[daniel]

has this happened to any one before?

Hi guys, I am shattered. I have a cracked right hand crank case. its where the engine is bolted to the frame at the rear.
the crack runs from the join in the middle down the back towards the neutral switch then under the bolt hole and ends behind the breahter tower.
to my horror i also discovered the engine bolt had sheared the nut.
Question is, is it worth a proper fix i.e. new case, complete engine strip and weld. or weld up in situ with new bolt?

It only happened about fifty kms ag, after hitting a sharp dip in the road.

AS luck would have it I had three days in the hills organized with some mates next week.

it still runs fine, but I need to fix pronto as it is my work transport, my reason for living............................

oh, its a 94/5 900, has less than 40,000 ks and ive had it for just over a year. mileage is debateable, I bought it from a dealer but thats another issue.

keen to hear if it has happened to any one else.

thanks , Daniel.

 

[Speeddog]

Unfortunately, there's been others here that have suffered the same fate...

http://www.ducatimonster.org/cgi-bi...=tech;action=display;num=1070798515;start=0#0

It can be fixed.

 

[mitt]

Sounds also similar to this post;

http://www.ducatimonster.org/cgi-bin/yabb/YaBB.cgi?board=tech;action=display;num=1077477992;start=

I don't know how it was resolved, it sort of disappeared off the board. Maybe you can contact the author if he/she is still posting.

mitt

 

[niuginisbk]

Daniel,
Hi There, i'm the one that had the same problem as your now facing. Look at the thread Speeddog posted & you'll get the whole story.

The other post by Mitt is from Winstone & as yet we are yet to hear the outcome of his delemar.

The crack you described is almost identical to the one on my bike, which is also a 95 900m. Mine wasn't actually cracked through the neutral switch. It went from the centre line of the casing at the rear, back underneath the neutral switch, up around the outside, through the middle of the earth strap mounting bolt & terminated in the casing behind the crank case breather.

Mine has done a few thousand k's since & is still OK.

I suggest you take the motor out, this is easy, then take it to the best Tig welder in your town & he'll be able to fix it. I actually welded the earth strap bolt hole over & built it up to act as another reinforcing web for the casing. They didn't weld up the neutral switch in mine, but i did need to do a bit of dremmeling to open up the lead in enough to screw the switch back in. If your crack is through the neutral switch, just weld it up & don't worry about the switch.

Oh, and all this was done without splitting the engine casing.
Turned out to be quite an easy job.

If there's anything else i can help you with on this please contact me any time.

Good luck! (it should be OK!)

PS: Winstone, if you see this, let us all know how your's is going.

 

[daniel]

thanks for the feed back guys, I checked out the threads and it seems like a commom(uncommon) problem.

but I am concerned as to why it occurred. I figured it was down to stress and a flaw in the casting .
I didn't realise that the rear bolt screwed directly in to the fframe, hece my horror at not seeing a nut on the end of it.

ordered a new bolt anyway and have a welder lined up who can do it. his main concern is the alloy itself, he says if it is more magnesium based it will be tricky, whereas if it is silicone based it will be easier.
anyone out there able to shed some light?
what sort of alloy does/did Ducati use in these cases?
my wife says I now have colour in my face today, yesterday was pretty grim.
thanks for the help, Daniel

 

[Norm]

I don't know about the alloy type, but I wonder if some of this is caused by the stock bolts. The fit of the bolts thru the engine cases isn't very good & of course, when one end is threaded & the other isn't, the pull on each side will be different. Maybe the Nichols bolts would cure the problem? I've got them on one of my bikes, but you guys are making me nervous, maybe I'll buy some more.

 

[slickmonster]

How much would it cost to replace the entire engine casing? Anyone know?

Also...there was a thread earlier about the paint bubbles on the engine casing...I know alot of ppl were getting them replaced...Is there any performance damage that this does? or is it just a nit-picky thing that since you paid X thousand dollars...the paint shouldn't be bubbling up...

Thanks

 

[niuginisbk]

Daniel,
The guy that did mine said the casing were good quality Aluminium.

He did say they weren't Magnesium alloy.

But he didn't say anything about the silica content.

But they did weld well & the filler rod also flowed well.

Maybe try your local Ducati agent or a wrecker & see if you can get a trashed one for your guy to practise on if your concerned.

 

[daniel]

niuginimonster, thanks.
I am still baffled as to why it occurred in the first place.
did you notice any strange vibrations prior to discovering the crack?
I was getting some annoying vibes during moderated acceleration but would go away when cruising.
I'm just wondering if the cause might be internal.
The bolt theory is worht pondering also.
I seem to recall Ducati superbikes having a problem with cracked cases but they were 888's I think.

I will be preping the job this weekend, hope to have it sorted next week .
keep you posted
daniel.

 

[niuginisbk]

Daniel,
yea I was tossing around the same thing, How?? Why??

Vibration - I'm not experienced enough with Monsters, nor V-twins as to how much vibration is normal. My mate with his HD V-Rod says his shakes & rattles & carries on a different RPM so i just assumed this was the norm.

The roads are pretty bad here, & i've hit some wopping pot holes at speed, also practicing Mono's is i guess hard on everything (chains Especially)

The bolt system doesen't make sense to me. The front Engine mount bolt has a nut on the end, this would allow some minimal pivoting. The rear bolt doesen't have a nut, the nut is part of the frame. This i have always thought was a bad design as there must be some totional forces fighting each other with this set up. Chris Kelly advised there is an aftermarket bolt kit that requires you to drill the thread out of the frame on the rear through bolt, this make a lot more sense to me. (reminds me i must get a set)

But all in all, I now honestly think looking at Mine 95 900M, Yours 94/95 900M & Winstone's 95 900M, that there must be a design fault &/or weakness in the casings on this model.

I remember Someone mentioned that later models had had numerous structural upgrades in design of the casings. So this to me says Ducati new they had a problem.

Did you take the engine out? What Prep Work are you doing?
They Dremeled a "V" grouve along the crack in mine before welding. I reckon my suggestion to fill/Bridge the earth strap mounting point is a good idea, this should add a bit of extra strength.

I had no adverse reppercussions from the welding, even the gasket, which they welded right up to where the casing halves meet doesen't weep oil. Just got a rather Gaudly looking weld if you look closely. not a wory to me considering how much new casings, strip & rebuild would have cost.

I hope the welding goes well & look forward to seeing your next post with everything back together & operational.

Regards,
Chris.

 

[Norm]

The motor bolts that you are refering to, Chris, are made by Nichols.

 

[niuginisbk]

Thanks Norm,
better put them on the shopping list along with the Nicholas Lightened flywheel.....hmmmmm