Condition Transmission Gears

[Ed Northrop]

I will be removing my transmission from my car in the near future as there are some loud noises coming from it. I remove these gears from a spare transmission I have. How would you rate the condition of these gears.
Thanks Ed

[denniskliesen]

What you want to look for is pitting or flaking on the side of the teeth. I noticed in picture #2 there is a spot where it looks to be starting in one spot. Looking at your pictures is hard to tell as you need to look at each tooth on both sides. Look at the inside of your countershaft where the bearing rides for wear and or pitting, also you reverse idler shaft and counter gear shaft. Where is your input shaft?

[J Franklin]

How many miles do you plan on driving each year? I doubt those gears would fail if all the teeth looked as good as the ones I see. They make shafts with seals now so they might fit the bill with all new bearings.

[larrys40]

Ed,
As Dennis noted inspect the gears very well, especially on the "run" side (load). If there is any pitting you may hear it. I know my '30 Tudor had one decent size pit in it and when I first did the car 36 years ago I heard it all the time in 2nd. my daughter toasted the transmission last year (thinking she could drive it)so I finally fixed that issue.

I see there is some sharp edges on the gears where the teeth mesh. top flat side of the gears.. I usually take that edge to the small belt sander to smooth them out if I'm using good original gears. I would use the O-ring reverse idler and cluster gear shafts and seal the case well with rtv and gaskets properly. Don't forget the front bearing retainer as well as the rear. I also like the rear shaft retainer cap ( sold at some of the parts suppliers) as it captures the ends of the shafts and seals it up to keep leaks from occurring there.

Overall I think your gears look decent but need the edge cleanup as I stated. Do not hit the teeth contact area.. just the tops to smooth them from the mesh clang that has occurred over time. Check well for pits and gaulling!
Larry Shepard

[Ed Northrop]

Larry, Dennis
Thanks for the information.
Ed

[Kevin in NJ]

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The Ford gears were broached and will show lines across the face. You can see some across the faces one these gears. Gears that are smooth are worn. These gears look worn some as there are lines, but shiny smoothness too.

The faces where they gears mesh together need to be pointy. Some of these gears look a bit smooth to me. This means it might be a hard shifting transmission. The markings on the one gear indicate it is not original Ford.

How much do you drive? If you just putt putt around at 45 then these will likely work OK, but do not be surprised if it shifts hard.

You also need to measure the sliding shaft. Can you feel a bump at the edge of the gear travels? If so then that shaft is likely not good (you need to check closer). You also need to measure the shaft and the gear for fit. No, I do not believe the put oil on the shaft and see how fast it slides is accurate as suggested by one famous shop manual. Mine had a measured wear of .001" which is fine and failed the test.

My opinion is if you intend to drive the car you may want to take some time and learn what new gears look like on their meshing side and then look closer at yours. You may want to get some or all new gears.

[H. L. Chauvin]

Hi Ed,

1. First .... with only respect for the all so often asked and answered prior Model A Ford transmission questions & answers .... can you spare about $17.00?

2. Second .... if yes .... and if wanting to feel just a little more confident in rebuilding a Model A transmission, in my opinion, just one (1) place to very wisely invest a mere $17.00 is with Bratton's for purchasing "Volume 2, Model A Ford Restoration & Maintenance Handbook", by Paul Moller .... if looking for sound, simple additional advice on restoring Model A transmissions.

3. In Volume 2, Mr. Moller's wrote Chapter 7, "Transmission Changes", e.g., four (4) short pages including seven (7) photographs and two (2) simple drawings indicating Ford's three (3) changes to tops of transmissions, and two (2) changes to the transmission's bottom gear case from 1928 to 1931.

4. Then in Volume 2, Mr. Moller also wrote Chapter 8, "Transmission Repair", e.g., ten (10) pages including twenty-three (23) photographs and two (2) simple drawings indicating judging gears, disassembly and reassembly and other simply written transmission restoration recommendations.

5. In about 1966, (about 51 years ago), Mr. Moller, (just a most humble gentleman like most Model A owners), rebuilt his own 1929 Sport Coupe Model A transmission, took pictures, and drove his car with no problems for over (20)) years, with three (3) trips from home near Chicago, Illinois .... to the West Coast & back .... including a trip to Alaska over the Alcan Highway logging in over 70,000 miles.

6. Mr. Moller's very succinct and highly technical Volume 1 & Volume II, are seldom mentioned on Model A Forums; but they also eloquently describe many of the often heard of other Model A repairs from Model A bumper to bumper in great detail along with meaningful illustrations.

Hope this helps.

[Ed Northrop]

Kevin, Chauvin thanks for the additional information. This past week end I purchased a couple transmission to review the gears to see different wear items one transmission the gears were grind to a sharp edge.

[Railcarmover]

The wear at the top of the tooth,what your calling 'sharp' is why I would shy away from running the cluster and slider gears in your picture. Once a tooth looses its width its on an unstoppable wear cycle..and will have a bunch of gear 'whine'. That being said alot depends on how much you drive the car,if it gets 10k miles in ten years those parts will last.

[SeaSlugs]

Originally Posted by larrys40

Overall I think your gears look decent but need the edge cleanup as I stated. Do not hit the teeth contact area.. just the tops to smooth them from the mesh clang that has occurred over time. Check well for pits and gaulling!
Larry Shepard

i agree. I "cheated" and brought my gears to work and chucked them up in a lathe and got them spinning true then kept making the lightest passes i could (they are hardened obviously) till i could get the faintest of cutting noise across the whole top of the tooth to get rid of the upset.

My word of advice is to replace the trans bearings - all of em and get the sealed shafts and sealed main bearings on one side. Check very carefully the main gear pilot bearing nose for wear and the main sliding gear shaft nose for wear.