece of a sharpened soft plastic but didn't help. There are small guide rings that apparently are there to prevent any vertical play between the cylinder and the head and one of them was stuck in both sides but finally the head side gave up and came out. Seemed to be a bit corroded so maybe the sealing wasn't as good as it could be last time the heads were off. I'm sure I at least try to be much more careful.
Next I'll continue with removing the right side cover. Hopefully today.
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| Gears from the left side removed |
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| Timing belt rollers, tensioners and protection plates removed |
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The head nuts were pretty damn tight. Looked like the baby wanted to keep her heads, but me and Mr. WD-40 disagreed. Still too tight to turn with open-ended wrench as it might break the nut or maybe I'm just a bit overly cautious, but the box-end side was too thick. Luckily my father had made a special tool for removing the heads for valve adjustments so that one came in handy. There's an OEM tool as well, but my father wasn't the kind of man who would buy one if you can make one by yourself even if it was a cheap one :)
The horizontal head came out easily and the cylinder stayed on it's place but the other head was so tight that the cylinder came out with the head and also managed to slip the piston out from the cylinder. No biggie, was asking for advice from the forums whether to take the pistons out or not and thought I'm gonna leave them inside. Well, now I just need to get piston ring compressors which are affordable.
Finally managed to separate the vertical head from the cylinder, but it was pretty damn tight. I cut the liquid gasket with a piece of a sharpened soft plastic but didn't help. There are small guide rings that apparently are there to prevent any vertical play between the cylinder and the head and one of them was stuck in both sides but finally the head side gave up and came out. Seemed to be a bit corroded so maybe the sealing wasn't as good as it could be last time the heads were off. I'm sure I at least try to be much more careful.
Next I'll continue with removing the right side cover. Hopefully today.
2013-07-14
The engine is on the table
The engine is finally on the table. I tried to keep as many things possible things in place to avoid figuring how to re route electircal connections etc on assembly.
Before unmounting I removed:
The torgue on the flywheel nut (Generator rotor nut) seems to be 270 Nm in the Workshop manual, so some resistance was expected. I've read from other sources that it has a high torque and some permanent locktite on it, but that may depend on model as the workshop manual lists only engine oil and no locktite for it. Need to figure it out when putting it back to one piece. The removal was pretty easy however. I didn't have a tool to hold the flywheel so I used a pneumatic impact gun and held the flywheel in place just with the other hand. My compressor is a small one and the impact gun is a cheap basic one but didn't require anything fancier.
Workshop manual lists a special tool 88713.1515, engine/frame support. That's used to connect the swingarm to the frame when you remove the engine, but doesn't seem to be a mandatory one, depending how are you going to remove it. I decided not to take the rear shock off if possible so I welded similar tool out of some junk 19mm steel pipe (two of those supports) and it seemed to do it's job with a little help.
I strapped the tools as it seemed that the swigngarm wants to move forward because there isn't any kind of support on horizontal axis. This was enought to prevent it from moving.
To remove the engine I had two firends helping me out. I don't (yet) have anything on the ceiling I could use to lift the bike up so I just piled wooden plates under the engine to get the rear wheel up a bit. Then I hammered the swingarm axle out which didn't want to come easily. It required some serious force in the beginning but didn't get damaged or anything. Engine was free to go once the frame mount bolts were removed. We lifted the engine a bit and removed the wooden plates one by one to get the it lower. I didn't remove the heads or belt covers but there was enough room to take it out. Finally when the plates were removed I lifted the rear of the bike and a friend carried the engine to the table. I had no clue how much would the engine weight so was prepared to carry it with two of us. If I had some ceiling mounted lifter I think I could have removed the engine even alone using the same method. But doesn't hurt to spend some time with friends as well :)
So far it has been pretty easy. Can't really figure out the real hours and the blog posts so far are written on a same day because didn't know if I'm gonna write one or not. Next coming up the engine disassembly. Need to find some time to do that.
Before unmounting I removed:
- seat
- fairings
- fuel tank
- air box
- throttle bodies
- side stand
- center stand
- exhaust
- rider foot pegs
- gear shift lever
- rear brake master cylinder
- clutch
- alternator cover and flywheel
The torgue on the flywheel nut (Generator rotor nut) seems to be 270 Nm in the Workshop manual, so some resistance was expected. I've read from other sources that it has a high torque and some permanent locktite on it, but that may depend on model as the workshop manual lists only engine oil and no locktite for it. Need to figure it out when putting it back to one piece. The removal was pretty easy however. I didn't have a tool to hold the flywheel so I used a pneumatic impact gun and held the flywheel in place just with the other hand. My compressor is a small one and the impact gun is a cheap basic one but didn't require anything fancier.
Workshop manual lists a special tool 88713.1515, engine/frame support. That's used to connect the swingarm to the frame when you remove the engine, but doesn't seem to be a mandatory one, depending how are you going to remove it. I decided not to take the rear shock off if possible so I welded similar tool out of some junk 19mm steel pipe (two of those supports) and it seemed to do it's job with a little help.
I strapped the tools as it seemed that the swigngarm wants to move forward because there isn't any kind of support on horizontal axis. This was enought to prevent it from moving.
To remove the engine I had two firends helping me out. I don't (yet) have anything on the ceiling I could use to lift the bike up so I just piled wooden plates under the engine to get the rear wheel up a bit. Then I hammered the swingarm axle out which didn't want to come easily. It required some serious force in the beginning but didn't get damaged or anything. Engine was free to go once the frame mount bolts were removed. We lifted the engine a bit and removed the wooden plates one by one to get the it lower. I didn't remove the heads or belt covers but there was enough room to take it out. Finally when the plates were removed I lifted the rear of the bike and a friend carried the engine to the table. I had no clue how much would the engine weight so was prepared to carry it with two of us. If I had some ceiling mounted lifter I think I could have removed the engine even alone using the same method. But doesn't hurt to spend some time with friends as well :)
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Preparing the engine removal
I kind of hoped I had taken more pictures of the process, but was too lazy since the beginning was pretty basic stuff: Remove the fairings, remove the fuel tank etc.. I did take some though to document things like fuel line and cooling routes.
Fuel lines go near the clutch between the frame and belt covers. They seemed to get a bit tight when the fuel tank is lifted up. The route seemed to be pretty much the shortest possible with the current hose length so only longer ones would help. Hasn't been that big of an issue however.
Cooling system is a pretty straight forward too but probably doesn't hurt to take a couple pictures of that as well.
The upper cooling line from the radioator goes to vertical cylinder and has a temperature sensor attached.
The lower line goes to a joint, continues to horizontal cylinder head and to water pump. There's also a line from cylinder head to water pump's lower connection and similar one to vertical cylinder.
Not sure which way the coolant flows and didnt put too much worry on it since the workshop manual / LT Snyder book knows If I need to know. All I know is that there's endless flow of coolant even after a careful bleeding of the system when you disconnect the hoses. A drop here and there, mostly on your hands or your clothes :)
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Cooling system is a pretty straight forward too but probably doesn't hurt to take a couple pictures of that as well.
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The upper cooling line from the radioator goes to vertical cylinder and has a temperature sensor attached.
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Not sure which way the coolant flows and didnt put too much worry on it since the workshop manual / LT Snyder book knows If I need to know. All I know is that there's endless flow of coolant even after a careful bleeding of the system when you disconnect the hoses. A drop here and there, mostly on your hands or your clothes :)
Background
So I have a Ducati ST4s 2001 that seems to suffer from premature main bearing failure. The bike has been standind for a while now since I haven't had a place or time to take the engine apart. The engine started making supercharger noise even though I'm pretty sure there isn't one installed. I headed to ducati.ms forums and searched around the web and found this thread. There was a Youtube video of a similar bike with bad main bearing. Also another sound clip of one that was suspected to have the same issue. That didn't look good since my one had pretty much the same sound it was making. It wasn't the clutch pressure plate bearing as it makes the same even without the clutch. It didn't seem to come from the valvetrain system either and the pitch was pretty low to be caused by any small bearing. There's only 40k km on the bike so many things seemed to match to the previous cases.
I figured the only way to find out for sure is to remove the alternator cover and flywheel and test if there's any play on the crank. That would have been a clear indication but without any play things would get a bit more complicated since the bearing has to be inspected as there's still the noise.
I'm no mechanic from my background but I've been doing the basic belt change and valve adjustment jobs for my ST2. I've never taken any engine completely apart so I was a bit concerned whether I'm up for the job or not. I already had most of the required tools, I'm quite pedantic by my nature, I've been interested in mechanics since I was a kid and taken many things apart, maybe with a bit various success on the re-assembly side, I had the books that should cover the job pretty well and finally got an own garage so I decided to take the challenge.
I also thought it would be a good idea to document things and a blog seemed to be a good option compared to millions of notes in the garage with oily fingerprints on them and pictures here and there. Besides you never know if someone else finds the blog useful or some other way interesting :)
I figured the only way to find out for sure is to remove the alternator cover and flywheel and test if there's any play on the crank. That would have been a clear indication but without any play things would get a bit more complicated since the bearing has to be inspected as there's still the noise.
I'm no mechanic from my background but I've been doing the basic belt change and valve adjustment jobs for my ST2. I've never taken any engine completely apart so I was a bit concerned whether I'm up for the job or not. I already had most of the required tools, I'm quite pedantic by my nature, I've been interested in mechanics since I was a kid and taken many things apart, maybe with a bit various success on the re-assembly side, I had the books that should cover the job pretty well and finally got an own garage so I decided to take the challenge.
I also thought it would be a good idea to document things and a blog seemed to be a good option compared to millions of notes in the garage with oily fingerprints on them and pictures here and there. Besides you never know if someone else finds the blog useful or some other way interesting :)
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