replacing ring gear 9 inch flywheel

37pickupproject

37pickupproject

Member
I am working on replacing the ring gear on my flywheel for the 9 inch clutch. I cut and chiseled the old ring off. There is a pretty good lip around the flywheel where the old ring was. I heated the ring gear in the oven at 550 F and it wouldn't slip over the lip.

Is this lip supposed to be there? Freeze the flywheel too?

Thanks for the help.
 
I will have that a shot tomorrow. I was just thinking 550 degrees would do it. Should the ring gear drop right on? Because if it doesn't I don't think I could pound it on without breaking that lip.

Thanks for the reply
 
At the shop I worked at in the 70's, we would heat the new gear with a torch. Going around the perimeter evenly, never getting it "red hot".
It only took a few minutes and all of a sudden the gear could be tapped in place.

If you have a decent machine shop in your area, they will typically do this for you for around $15. It's quite easy...
 
I drive the old one off cold, clean, wire brush the wheel. and lay it on a sturdy table.
Then determine which side has the bevel and lay the ring on three or four welding electrodes bevel side down. Light my acetylene torch with no oxygen, and apply smoke to the ring all around. Then add oxygen to reach a heating flame and slowly heat the ring until the smoke burns off, approximately 400°.Then using heavy leather gloves set the ring on the wheel, bevel side down. It should slip right on. Seat the ring on the wheel with a two pound hammer and drift punch. It will set quickly. Tack weld three or four places, if you need too.
Works good
Lasts long time
Bruce
 
Put the flywheel in the freezer and heat the ring gear on the Barbie (I left mine on about 5-10 minutes if I remember correctly) Pick up the gear with big Channel Locks and it should drop right on.
 
When you say there is a lip, could the old gear have been loose
and wore a groove in the flywheel.

Bob
 
No need to tack weld that really is not a good idea tacking to cast iron.
It is a shrink fit and no need for anything else.Its only a ring gear.

R
 
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51504bat said:
Put the flywheel in the freezer and heat the ring gear on the Barbie (I left mine on about 5-10 minutes if I remember correctly) Pick up the gear with big Channel Locks and it should drop right on.
Click to expand...
Didja throw some steaks on after you did the ring gear? Be a shame to waste a hot barbie. :D
 
I believe the old ring gear was tight as it would turn the engine over as long as the starter had some teeth to dig into. But there is a pretty good lip on it. That's the only thing preventing the ring gear from sliding right on. I wasn't sure if the lip was supposed to be there to hold the ring on.

When I went to remove the old one some of that lip chipped off. I'm out of town for a week but will give it another shot when I get back. Maybe I can post a pic of the lip.

Should the surface be flat all the way to the end of the flywheel? Maybe I'll have to chip that lip off?
 
Put mine on with a torch no need to refrigerate. Don't remember a lip if so and it chips you might consider another flywheel. Especially with any amount of inertia set upon it.
 
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37pickupproject said:
I believe the old ring gear was tight as it would turn the engine over as long as the starter had some teeth to dig into. But there is a pretty good lip on it. That's the only thing preventing the ring gear from sliding right on. I wasn't sure if the lip was supposed to be there to hold the ring on.

When I went to remove the old one some of that lip chipped off. I'm out of town for a week but will give it another shot when I get back. Maybe I can post a pic of the lip.

Should the surface be flat all the way to the end of the flywheel? Maybe I'll have to chip that lip off?
Click to expand...
A lip?
Can you post a picture?
There should be no "lip".
The gear is held on by an interference fit. In other words, the inside diameter of the gear is smaller than the outside diameter of the flywheel.
 
Hopefully this works. At the top of the picture is the "lip" I speak of. You can see where some of it had broken off during removal of the old ring gear.
 

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Ford put the lip there so the ring gear couldn't move in use ---just beating the old gear off can damage the lip, it needs to be drilled/cut and split off
When heating a ring gear only heat the inside so the tips of the teeth don't get hot---you don't want to get it red hot either
 
If you reuse the flywheel it is going to have to be balanced. Even a very small weight difference out at the edge will change the balance.
 
How hot can I get the ring gear? Just didn't seem like it would fit over it. Been out of town so have not tried freezing the flywheel yet. I will do that when I get home. Made the girlfriend send me the photo haha.

I'm rebuilding the engine so the fly wheel will go with the rotating assembly to be balanced.
 
having worked on Jaguars for years i have replaced hundreds of ring gears ,, the way Kube says is the way i have always done it
 
And that is the correct way ^^^^^

What is all the crap about freezing and tack welding "LOL". :)
Heat it up and it will drop on.And shrink back to where it should be.

R
 
Ronnie said:
And that is the correct way ^^^^^

What is all the crap about freezing and tack welding "LOL". :)
Heat it up and it will drop on.And shrink back to where it should be.

R
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Bingo! I can however, understand apprehension in a person having not done this before.
However, the "newbie" can rest assured it is a s simple operation. No freezing is necessary. And welding? Why would anyone need to weld the gear on?

Just get the old gear off any way you like. Grind away that lip (something I have never seen) and place your new gear atop the flywheel. Using an oxy / acetylene torch, heat the gear up evenly. No need to get red hot - not even close. All of a sudden you'll see the gear drop in to place. Tap it lightly with a hemmer (brass or lead ) to make certain it is seated and let it cool. All done.
 
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