Ironhead Transmission Assembly, Tutorial w/Pics

[Ferrous Head]

Iron Mick : vintage engines.

Vintage engines ? Mick, It's an Ironhead. Any more modern and it would be an electric motor.

Very skilled workshop used to working on Manx Nortons, AJS 7R's. G45's even.

Got them to do a small machining job on a set of cases for me. Off their own bat decided to "skim" the faces for me. Took about 3 mm off.

Caveat Emptor.

Funny, how when you take your car to the mechanic he says "Sorry Mate, take it to an Auto Elec." or Sorry Mate, take it to the radiator guy next door. "Sorry Mate, go see the Austo Trans Specialist on the corner." etc etc etc.

Bike mechanics just fix everything.

[Steve9]

Three mm?

That's criminal!

[NP72Iron]

Originally Posted by 4634indian

try a visual check. Roll the motor over on the cam side -. shim to level it off the primary cover mounting surface the best possible. Place bare counter shaft in the closed bearing
then mount the bare trap door without the open end bearing in there. Should be able to see any miss alignment of the shaft to bearing bore

So I had a bit of time after work and did as 4634indian suggested. I also picked up a different door for $25 to try both.
Here are the results:

This is the door that came with the motor

This is the other door

Both seem to have the c/s slightly to the left. I tried to get photos as straight-on as I could. Just eyeballing it, it appears the door that came with the motor puts the c/s a bit more centered than the other door.


Sent from my iPhone using Tapatalk

[4634indian]

sorry to see the results. need to address the righthand case welding

[rocketnorton]

yep looks like that to me too

[NP72Iron]

So just for the heck of it I went ahead to see what happens when I put in the other door and I don’t have that same binding with this door (at least not with the bolts out) but unfortunately, only the top right hand bolt will thread in. Would it mess up anything if I opened up the other holes a bit in order to line up with the holes in the case?


Sent from my iPhone using Tapatalk

[JB in NC]

Originally Posted by NP72Iron

So just for the heck of it I went ahead to see what happens when I put in the other door and I don’t have that same binding with this door (at least not with the bolts out) but unfortunately, only the top right hand bolt will thread in. Would it mess up anything if I opened up the other holes a bit in order to line up with the holes in the case?


Sent from my iPhone using Tapatalk

Won't hurt a thing. That's what you have to do when you swap doors.

Jim

[Ferrous Head]

Very common situation. Bolt holes aren't indexed to anything on the cases. The dowels hold the door in position, the bolts just need to hold the door to the case.

[Ferrous Head]

But you'll find it a bit like when your doing the shimming for the shafts. You'd be surprised how not having all 4 bolts torqued down correctly can affect the shimming operation. It can make the C/S bind.