Ducati Monster Forum

Moto Board => Tech => Topic started by: Triple J on May 02, 2009, 02:11:00 PM

Title: Small Piece Broke Off Engine Case
Post by: Triple J on May 02, 2009, 02:11:00 PM
Well, looks like Murphy has showed up to help with my Multistrada project.  :-[

It's done, and I rode it on Thursday, but I wasn't happy with the oil cooler lines, or the cooler placement...so I ordered a set of fancy blue Hypermotard lines.

All was going well until I took out the upper oil cooler line fitting in the case. As I unscrewed it, a piece of the case broke off. I still screwed the new fitting in...see pic below...but you can see the gap behind the copper washer. The fitting screws in fine...there just isn't a flat face for the washer to bear against now on the outside.
(http://i114.photobucket.com/albums/n258/JJGeo/Multistrada%20Re-Build/IMG_0589.jpg)

Here's the piece that broke off. Notice is contains threads.
(http://i114.photobucket.com/albums/n258/JJGeo/Multistrada%20Re-Build/IMG_0592.jpg)

So...any idea how to fix it?  ??? I've heard of cases being welded, but this seems too small for that.

My idea is to JB weld the piece back on. Before it sets up I'll also cover the fitting threads with gasket maker and screw it in to the case. I'd do that after the JB Weld sets up, but the piece is so small, and it contains threads, so I'm worried it'll ruin the threads if the epoxy squeezes into them, and I won't be able to get the fitting back in. The downside is if the epoxy squeezes in like I expect and I've installed the fitting it's basically in there for good.

Thoughts??  ???
Title: Re: Small Piece Broke Off Engine Case
Post by: stopintime on May 02, 2009, 03:04:15 PM
Grind it down to a new flat surface?

I have no idea how, but I'm sure you do [thumbsup]
Title: Re: Small Piece Broke Off Engine Case
Post by: needtorque on May 02, 2009, 03:38:28 PM
My suggestion would be to have a good aluminum welder build that area up a bit with weld then grind it back to the original surface and re-run the threads.
Title: Re: Small Piece Broke Off Engine Case
Post by: woppini on May 02, 2009, 05:53:33 PM
nah, youll be fine. Take off the fitting, and clean all the metal in the area with brake cleaner. Use a cloth because the cleaner can soften the paint on the engine. There are two types of jb weld. A slow cure, and a "kwick set" The quick set is great cause you dont have to wait 24hrs for it to harden. Apply the weld in stages to build it up. As one layer begins to set up, add another. Add more than you need on the engine case so you can file it down as needed. File it even with the rest of the case mounting surface for the washer. Add a thin layer of automotive silicon (yes, it does come in gray, good stuff I might add) to the washer on both sides, and lightly cinch the fitting snug. 
Title: Re: Small Piece Broke Off Engine Case
Post by: ducpainter on May 02, 2009, 05:59:04 PM
Does it leak?
Title: Re: Small Piece Broke Off Engine Case
Post by: He Man on May 02, 2009, 06:30:54 PM
Quote from: ducpainter on May 02, 2009, 05:59:04 PM
Does it leak?

If it dont leak, and theres still threads below it, id say make the beast with two backs it, leave it as is. if its a sigh for sore eyes JB weld it back to shape and call it a day.
Title: Re: Small Piece Broke Off Engine Case
Post by: EEL on May 02, 2009, 06:46:49 PM
+1 on what he man said

Its not like that a fitting that comes off on a regular basis. A lot of us have the mentality of "fix it till it breaks". Leave it till its a problem. Keep the piece safe somewhere if you plan on welding it on later when a problem arises.
Title: Re: Small Piece Broke Off Engine Case
Post by: corndog67 on May 02, 2009, 06:46:58 PM
The only problem I can see with welding it, would be getting all the oil out of the area to be welded.   And that you are sure the center cases are aluminum, not magnesium.  My Yamaha has magnesium center cases, I think.  Either way, it can be welded.   And that would be the preferred way to fix it.   Personally, I'd pull that sucker apart, and fix it right, but I tend to get a little anal about things like that.   Of course, JB might stick it back together and not leak, but it would be stuck real good, and if you had to remove it later, that would be the time to pull it apart.
Title: Re: Small Piece Broke Off Engine Case
Post by: Triple J on May 02, 2009, 07:49:40 PM
Thanks for the suggestions guys.

I'm not sure if it leaks as is...the oil was drained when I took the fitting off. I may fill it with cheap oil so I can start it and see. I'm guessing it will though...although there is plenty of thread in the case. Threads alone usually aren't tight enough for fluids.

I'm leaning towards putting the piece back in with JB Weld. When the fitting is tight against it it will hold everything in place, so the JB Weld will mainly just be a gasket. Possibly use some automotive silicon on the copper washer so I don't have to crank the fitting down too tight. If it doesn't leak, then done...if it does then I'll have to do find someone to weld on it. I really don't want to take everything apart!
Title: Re: Small Piece Broke Off Engine Case
Post by: He Man on May 02, 2009, 08:10:33 PM
Use the liquid gasket they use for gas pipes then put it back in.
Title: Re: Small Piece Broke Off Engine Case
Post by: BK_856er on May 02, 2009, 09:44:54 PM
I don't have any useful repair suggestions, but here's a pic of the insides in case it helps.

Be careful with a hack repair...you don't want to spring a leak at that location and cause your own crash!

(I'm going to make a mental note to heat the threadlocker before I unscrew my oil line fittings again, just in case that was a contributor here)

BK

(http://i43.tinypic.com/25872bm.jpg)

Title: Re: Small Piece Broke Off Engine Case
Post by: Langanobob on May 02, 2009, 10:54:13 PM
I think if  it were mine I'd J-B Weld it back, using the old fashioned slow cure J-B Weld because I think there's a strength compromise in the fast cure 5 minute stuff.  I'd clean it real good first, and stick it  back on with  J-B Weld without the fitting in place to avoid any possibility of J-B Welding the fitting in place.  I think I'd find a small stick or something similar to wedge it in place while the epoxy is curing.  You don't need to clamp it real tight  as the epoxy requires a little bit of thickness to bond well, but you do  need to make sure it's perfectly aligned and doesn't move.  Then when it's cured I'd chase the threads with a tap.

Of course you could very lightly grease the threads on the fitting and epoxy it with the fitting screwed in too.  But there's still a chance it might stick.

Welding is the best long term solution but I'd wait 'til I was tearing the engine down for some other reason.

If you want to try and leave it the way it is for awhile, Loctite works pretty good at sealing threads and Loctite makes special green colored hydraulic thread seal stuff although off hand I don't know the part number.   
Title: Re: Small Piece Broke Off Engine Case
Post by: aaronb on May 03, 2009, 05:04:14 PM
jb weld the whole thing, threads and all.  you will not be able to remove the fitting ever again, but who cares?  the Cu crush washer does the sealing, so that will never work properly again without welding and facing the case.  a think coat of jb weld on the threads will seal just fine. 

get the normal set time stuff too, the max temp for the quick set is only 300F

from mcmaster-carr catalog:
QuoteMaximum temperature is 500°  F for 8265-S and 8280 epoxies; 300°  F for 8276 epoxy.
Title: Re: Small Piece Broke Off Engine Case
Post by: desmopr on May 03, 2009, 06:33:34 PM
I would first see if it leaks.  If it doesn't, leave it as is.  If it does, I would JB weld there some kind of adapter that I would then screw the oil line fitting on it.  Just thinking out loud, hope you can work it out.
Title: Re: Small Piece Broke Off Engine Case
Post by: Duck-Stew on May 03, 2009, 06:55:44 PM
Quote from: Langanobob on May 02, 2009, 10:54:13 PM
I think if  it were mine I'd J-B Weld it back, using the old fashioned slow cure J-B Weld because I think there's a strength compromise in the fast cure 5 minute stuff.  I'd clean it real good first, and stick it  back on with  J-B Weld without the fitting in place to avoid any possibility of J-B Welding the fitting in place.  I think I'd find a small stick or something similar to wedge it in place while the epoxy is curing.  You don't need to clamp it real tight  as the epoxy requires a little bit of thickness to bond well, but you do  need to make sure it's perfectly aligned and doesn't move.  Then when it's cured I'd chase the threads with a tap.

Of course you could very lightly grease the threads on the fitting and epoxy it with the fitting screwed in too.  But there's still a chance it might stick.

Welding is the best long term solution but I'd wait 'til I was tearing the engine down for some other reason.

If you want to try and leave it the way it is for awhile, Loctite works pretty good at sealing threads and Loctite makes special green colored hydraulic thread seal stuff although off hand I don't know the part number.   

+1

Heres' the order I'd try the above in:

#1 If it don't leak: make the beast with two backs it.

#2 If it do leak: green Loctite it.  (see #1)

#3 If it still leak: try the regular set JB-Weld as described above.  (see #1)

#4 Contact a welder/aluminum (Ducati cases are cast aluminum BTW) to see about repairing it...
Title: Re: Small Piece Broke Off Engine Case
Post by: Triple J on May 04, 2009, 08:43:08 AM
Thanks for the input everyone.  [thumbsup]

I'm going to do #3 above, along with #2. I'm impatient, so if that doesn't work I know right away I have to jump to #4.  ;D Maybe I'll try #1, but I can't imagine it won't leak...and that entails filling it with oil again, then immediately draining it, and cleaning the break locataion (again), if it does.  :P