Today while cleaning my primary cover for my 1978 1/2 flh-80, I discovered 3 cracks.
#1 Crack is in the cover mounting flange of the clutch service hole, is about 1/2" long, and I'm confident a welder can fix me up quick.
#2 and #3 are on the outside of the cover about 1 1/2" on each side of the floorboard mount bracket. These cracks do not go clear through to the inside as I look visibly with a magnifying glass. Magnafluxiing may offer up a different perspective, and I may pursue that after a discussion here from you guys whom have been done this road before me.
My questions: 1) what can I expect concerning appearance from having cracks #1 and 2 repaired?
2) Does any of our forum members have a decent cover, with the floorboard mount, available to replace mine?
Thanks in advance for your advice.

 

Cracks by the mount look like parting lines from the mold to me but the cover is not in hand. Does the crack by the derby cover mount hole go all the way through?

 

Parting lines? I too thought this because the lines are perfectly straight. I pulled photos of other covers from the web, and they do not show these lines.

 

The straight lines are not cracks as mentioned above. The other line looks like a web in the aluminum that formed during the die-casting process which is also normal for die cast parts even today.

 

I also agree with the above comments. Does the small crack go all the way through? If not, try grinding/sanding it and see if it goes away.

ps you can't Magnaflux aluminum.

 

Thank you Road Captain and hellonewman. You are correect on both all accounts.
I polished up the front side at the derby cover and this perceived crack does not go through.
I'm good to go!

 

True, you need to use a dye penetration test.

 

Do they leak? You can only PT aluminum. Welding on that would be a disaster. If you do that, you would have to machine the gasket face more then likely.

 

Those aren't cracks, minor imperfections in the casting molds, common on mid & later 70's shovel stuff. They changed up the casting processes mid 70's. Later processes needed less cleanup and post machining.