Transmission Rebuild by Kohnke Rebabbitting
Posted: Tue Mar 12, 2019 12:21 pm
This is a great post from the old forum I think would interest those that have not seen it.
By Kohnke Rebabbitting on Saturday, July 20, 2013 - 07:01 pm:
The Brake drum was shot, so we ordered one from J&M Machine, Oh, what a Beauty, in every way.
I started taking pictures today, and will add more as I progress, as if I wait, it will take a long time to get them all listed.
This is a Jig I made, to align Ream the Tail shaft bushing, as out of Ford Service.
Align Reaming Tail Shaft Bushing
Triple Gear Reamer, Wilson Benches coming. First one is a starter and Gen. table, I have Two.
Showing Reamer Finish.
Parts Ready to Machine
Pictures Showing Dial points
Showing center Point that was making the shaft off center, I cleaned it up, and it centered
Hose clamp to hold the fingers back
Centering brake drum in 4 Jaw
Brake drum, Tail Shaft, and also Main shaft now in perfect Alginment
Got the Triple Gear pins in the mail today, and have to polish out .000-50 thousandths on the bearing part of the pin.
I will have to take .001 thousandths off the part that press's into the flywheel.
That will leave a .003 thousandths press on the pins, and a .003 clearance on the Gear Bushing.
Polishing Triple Gear Pins to size.
The 1.560 is how far back I cut the tail shaft for the Ball cap, no matter if it is ball bearing, or babbitt. This motor will get babbitt.
I will polish out the tail shaft tomorrow, and cut the ball cap.
By the way, that clamp and switch is my automatic shut off switch.
Polished, before polishing
Can still see the lines after the 1500 grit, but can't with the finger nail.
Aligning the ball cap at the only place that comes close to the center every time.
Ruffed out babbitt at high speed, .020 left to go.
If you want something that gets right to the 1/10 of a thousandths every time, these are what will do it. They are call inside Mic's, or also Post Mic's.
Putting in the oil groove.
Made for pressing out the pins, but normally I just take a big hammer and knock them out.
I oil the pins. I use a dead blow to tap them in.
I use 1/2 of a Model T wrist pin to push the pin to level.
I use 1/4 inch coarse X 2" bolts and tap the flywheel.
My boy made this to use flywheels on.
It goes up, down, and turns so you can work on the Magnets, or what I am doing.
I hold a big hammer under the bolt to take the stress of the threads when peening.
Small taps, no big hits.
Oil the inside of the gear and shaft
A couple of things here.
After you press on the driven gear, it just about always makes the brake drum bushing go smaller, and from the two keys pushing in on the bushing that you should always run the reamer through again to size the hole where it was.
The other thing is the clutch spring pin should be cleaned up so the pin can be placed by hand, instead of having to pound it in.
Band Building
We media blast, "Black Diamond", no dirt, make sure there is nothing caught under the end that is riveted on. clean, clean, clean.
As they come out of the box.
I mark an inch.
I use a metal shears to cut the 1 inch off.
Cut off.
What I use to seal the ends from raveling, way better then what was on them out of the box.
I spray on a slick paper, so it don't soak in so fast, or wax paper.
3 Pieces cut in 1/2.
This is two coats.
K.R. Wilson rivet machine.
Check to make sure bands match drums.
Rivet seated on the inside.
The ends of the bands out further then the band ears, so they don't gouge the drum surface.
Transmission assembly:
By Kohnke Rebabbitting on Sunday, July 21, 2013 - 03:40 pm:
I always check the drums with expanding mandrels to see where the out sides are with the center, and that is with out bushings.
The first time I knew the center was right, as I check, and recheck, and found out with the mandrel, that the drum was sprung a little, and that is a waste of time, and bushings.
If the drum is sprung, which isn't too often, but happens, I pitch the drum.
The drums that the out sides were cut, or out of round with the center, they do go in a 4 Jaw, and get the bushing shaft with gear centered and bored to within a .001
Then they go in the Wilson jig and centered on the reamer taper, locked down, and the last .001 is reamed with the hole, and Jig.
The out side band area does not touch, or do you want it to.
I have had I think 3 re-rebuilds that I had to do this way, other wise, its normal.
Then the out side is trued again, and no I don't have to take off a 1/4 inch.
Thanks Herm.
By Kohnke Rebabbitting on Sunday, July 21, 2013 - 05:50 pm:
I have almost 3 sets of reamers. Two sets were were N.O.S..
So far I have used both sets, and sharpened both sets once when it gets time.
Counting just transmissions, I should have done about 350 to 400.
I don't use them dry, as I use cutting oil on the bushings.
You have to check the reamer under a big Mag. Glass, to see if there is any reflection of light of the edge that cuts. If there is, that's the time to sharpen, or you can ruin the reamer.
When you sharpen a reamer, they only sharpen the taper part, if they have to sharpen the side, they some times can do it once, a very little, or the hole size gets smaller.
While they would still bore straight, you would have to finish with a hone, or a different reamer of some kind.
By Kohnke Rebabbitting on Tuesday, July 23, 2013 - 11:24 pm:
The first drum had .018 thousandths taken off.
The second one, .011-50 to .012.
I would have taken more if needed.
To just polish a pitted, wore, and warped drum O.D. is not rebuilding.
High and low spots on drums give bad band surface. It seamed important enough when they were new.
I have always turned the drums, and would never put a Transmission together with out it.
They were rust pitted, and the drums are just about always not true from band wear.
Trueing them makes them round to the center, and a 100% band contact.
To me, with out Trueing the drums would be like putting on New brake shoes, and not true the drums, that makes every thing New again.
The only drum I didn't turn was J&M Machines New brake drum, as it dialed Zero.
By Andre Valkenaers on Thursday, July 25, 2013 - 02:06 am:
Herm, Why do you use only one bushing on the brake drum??
Thanks Herm
Andre
Belgium
By Kohnke Rebabbitting on Thursday, July 25, 2013 - 01:12 pm:
Andre, I leave them out because they are not needed. Ford left them out in late 1925, and later.
The only way the oil gets into the Brake Drum bushings is the hole in the Drum shaft, or what can get in the ends of the bushings.
With the inside bushing left out, that whole cavity from the Driven Gear, to the Drive Plate bushing is oiled, and acts as an oil well.
It is also harder to Align 3 bearings, rather than two.
With 2 Bearings you can bore them separate, as long as they are straight with the housings, but with 3 or more, they have to be align Bored, or align reamed.
By Chris Brancaccio - Calgary Alberta on Thursday, July 25, 2013 - 02:32 pm:
Herm, do you balance the drums?
How is the balance on the new J&M drum?
By Kohnke Rebabbitting on Thursday, July 25, 2013 - 03:33 pm:
Chris, We have the drums Balanced if the owner wants it.
But we always balance the Flywheel.
We have had only one Balanced from J&M Machine. It was off a little, but so are the Originals, and a lot more. They sure have the Originals beat by far. I don't think you could cast a piece like that and get any kind of balance.
Every thing is balanced from the wheels on out modern car to air craft parts.
By Stephen D Heatherly on Thursday, July 25, 2013 - 10:07 pm:
Herm, do you always replace all the bushings or just the worn out ones? I have heard several times that replacing the bushings makes for a noisy transmission but, I would think as long as everything was done right there would be no problem.
Stephen
By Kohnke Rebabbitting on Friday, July 26, 2013 - 12:42 am:
Stephen, I have never taken a Transmission apart, that was good enough to just clean up, and put back together, for my own, or a customer.
The transmissions will run wore out, if not to bad, as will the rest of the motor.
The problem comes in when the bushings wear to much, and then start taking out the gears on a drum, or triple gear that could have been saved.
If the triple gears are left go to long, with .004 thousandths, on up, and as all triple gear pressure is to the outside, the gear will run tipped on the shaft, and the teeth will eat into the flywheel, and ruin the gear surface, and or the flywheel.
As far as the noise, I have never heard one any different then another, outside of the ones that need fixed.
If you have grinding, scraping, knocking, ect., something was over looked.
Many transmissions are left with the old triple gear pins. A typical triple gear pin is .002 thousandths out of round, and it is always on the high pressure side on the gear. So, if you fit the new bushing with .003 to the largest diameter, with wear of .002 at its lowest, now the clearance is .005, and the triple gear has no choice, but to run cocked.
So, when the triple gear runs cocked, it will tear up the teeth on the driven gear, and the drums.
The last thing, when I get time, I will take some Mic readings on my N.O.S. drums and triple gears, as they are factory reamed, and that should put to rest the difference of opinion on what the clearances should be, as these will be Ford factory Spec's.
By Andre Valkenaers on Saturday, August 03, 2013 - 01:36 am:
I just Wonder:
Why do you cut the band lining in half and are you leaving a gap in the middle of the lining? Is this for a better cooling and oiling of the bands??
What is the red stuff you add on the bands at each end??
This real a great writing and should be saved in a manuel.
Thanks
Andre
Belgium
By Kohnke Rebabbitting on Saturday, August 03, 2013 - 01:03 pm:
Andre, I read about the band lining method in a Dykes automotive book when I was a kid. It made sense, so I have always done it that way.
It leaves a one inch gap at the bottom for oiling.
With out the stiffness in that missing band area, the band is left to be able to flex more so all the band will contact at all the band, not just some areas.
The bands as they come out of the box do not have enough goop on some ends to keep them from raveling.
There is already a picture of this, but this is red electrical insulation paint which I get at an electric motor shop.
Thanks Herm.
Jason Walters
By Kohnke Rebabbitting on Saturday, July 20, 2013 - 07:01 pm:
The Brake drum was shot, so we ordered one from J&M Machine, Oh, what a Beauty, in every way.
I started taking pictures today, and will add more as I progress, as if I wait, it will take a long time to get them all listed.
This is a Jig I made, to align Ream the Tail shaft bushing, as out of Ford Service.
Align Reaming Tail Shaft Bushing
Triple Gear Reamer, Wilson Benches coming. First one is a starter and Gen. table, I have Two.
Showing Reamer Finish.
Parts Ready to Machine
Pictures Showing Dial points
Showing center Point that was making the shaft off center, I cleaned it up, and it centered
Hose clamp to hold the fingers back
Centering brake drum in 4 Jaw
Brake drum, Tail Shaft, and also Main shaft now in perfect Alginment
Got the Triple Gear pins in the mail today, and have to polish out .000-50 thousandths on the bearing part of the pin.
I will have to take .001 thousandths off the part that press's into the flywheel.
That will leave a .003 thousandths press on the pins, and a .003 clearance on the Gear Bushing.
Polishing Triple Gear Pins to size.
The 1.560 is how far back I cut the tail shaft for the Ball cap, no matter if it is ball bearing, or babbitt. This motor will get babbitt.
I will polish out the tail shaft tomorrow, and cut the ball cap.
By the way, that clamp and switch is my automatic shut off switch.
Polished, before polishing
Can still see the lines after the 1500 grit, but can't with the finger nail.
Aligning the ball cap at the only place that comes close to the center every time.
Ruffed out babbitt at high speed, .020 left to go.
If you want something that gets right to the 1/10 of a thousandths every time, these are what will do it. They are call inside Mic's, or also Post Mic's.
Putting in the oil groove.
Made for pressing out the pins, but normally I just take a big hammer and knock them out.
I oil the pins. I use a dead blow to tap them in.
I use 1/2 of a Model T wrist pin to push the pin to level.
I use 1/4 inch coarse X 2" bolts and tap the flywheel.
My boy made this to use flywheels on.
It goes up, down, and turns so you can work on the Magnets, or what I am doing.
I hold a big hammer under the bolt to take the stress of the threads when peening.
Small taps, no big hits.
Oil the inside of the gear and shaft
A couple of things here.
After you press on the driven gear, it just about always makes the brake drum bushing go smaller, and from the two keys pushing in on the bushing that you should always run the reamer through again to size the hole where it was.
The other thing is the clutch spring pin should be cleaned up so the pin can be placed by hand, instead of having to pound it in.
Band Building
We media blast, "Black Diamond", no dirt, make sure there is nothing caught under the end that is riveted on. clean, clean, clean.
As they come out of the box.
I mark an inch.
I use a metal shears to cut the 1 inch off.
Cut off.
What I use to seal the ends from raveling, way better then what was on them out of the box.
I spray on a slick paper, so it don't soak in so fast, or wax paper.
3 Pieces cut in 1/2.
This is two coats.
K.R. Wilson rivet machine.
Check to make sure bands match drums.
Rivet seated on the inside.
The ends of the bands out further then the band ears, so they don't gouge the drum surface.
Transmission assembly:
By Kohnke Rebabbitting on Sunday, July 21, 2013 - 03:40 pm:
I always check the drums with expanding mandrels to see where the out sides are with the center, and that is with out bushings.
The first time I knew the center was right, as I check, and recheck, and found out with the mandrel, that the drum was sprung a little, and that is a waste of time, and bushings.
If the drum is sprung, which isn't too often, but happens, I pitch the drum.
The drums that the out sides were cut, or out of round with the center, they do go in a 4 Jaw, and get the bushing shaft with gear centered and bored to within a .001
Then they go in the Wilson jig and centered on the reamer taper, locked down, and the last .001 is reamed with the hole, and Jig.
The out side band area does not touch, or do you want it to.
I have had I think 3 re-rebuilds that I had to do this way, other wise, its normal.
Then the out side is trued again, and no I don't have to take off a 1/4 inch.
Thanks Herm.
By Kohnke Rebabbitting on Sunday, July 21, 2013 - 05:50 pm:
I have almost 3 sets of reamers. Two sets were were N.O.S..
So far I have used both sets, and sharpened both sets once when it gets time.
Counting just transmissions, I should have done about 350 to 400.
I don't use them dry, as I use cutting oil on the bushings.
You have to check the reamer under a big Mag. Glass, to see if there is any reflection of light of the edge that cuts. If there is, that's the time to sharpen, or you can ruin the reamer.
When you sharpen a reamer, they only sharpen the taper part, if they have to sharpen the side, they some times can do it once, a very little, or the hole size gets smaller.
While they would still bore straight, you would have to finish with a hone, or a different reamer of some kind.
By Kohnke Rebabbitting on Tuesday, July 23, 2013 - 11:24 pm:
The first drum had .018 thousandths taken off.
The second one, .011-50 to .012.
I would have taken more if needed.
To just polish a pitted, wore, and warped drum O.D. is not rebuilding.
High and low spots on drums give bad band surface. It seamed important enough when they were new.
I have always turned the drums, and would never put a Transmission together with out it.
They were rust pitted, and the drums are just about always not true from band wear.
Trueing them makes them round to the center, and a 100% band contact.
To me, with out Trueing the drums would be like putting on New brake shoes, and not true the drums, that makes every thing New again.
The only drum I didn't turn was J&M Machines New brake drum, as it dialed Zero.
By Andre Valkenaers on Thursday, July 25, 2013 - 02:06 am:
Herm, Why do you use only one bushing on the brake drum??
Thanks Herm
Andre
Belgium
By Kohnke Rebabbitting on Thursday, July 25, 2013 - 01:12 pm:
Andre, I leave them out because they are not needed. Ford left them out in late 1925, and later.
The only way the oil gets into the Brake Drum bushings is the hole in the Drum shaft, or what can get in the ends of the bushings.
With the inside bushing left out, that whole cavity from the Driven Gear, to the Drive Plate bushing is oiled, and acts as an oil well.
It is also harder to Align 3 bearings, rather than two.
With 2 Bearings you can bore them separate, as long as they are straight with the housings, but with 3 or more, they have to be align Bored, or align reamed.
By Chris Brancaccio - Calgary Alberta on Thursday, July 25, 2013 - 02:32 pm:
Herm, do you balance the drums?
How is the balance on the new J&M drum?
By Kohnke Rebabbitting on Thursday, July 25, 2013 - 03:33 pm:
Chris, We have the drums Balanced if the owner wants it.
But we always balance the Flywheel.
We have had only one Balanced from J&M Machine. It was off a little, but so are the Originals, and a lot more. They sure have the Originals beat by far. I don't think you could cast a piece like that and get any kind of balance.
Every thing is balanced from the wheels on out modern car to air craft parts.
By Stephen D Heatherly on Thursday, July 25, 2013 - 10:07 pm:
Herm, do you always replace all the bushings or just the worn out ones? I have heard several times that replacing the bushings makes for a noisy transmission but, I would think as long as everything was done right there would be no problem.
Stephen
By Kohnke Rebabbitting on Friday, July 26, 2013 - 12:42 am:
Stephen, I have never taken a Transmission apart, that was good enough to just clean up, and put back together, for my own, or a customer.
The transmissions will run wore out, if not to bad, as will the rest of the motor.
The problem comes in when the bushings wear to much, and then start taking out the gears on a drum, or triple gear that could have been saved.
If the triple gears are left go to long, with .004 thousandths, on up, and as all triple gear pressure is to the outside, the gear will run tipped on the shaft, and the teeth will eat into the flywheel, and ruin the gear surface, and or the flywheel.
As far as the noise, I have never heard one any different then another, outside of the ones that need fixed.
If you have grinding, scraping, knocking, ect., something was over looked.
Many transmissions are left with the old triple gear pins. A typical triple gear pin is .002 thousandths out of round, and it is always on the high pressure side on the gear. So, if you fit the new bushing with .003 to the largest diameter, with wear of .002 at its lowest, now the clearance is .005, and the triple gear has no choice, but to run cocked.
So, when the triple gear runs cocked, it will tear up the teeth on the driven gear, and the drums.
The last thing, when I get time, I will take some Mic readings on my N.O.S. drums and triple gears, as they are factory reamed, and that should put to rest the difference of opinion on what the clearances should be, as these will be Ford factory Spec's.
By Andre Valkenaers on Saturday, August 03, 2013 - 01:36 am:
I just Wonder:
Why do you cut the band lining in half and are you leaving a gap in the middle of the lining? Is this for a better cooling and oiling of the bands??
What is the red stuff you add on the bands at each end??
This real a great writing and should be saved in a manuel.
Thanks
Andre
Belgium
By Kohnke Rebabbitting on Saturday, August 03, 2013 - 01:03 pm:
Andre, I read about the band lining method in a Dykes automotive book when I was a kid. It made sense, so I have always done it that way.
It leaves a one inch gap at the bottom for oiling.
With out the stiffness in that missing band area, the band is left to be able to flex more so all the band will contact at all the band, not just some areas.
The bands as they come out of the box do not have enough goop on some ends to keep them from raveling.
There is already a picture of this, but this is red electrical insulation paint which I get at an electric motor shop.
Thanks Herm.
Jason Walters