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.

RH side engine cover

Under the RH side cover

Primary drive gear nut off

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.

Alternator cover puller helps splitting the cases

Cases split!

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.

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.

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 from the left side removed

Timing belt rollers, tensioners and protection plates removed

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.

Poor man's engine stand (packing foam) works well enough

Cylinder head

The piston was not taken off with the cylinder

Headnut tool

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.

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:

1. seat
2. fairings
3. fuel tank
4. air box
5. throttle bodies
6. side stand
7. center stand
8. exhaust
9. rider foot pegs
10. gear shift lever
11. rear brake master cylinder
12. clutch
13. alternator cover and flywheel

All of those things were pretty easy. I had bought a alternator cover puller earlier from eBay. A simple billet alloy one having three holes on it. It was a cheap one but seemed to do it's job. I hadn't removed the alternator cover earlier so had to be a bit cautious as it required some force to pull it out. The liquid gasket holds the cover pretty tight but came out smoothly after all by just slowly turning the puller bolt and pulling the cover with bare hands.

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.

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 :)

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 :)