Speedo Drive Gear

[herwiggy]

I plan on running a speedo/dash on the '49FL I'm building. Of course there wasn't a speedo drive gear on the counter shaft.




Had to tear the tranny apart again. The new speedo drive gear I got slipped right onto the countershaft. I spent hours last night searching what needs to be done to keep this thing on. Some people are suggesting tack welding it on......others using green loctite........Bruce Palmer suggests staking/peening it on.

Anyone have an opinion on it?

Right now I'm leaning towards chucking it up in a lathe (to check runout) and tacking it with the tig in multiple places......checking runout as I go.

[Robert Luland]

The originals were staked on the sides to hold them in place. Since you most likely don't have a $200 grand press with a $60K custom die? Once the ring is pressed off you will never get it to fit tight again. The Chines crap is even more unforgiving. You don't have to worry about centering the ring since it is the same width as the boss your putting it on. This is how I do it. And no, your not going to compromise the heat treating of the gear. You only need a couple of tacks on each side but move quick to avoid weld shrinkage. The mini-clamps are a most when doing this. Bob L

[herwiggy]

The originals were staked on the sides to hold them in place. Since you most likely don't have a $200 grand press with a $60K custom die? Once the ring is pressed off you will never get it to fit tight again. The Chines crap is even more unforgiving. You don't have to worry about centering the ring since it is the same width as the boss your putting it on. This is how I do it. And no, your not going to compromise the heat treating of the gear. You only need a couple of tacks on each side but move quick to avoid weld shrinkage. The mini-clamps are a most when doing this. Bob L

Thanks Bob,

Did you tack it on both sides? I'm assuming by "you don't have to worry about centering the ring" you meant that it is not necessary to check runout? This seems almost too easy. Things NEVER end up being too easy for me.

[T. Cotten]

Mark!

I agree with Bob, of course, about reproductions: They can be too tight as well as too loose.
But I have easily pressed OEM worms off and on with no issues whatsoever.
Finding one will save much grief, as well as avoiding distortion, or ruining the hardening with weld tacks.
They can be quite cheap when found upon a trashed clustergear.

Accurate alignment prevents side thrusts that would move the gear, as well as prevent wear to either gear. If it is "true", it will stay 'true'.

Alignment is best achieved between centers as shown in the attachment.
Please avoid tapping upon them near the ends of the gear teeth, as they are quite brittle.

....Cotten

[exeric]

Is there a source for the mating fiber gear?

[Robert Luland]

Avoid the nut above (Not Eric, the one above him). Technically and for all intensive purposes. You could get away with just a tack on each side. There is no load on that gear. You just want make sure it doesn't wander after you put your box back together. There would never be a reason to put a dial indicator on it unless you want to waste untold amounts of your time. The c clamps will hold it dead on center upon it's perch. Bob L

[Robert Luland]

Eric, no. I have a lot of speedo stem gears that are fiber but I've never seen the main gear made that way. Bob L

[exeric]

I was asking about the little drive gear splined onto the speedo stem. If you have them Bob, I'll be ordering one from you. Thanks.

[T. Cotten]

Avoid the nut above (Not Eric, the one above him). Technically and for all intensive purposes. You could get away with just a tack on each side. There is no load on that gear. You just want make sure it doesn't wander after you put your box back together. There would never be a reason to put a dial indicator on it unless you want to waste untold amounts of your time. The c clamps will hold it dead on center upon it's perch. Bob L

Name-calling, Bob?

If "there is no load on that gear", then it doesn't need to be attacked with welds either.
The only way to be certain that there is no load, is to be certain that it spins true.

Precision rules, hacking drools.

....Cotten

[Robert Luland]

Tom, go to sleep.

[T. Cotten]

Folks,

You will find that both worm and drive gears on '49 BTs were steel.

45" drives were phenolic, or "fiber".

....Cotten