Panhead case welding/repairs

[digspeed]

I have an idea to repair my cases.  As stated in my last post, I need some extensive welding done to the Panny!  I hate paying some one to do something that I could accomplish myself!  The repair that intimidates me the most is the right side pinion race.  The hardened part that is cast into the case is loose in the aluminum.  Has anyone out there done the repair?  Here is my idea. . . .

Jig the cases up in a EDM, and burn at least two, maybe three holes into both the aluminum and hard part.   Split the hole with the aluminum on one half and the steel sleeve on the other half of the hole.  Then press a dowl pin into the hole to "lock" the part back into its permanent position.  I'm thinking that pinning it in three positions should lock that sucker into position!  Any opinions out there?

Up to this point I have done all of my own machine work and tool building to rebuild my Panhead and would like to keep it that way if possible.

[Ultrashovel]

I have an idea to repair my cases.  As stated in my last post, I need some extensive welding done to the Panny!  I hate paying some one to do something that I could accomplish myself!  The repair that intimidates me the most is the right side pinion race.  The hardened part that is cast into the case is loose in the aluminum.  Has anyone out there done the repair?  Here is my idea. . . .

Jig the cases up in a EDM, and burn at least two, maybe three holes into both the aluminum and hard part.   Split the hole with the aluminum on one half and the steel sleeve on the other half of the hole.  Then press a dowl pin into the hole to "lock" the part back into its permanent position.  I'm thinking that pinning it in three positions should lock that sucker into position!  Any opinions out there?

Up to this point I have done all of my own machine work and tool building to rebuild my Panhead and would like to keep it that way if possible.

Hmmmm, that sounds rather drastic to me. First, if the bearing shell is truly loose, pinning it in place will likely cause it to move somewhat off center. Of course, you could then have it line bored again but if it's off a few thousandths, you won't find any oversized rollers to fill the gaps.

What I would do if the case is really loose around the bearing would be to have the bearing pressed out and weld and re-bore the case to either a press fit for a new bearing shell or the original shell. Properly done, the shell should be back where it belongs with a nice tight fit. It could be checked again with line boring equipment but if the welding and machining is properly done, it should be very close. 

I've seen this sort of thing done at an Indy shop where I used to go for machine work and boring, etc. so I know it would work. I'm familiar with the EDM process but I doubt I'd go that direction

One nice thing about Panhead era aluminum castings is that from my experience with them, I believe they are almost pure aluminum. Therefore they weld very nicely with some preheat, of course. The only welding I've done on Panhead engines myself is replacing exhaust stubs. In those cases, they weld beautifully and it makes a perfect repair. I've seen lots of welding done to repair Knucklehead and later crankcases, though and it can be very nice.

The machining would require some careful setup but people are doing this sort of thing all of the time now for converting the later TC's to Timken races. This type of repair was also very common on Matchless and AJS single clyinder bikes that I used to race. They had a small bronze bushing for the timing side bearing and they were forever coming loose, Usually, an oversized bushing could be made but sometimes, the case would crack or crumble around the hole and welding was needed.

One issue though that may stop a reasonable person is if the cost of the repair approaches the cost of a set of aftermarket cases. 

Good luck on this.

[chris haynes]

One issue though that may stop a reasonable person is if the cost of the repair approaches the cost of a set of aftermarket cases. 

Good luck on this.

Aftermarket cases can't be used on a restoration.

[digspeed]

The movement of the bearing shell is no more than .010, by rotating it or pulling it laterally.  Both set screws are missing, which may have contributed to the shell becoming loose, who knows?  If I go aftermarket, I no longer have matching cases, nor original HD.  I'm not a purist, but would like to keep the ol' girl fairly original.  Cases are a big one for me.
If I re-install the set screws, then proceed with the machining process, with no more than .001 press fit, how could it throw it out that far?  I realize that the race will need to be line lapped, but that is SOP when doing a rebuild.  Especially when "Kilroy" has been into my scooter! 
Just looking for ideas and feedback, no disrespect intended.
How can a machine shop press the old shell out, re-weld the hole, then press a replacement shell into aluminum?  Didn't the factory cast the original shell into the case during manfacturing? 
Maybe I should just apply some JB weld and call it good.  (joking)

[Ultrashovel]

The movement of the bearing shell is no more than .010, by rotating it or pulling it laterally.  Both set screws are missing, which may have contributed to the shell becoming loose, who knows?  If I go aftermarket, I no longer have matching cases, nor original HD.  I'm not a purist, but would like to keep the ol' girl fairly original.  Cases are a big one for me.
If I re-install the set screws, then proceed with the machining process, with no more than .001 press fit, how could it throw it out that far?  I realize that the race will need to be line lapped, but that is SOP when doing a rebuild.  Especially when "Kilroy" has been into my scooter! 
Just looking for ideas and feedback, no disrespect intended.
How can a machine shop press the old shell out, re-weld the hole, then press a replacement shell into aluminum?  Didn't the factory cast the original shell into the case during manfacturing? 
Maybe I should just apply some JB weld and call it good.  (joking)

I'm sure now that the races were replaceable.

The right side timing race is pressed into the case after the casting procedure. Since aluminum melts around 1,200 degrees F., I don't think they could have poured aluminum around a finished, hardened bearing. The heat would have annealed the bearing if that were the procedure. I jus tlooked on eBay and ther eis a complete race with needles and cages for sale for th etimin gside of a VL and also a 45. That shows that the bearings were relaceable. You need to check a parts book. The bearing race could be pressed out and then the case could be rebuilt.

I had a 1950 Panhead many years ago that I stroked with a set of UL 80" flywheels. I don't recall any set screws around the right timing side bearing race but, again, I could be wrong, it was a long time ago.

If you have .010 loose, are you saying that the race will move .010 from front to back or from side to side? That's an awful lot either way to hope that some pins might hold permanently. Some sort of a press fit would be more permanent.

I agree with you that original cases are a nice thing to have. Unfortunately, we are taking about bikes that are approaching 60 years of age and time will take its toll.

The guy who would know much more would be Craig in Arizona, one of the moderators here. He's a Panhead guy.

Good luck.

[stroker800]

   I have seen a simillar repair done to an Evo,,,,the entire race and metal was removed via large hole machined in case,,,,,4" hole..Then a new race and piece of alumimnum was jigged in and welded in place,,,this was from a mag,,,the shop specialized in Evo race fixes.......I got my cases and they were welded previoulsly and warped,,,my motor guy had his work cut out for him,,,,,good luck.
Dave

[mark61]

    Now a days there are companies that rebuild bearings for applications no longer manufactured and or make stock bearing fit custom applications. Check into Browning Transmition  and  or  bearing specialty companies. Where I work alot of our bears need to be refurbished or custom fit!  When I go back to work next week I will look for contact info.

mark61

[digspeed]

Using a dial indicator, I have measured the actual movement of the "shell" in the aluminum case.  Side to side is .012, up and down movement is .002, and movement when twisting the shell is .0035. 
The HD service manual shows two set screws that lock the pinion race into the shell.  The holes are threaded through the aluminum and the shell, then stop against the OD of the pinion race.
Maybe the movement is due to the fact that the set screws are missing, and when replaced all movement will stop? ? ?  Considering the screws thread into both the aluminum and the hard shell, replacement may be the cure!   Any thoughts?

[MBSKEAM]

look here...

















and a set of early pan cases that have been done....



this one had a crack show up after the welding and was fixed before it was finished.
my point is pull out the race holder, have the case welded up and back to a press fit. or you will be doing it all over in a few miles....
but hey, there's always time too do it right the 2nd time....LOL

I work with this guy, so I get to see a lot of pan and earlier cases get welded on....


mbskeam

[Ultrashovel]

Using a dial indicator, I have measured the actual movement of the "shell" in the aluminum case.  Side to side is .012, up and down movement is .002, and movement when twisting the shell is .0035. 
The HD service manual shows two set screws that lock the pinion race into the shell.  The holes are threaded through the aluminum and the shell, then stop against the OD of the pinion race.
Maybe the movement is due to the fact that the set screws are missing, and when replaced all movement will stop? ? ?  Considering the screws thread into both the aluminum and the hard shell, replacement may be the cure!   Any thoughts?

If you have that much clearance, the bearing has to come out and be replaced with a new one, probably by welding hte case and installing a new bearing. No set screw is going to hold that much clearance.