Possible Ruined Crankcase?

[bkb88]

I am very worried that my right crankcase might be ruined. The bolt hole for the clutch cable bracket is leaking oil.

http://i100.photobucket.com/albums/m14/thebutelr/SANY0003-3.jpg

I took the bolt out and started up the bike to find the hole is spitting out oil & air. I am very confused on how this is possible being that it did not leak before I installed my XR400 clutch cover. The bolt is actually 5mm shorter than the 400ex bracket bolt. I cannot see how the bolt could have possibly made a hole through the crankcase but that is what it looks like... Any ideas on what could be causing the leak or experience with similar issues?

[bkb88]

I guess I found my problem unfortunately... The bolt hole goes all the way through the center case to the section where the cam chain passes through. I'm assuming the hole should not be threaded all the way through and there is no correct fix other than to replace the entire right center case...

I'm baffled as to how this is possible. One would assume the metal at the end of the threaded hole would be thick enough to make a bolt break off if it was torqued too tight instead of run right through the aluminum! I have not touched a bolt on this machine without using a torque wrench so I am guessing this problem must have been there all along... :mad:

If anyone wants to chime in with ideas on how to fix this or just moral support...please don't hesitate lol.

[400EXRAY]

So i take it that the orriginal bolt was too long and who ever owned it before you did this? my immediate concern would be the aluminum pieces that it pushed into the case. after that I'd dissassemble the engine and have the hole welded shut from the inside. that would be a relativly cheap weld job to do. you'd save alot of money and wouldn't have to worry about it leaking. just make sure to use a shorter bolt after that. Or you could be cheap and squeez some gasket sealer at the end of the bolt and screw that back in and hope it seals.

[bkb88]

Yeah I'm assuming it has been like this for some time. When I first purchased the bike the other mounting bolt was broke off inside the crank case so it wouldn't surprise me. I have cleaned out the metal screen on the right crank case a few times and each time there have been pieces of metal which I am assuming were part of the metal chunk that was pushed out. Any possible damage would have already happened so I am not worried about any lost chunks of metal floating around waiting to destroy my bottom end.

I really do not want to replace the crank case but that seems like the only option for a correct permanent fix. I would have it welded but it does not seem like the hole could be welded up as it is in a very narrow spot that houses the cam chain. Do you think there is a good chance of the gasket sealant stopping the leak or possibly using some thread tape? (just brainstorming haha).

[NMills]

Wow... i thought i was the only one.. when i put my engine back together i was puttin the clutch cover back on without the clutch cable holder and ended up pushin the bolt thru the wall into the Cam chain area... i fished out the chunks and put it together and never a leak at all...

[CJM]

Relatively easy fix, just time consuming.

Take the cover off, clean it really good-might have to bake it or something to get all the oil out. Then take it to a welder, have them weld it shut there to the depth you want and you drill and tap the hold for what ya want.


That or use a longer bolt I guess.

[bkb88]

Originally posted by NMills
Wow... i thought i was the only one.. when i put my engine back together i was puttin the clutch cover back on without the clutch cable holder and ended up pushin the bolt thru the wall into the Cam chain area... i fished out the chunks and put it together and never a leak at all...

We must be the most unlucky 400ex owners alive...lol. I'm still amazed that this could even happen :eek2: .


Relatively easy fix, just time consuming. Take the cover off, clean it really good-might have to bake it or something to get all the oil out. Then take it to a welder, have them weld it shut there to the depth you want and you drill and tap the hold for what ya want. That or use a longer bolt I guess.

So could this be done with the top end still intact? Or would it have to be stripped down to just the bottom end minus the right side crank case cover? I am starting to feel a little more optimistic about my situation now haha. It seems like when I get one project accomplished, (E.g. my new removable clutch cover!) something always ends up breaking...

[F-16Guy]

Use a bore brush and some type of solvent to clean the hole/threads and the bolt thoroughly, then, once everything is clean and dry, coat the threads with thread sealant and wet-install the bolt. Once it's dry, you should be good to go. In the aircraft world, we wet-install fasteners on a regular basis. It works very well as long as you get everything clean and dry before applying sealant.

[CJM]

F-16Guy makes a good point and it should work and of course be cheaper than welding it (well less time consuming anyways.)

To weld it you would need to take the bottom end down far enough they could weld in that area. Probably could clean it super well and so long as theres no oil residue they should be able to weld.

[bkb88]

Thank you guys for the suggestions. I used the method described by F16-Guy using Hondabond and it seems to have sealed up my leak! I will be taking the motor to have a permanent repair made on that bolt hole this winter. Maybe now I can actually get out and ride :rolleyes: .

[tri5ron]

Originally posted by F-16Guy
Use a bore brush and some type of solvent to clean the hole/threads and the bolt thoroughly, then, once everything is clean and dry, coat the threads with thread sealant and wet-install the bolt. Once it's dry, you should be good to go. In the aircraft world, we wet-install fasteners on a regular basis. It works very well as long as you get everything clean and dry before applying sealant. ^^ X2 ^^
I have over 26 years in aircraft assembly and repairs.
Pretty much every Barrier attachment installed, that is either a "Clearance fit" or "Close Tolerance fit", is installed "wet".