pulling the gearcase off my '72. got the primary removed. i'd like to get the countershaft sprocket off to make it easier to wiggle the gearbox out. i need to know the size of the lh nut. figure to buy an offset box wrench. can you even get the gearbox out w/ the sprocket still attached?

on a side note; this is supposed to be a non combat '72. there's no c stamp i can find on the head. counted the sprocket teeth at 20, isn't 22 std.? where the head mates to the jugs the gap between the fins is definitely less than between the other fins. it came w/30mm amals. prolly the po changed some stuff around. thanks, from rick in bone chilling southern indiana

rgrigutis wrote:where the head mates to the jugs the gap between the fins is definitely less than between the other fins.

That's normal, regardless of whether the head is the Combat type or not, the gap between the upper barrel fin and the lower head fin will be noticeably less than the distance between the other fins.

Rgrigutis
I think a 1 1/2" socket will work on that LH nut. it is tapered on one side to accommodate the concave of the sprocket.
Regards,
CNN

I bought a trailer hitch ball wrench (double box end) at Pep Boys, the bigger of the two ends fits the sprocket nut perfectly.

You don't need to remove the sprocket to remove the tranny, or get the gearbox out of the cradle, but you do need to at least remove the bolts holding the rear end of the engine in the tranny cradle, then tip it forward enought to allow clearance for the tranny to rotate to the point where it can come out.

1-1/2 AF wrench or socket works great. Left-hand thread, and as I recall, a bend-over-the-tabs washer (forget the real name) to hold it in place.

You certainly DO NOT need to remove it to get the gear box out; it won't affect that at all. But if you're going to tear the gearbox down and that involves removing the mainshaft (e.g., to replace mainshaft bearing) it's easier to do so with the gearbox in place, chain on the sprockets, in high gear with rear brake on.

You can do it on the workbench, though, either with a bit of chain chucked into a vise to hold the sprocket in place (I did this, but can't remember quite how) or simply by chucking the sprocket itself into the vise.

Good luck with your project.

grandpaul wrote:You don't need to remove the sprocket to remove the tranny, or get the gearbox out of the cradle, but you do need to at least remove the bolts holding the rear end of the engine in the tranny cradle, then tip it forward enought to allow clearance for the tranny to rotate to the point where it can come out.

Yup, and as I recall, you need to put the bike on the side stand to get the cradle to align so you can get them out/back in more easily. I may not be remembering this quite right, but this I know: If you're on the center stand, or side stand, and the holes won't align, try the other stand.

You may even need a helper (I did) to slowly ease the bike from side stand to centerstand during the process - my bolts would only line up for reinstallation at some point in the no-man's-land between "on the side stand" and "on the centerstand."

19 teeth is standard in USA and Canada. It's nice for in town but for hiway a 21 is nice. There's nothing wrong with 20.

thanks everybody. especially you grandpaul. i was just to pepboys and picked up the said wrench. think i'll pull the gearbox complete.

need advice on getting the bottom engine/cradle bolt out. mine won't clear the bottom frame rail.

i guess i'll go ahead and do the vernier isolastics and x ring conversions now too. might as well install the reed valve next to the breather too. hell it'd look good w/braided oil lines. jeez, might as well pull the head and have a looksee. why not pull the motor itself out blast and paint him. now's the time for the turnbuckle headsteady too......wait a minute! i think i'll have a washup and several ounces of old no. 7 and come to my senses. for some reason i fear all this snow will melt tommorrow, it'll be 60 degrees and i'll have no bike to throw around the esses. it's only january and the winter madness is upon me!