MTFCA Forum

I got this ring gear from Chaffin, is it okay to use?

I would not.
The drive side of the teeth surface is breaking down. Metal is coming off. Heat treat is gone.
If some one offered this gear to me for $5, I would pass.

I have seen a lot worse working well and most times very quiet. Do you have the matching Pinion? For the amount of miles your most likely to travel and if you infact have the Pinion I would reuse it. I agree that’s it is breaking down but those defects actually hold oil! Sometimes a worn genuine Ford part is superior to reproductions and what you have may give you years of service. Just my opinion
Alan In Western Australia

If the heat treatment is gone, can you re-heat treat to make it serviceable again? I have tempered parts by heating cherry red then quenching in oil? The color of the heated metal would determine the amount of temper so it is strong but not too brittle, but I am not experienced enough to advise on the proper color prior to quenching. Perhaps someone here can advise. It would be ashame to discard it if it can be salvaged and used. Jim Patrick

I doubt the pinion I have was used with this ring gear

I have taken much worse out of rear ends that the ring & pinion where not a failure. I have not installed one in that condition to find
out but would like to hear from some one that has. If you think about it we buy a lot of used parts from people that decided to buy new
and sell what they had. I have not purchased a single part from Chaffins that I was unhappy with. In fact I have purchased used parts
from Glen & Mark that where better than some new parts from other venders. The guy that got me into model T's would probably
consider that a good ring gear and not think twice about using it but he passed some time ago so I can't consult him.
Craig.

Risk & reward....
How much will you save if you use it and it outlasts you? (the cost of a new ring gear)
Then excluding the cost of a new ring gear.
How much will it cost you in time & money to rebuild the rear axle if it fails or the ensuing noise is annoying.

Like they say
There's never enough time (money) to do it right the first time, but there's always enough time (money) to do it over.

I have seen worse run fine for many years to come.

Chaffin's has a pretty good reputation as well as knowledge. Can't believe they would send off anything questionable.

When I look at ring and pinion gears from rear ends that have never been disassembled I typically see much worse.
They take a lot of abuse and still run fine. In fact the worn ones run quieter than the newly rebuilt ones.
You might experience some rear end growl because you are using mismatched parts, but there is no doubt in my mind they will function fine.
As a pointer, set them up for at least 15 thou lash. Chaffin once told me Ford set them at 25. Whether that's true or not, they run quieter at a greater lash than is usually recommended.

There are worse ring gears running in T’s that have been running for a good while. It depends I guess how much of a perfectionist a person is if you wouldn’t want to use it. But that’s my opinion. I doubt it would fail anytime soon if you wanted to use it.

The ring gear in my coupe is in pretty much exactly the same shape. The gear ran perfectly fine and quiet for over 10k miles on countless tours including the covered bridge tour twice. I removed my ruckstell from the car to install it in my centerdoor. The gear is still serviceable and will be used in the stock rear end that's going back in the car.

Stephen

It looks bad to me, but evidently a number of people have had good results with gears in similar condition. It looks like the major wear is near the outer diameter. Since you probably don't have the original pinion gear, or the settings it was running at, you might get better results if you set it up to have the tooth contact area more nearly centered. I'd keep speeds and loads down for a hundred miles or so to give parts a change to wear in. A heavy gear oil might be advisable. You could also consult with Mr Chaffin for advice. I don't know what noise level is normal for a T axle in good condition. I don't think they were ever as quiet as a spiral bevel.

This is my first Model T and have only driven for about an hour total, when I bought this gear I told Chaffin's its only an occasional driver definitely not interested in touring, Chaffin said this gear would work fine and I have no reason to doubt that, he comes highly recommended on the forums, just that being such a newbie I thought I'd check, I just never want to touch the rear axle again.
I blued up a tooth and stoned it, this is what it looks like.
I think I'll post a wanted add for a better gear, just for piece of mind and I don't know any better of whats good and whats not.

For the occasional putt putt for ice cream or a parade, it will probably provide good service.

If you wanted to do significant touring, I would pass on it. My cars get 2,000+ miles a year and if that gear was mine, I would put it in the pitch it bucket.

Chaffins provided a gear that should suit your stated purpose and I'm sure for fewer $$ than a new gear. Should be a good deal in your world.

There are different gear ratios. You need to find a matched set between the pinion gear and the ring gear. Best is either new gears or a set which has been together before so the wear pattern meshes. If you have just one point of mesh, it will put a strain on the gear leading to breaking off teeth. Get the booklet on "Rear Axle" from Chaffins or from the club. This will give you complete instructions for the amature mechanic on how to check everything and set the proper clearances.
Norm

bmklawt wrote: ↑

Fri Nov 18, 2022 3:59 pm

This is my first Model T and have only driven for about an hour total, when I bought this gear I told Chaffin's its only an occasional driver definitely not interested in touring, Chaffin said this gear would work fine and I have no reason to doubt that, he comes highly recommended on the forums, just that being such a newbie I thought I'd check, I just never want to touch the rear axle again.
I blued up a tooth and stoned it, this is what it looks like.
I think I'll post a wanted add for a better gear, just for piece of mind and I don't know any better of whats good and whats not.

I think it would be fine for what you want to do.

It will last as long as you own your car.

The main concern with those gears is broken or badly chipped teeth and those teeth are all there.

While there may be a hum associated with the higher speeds, it would not wear beyond use in 25,000 miles.

Chaffins would not sell a part that was not any good or even marginal, and they have certainly been in busies long enough to know a bad part.