Cracked Right Case

[Geo]

I'm into the bottom end of a '57 FL and found the cam bushing had spun in the case. When I removed the bushing I found a small crack that ran up from the gear shaft's bearing boss on the gear side of the case. It then runs across the bottom of the cam bushing's bore to the inside of the case and back down.

I was told by a very good local mechanic that it would need to be plugged, welded and rebored. The shop where he works didn't want to touch it.

My question is why can't I just weld along the crack and mill it down on both sides. Then bore the hole to fit an oversized bushing? He says it will just crack again.

Maybe I need to let an expert handle this one. I don't know of a shop in the Dallas/Fort Worth area that specialize in this type of repair.

This is the first time I've ran across this problem but it can't be that rare.

Any suggestions, comments or recommendations ??????

[ozwick]

RE: Case Repair

I have heard good things about Head Hogs.

http://www.headhog.com/index.htm

[exeric]

Weld it and run it. I mean, what's your alternative. You aren't going to throw it away. I've had transmission cases that were badly cracked and I heard the same prognosis from experts, that "It's going to break again". A good welder can make a part structurally stronger than original and I would only grind the weld where you have to.

[Ohio-Rider]

Geo! If you have access to a reasonably competent machine shop in your area this would be a rather easy,simple repair. If not then take ozwicks advise and send it to Head Hogs.

As eric said. "Weld it and run it." Which leads us to discuss the proper method for this specific repair. I don't agree with your local mechanic as to "plugging" the hole and then remachining it.
Plugging the hole would add extra machining processes that don't need to be performed.
I would suggest:
1)-Setup cover and mill spots for future machining locations.
2)-Machine the exsisting diameter to 1/8 oversize to flatbottom.
3)-Weld diameter in vertical passes to achieve stock.
4)-Remachine I.D. and face to finish.

Forget what the experts say. It will not break again.

[MJW]

If you go with Headhog, be prepared to wait! Mike

[Lonnie]

You could try Tom Shaw at Creekside Welding. Website is www.creeksidemc.com, I believe. He has done repairs on several sets of devastated knuckle cases for guys from this area, me included, with good results. His website has several sets of photos you will find very interesting.
You could also try Carl Olsen, website www.carlscyclesupply.com. Carl does excellent restoration work and may be your man.
Lonnie

[MJW]

Don at Headhog does exellent case repair, He replaced both front motor mounts and the generator cradle on my 51 cases. The rear bolt holes were also re-worked. All for a very reasonable price too. But be prepared to wait...Mike

[Skip]

Don't be afraid to weld it and go...busted out a rocker mount hole this winter...took it to a local aluminum welder...had it re-tapped and there you go...sometimes welds are better than new....Skip

[Geo]

Thanks Guys, for taking the time to reply. Good and positive advice from all. I'm glad we have this forum to bounce ideas off people who share our passion. I've heard nothing but good about Don Sullivan. I spoke to him a while back about some head work so I know it takes a few months to get your parts back and he lets you know that up front. I've done business with Carl in the past and his work is indeed excellent. I'm tempted to shoot him an e-mail and see how long it would take him to get the job done but I think I'll do the repair myself using Ohio-Riders tech tips.

I need to get this old '57 on the road so I can sell the '54 pan. The '54 is fresh from the crank up with N.O.S. standard bore jugs. The cylinders have original silver paint. I just got it back together the other day so it has less than 50 miles on it now but I ride my bikes so the milage will go up. So if anyone is looking for a really nice anniversery panhead send me an e-mail at fishgeo@msn.com

Thanks again one and all.

[framemaker]

Has anyone ever worked out why the cases crack through this area. I've never been happy with the "its just a weak area" type answer. I have 6 sets of cases ranging from 1964 back to 1938 and none have the cam/pinion crack. I have another 2 right side cases that have cracks in this area. One looks like a road map.
Ocasionally I have seen the cracks go between the cam and pinion and then start heading down around the pinion race. Years ago a guy brought his 56 Pan chopper in for a service and said it was getting tappet niose every now and then. After doing all the easy checks and adjustments, I pulled a lifter block out to check the lobes of the cam. By chance, I spotted a crack that was running horizontally through the cam chest. I then pulled the cam cover off and could see the crack had run right across the flat section of the cam chest, just above the cam. As I turned the engine over by hand the crack would open up and and then close again. Needless to say, he didnt ride it home again for a while.

Is it the vibration from incorrectly balanced flywheels?
Incorectly set up flywheels eg. 005" or 015" run out on the pinion shaft?
Loose pinnion rollers.......or tight pinion rollers?
Constant running with really loose tappets.... smacking at the lobes of the cam?

Any one know?

No one mentioned it on their answers but I think preheat and postheat the cases before and after welding them. Getting a die grinder into the cracks and making a V along the crack to achieve penatration would be a good thing.
Steve

[MJW]

My 51 sure vibrates, I almost wish I would have gone back to 74". I'd rather have a smooth motor than a big one I'm afraid to open up for fear of blowing it all to hell. I'm learning a lot of lessons on this pan,.....Mike