Crack in bottom cover @ drain plug

[tatu]

So no sub cover on the bottom with a bunch of bolts holding it to the bottom of the engine....I didnt see an oil pan in the parts fiche either. I stand corrected then.

Well then, why cant you just take the engine to a shop and have them weld the crack by flipping the engine over??? Seems like that would be a viable option.

I would do this, then make sure the flat where the drain plu g sits is filed smoothly and use a dowty bonded washer/seal just nip it up and it will be fine.

[MidWestCoast442]

I like that idea, tatu. Forgot about dowty washers. I have thought about JBweld...but it will not prevent the crack from spreading like a TIG welder will. The dowty washer would prevent the cracks @ the threads from being a leaking issue.

I'll call a local motorcycle shop and see what they think about going through with this plan.

[MidWestCoast442]

I PM'd gspower about his cracked lower case which sounds identical to mine. Thanks, Chuck.

So this is what I have in-mind for fixing the issue without removing the lower case:

TIG weld the crack together, TIG weld a strap of 1/8" aluminum over the location of the crack to reinforce & prevent future cracking, smooth/file the drain plug flat, and use a dowty washer to seal the plug to the flat.

Thoughts?

[chuck hahn]

I was trying to wrap my head around why the one shop had told you they needed to weld it from BOTH sides.....when just welding it from the outside would seem sufficent to me. Like you just said..if it doesnt leak and it doesnt spread...done deal.

[MidWestCoast442]

Took the motor to a welding/fab shop in Santa Rosa. The owner seems to know his sh*t. He also rides and has done this procedure before.

The plan is to weld-up the crack, threads, hole, etc. Then drill & tap a new threaded hole for the same plug. He's also going to machine a groove into the plug and the flat of the lower crank case so that I can use an o-ring to seal it. Compressed air will be pushed into the crankcase during drilling/tapping so that metal shavings don't go in.

Will report after I pick it up...

[znsullivan88]

Glad I stumbled across this thread. Just chipped off a big ol' glob of JB weld on the drain bung of my gs400. had thought it was mud baked on the pan... but no. I'm going through my engine entirely so I already had planned take the case off and weld up the crack. Can you find out the process the guy at the machine shop took to weld it up? I had planned to drill a small hole at the end of the crack to take the stress off the metal from cracking more. wasn't sure if that was necessary.

pictures would be cool too.

[MidWestCoast442]

I'll ask him to detail the process for me and I'll post it on here. Should be picking it up later this week.

Sounds like drilling the hole wouldn't do much good for you. The plan, as he described to me, was to do a full weld-up -> drill & tap -> chamfer for o-ring on case & plug. The o-ring will help seal it without needing to torque the plug as tight - which should help to prevent future cracking.

[MidWestCoast442]

Okay. So the crack seems to be fixed.

Dan at Dan's Metal Works in Santa Rosa, CA did the work. He seems to be pretty sharp; says that he mostly works on Harley repairs because their junk is always breaking (hah!). The whole procedure cost me $100.

So he attempted to weld the crack & threads as-is, but the alloy doesn't weld very easily. So he did what he could, then started adding material on top of it to have something to work with. After layering metal over the crack and threads, he plugged the crank case except for one of the holes. He then connected his compressed air line to this hole and proceeded to positively pressurize the crank case with air while he drilled & tapped the new hole for the drain plug. After doing that, he chamfered and flattened the area around the hole, added an o-ring to the plug, and threaded it in. The end.

My only concern is that some metal shavings could be in the crank case, despite the positive pressure. The oil filter would pick these up, I think. But what about the transmission?

Thoughts?