Author Topic: Crank nose repair question (Read 6329 times)

jimfoo · « **on:** January 29, 2008, 05:26:17 pm »

I had the machine shop work on my crank so I could fit a TDI gear. The shop built up the whole crank for a tight fit, then ground the flat, but they didn't fill in the old slot. Is this going to be a problem? I imagine I could weld it up myself as the hardest part has been done, if it really needs it.

wyldman · « **Reply #1 on:** January 29, 2008, 07:05:31 pm »

I always weld them up first,then machine to fit.

I wouldn't weld it now,or you will need to remachine.

Check it for hairline cracks right around the keyway.If there are any,I'd be getting it fixed.

jimfoo · « **Reply #2 on:** January 29, 2008, 07:11:56 pm »

Well, I guess it would be hard for it to fail in the same manner. It is a good tight fit. Maybe I'll just JB Weld it as that can't hurt. I don't see any cracks, so I guess it isn't too bad.

wyldman · « **Reply #3 on:** January 29, 2008, 07:15:04 pm »

Did they magnaflux it ? Sometimes you cannot see the cracks.

Where did they machine the flat ? Is it 180 degrees away from the original keyway ? If so,you should be OK.I would not use any JB weld.

jimfoo · « **Reply #4 on:** January 29, 2008, 07:18:44 pm »

Nope, it's where the original keyway was. maybe I could make my own flat on the other side.

wyldman · « **Reply #5 on:** January 29, 2008, 07:20:46 pm »

Hmmm....

I have seen a few done like that and they later cracked.

You might want to consider welding it up properly,and remaching it.

935racer · « **Reply #6 on:** January 29, 2008, 09:39:24 pm »

If they machined the flat on top of the old key way it should be redone, I machine the flat 180 out from there all the time given the crank nose isn't damaged yet. If it is it gets welded up and re machined.

jimfoo · « **Reply #7 on:** January 30, 2008, 10:48:44 am »

Ok, I welded it up, about 3-4 times, and carefully ground it down, about 3-4 times, until I got it. It is now a tight press fit, I need to use the bolt to snug it up, and it has no movement. I can see where a mill or bridgeport would be very handy. I had to settle for a dremel, a very steady hand, and a very slow cutting diamond disc.

burn_your_money · « **Reply #8 on:** January 30, 2008, 11:23:06 am »

Do you have any pictures?

jimfoo · « **Reply #9 on:** January 30, 2008, 11:57:12 am »

While it isn't too bad, I don't think it is nice enough for pictures as the flash seems to magnify any little imperfection, making it look far worse than it is.

burn_your_money · « **Reply #10 on:** January 30, 2008, 12:07:47 pm »

it can't be any worse then if I did it, which I'll probably end up doing one of these fine days

Author Topic: Crank nose repair question (Read 6329 times)

935racer