MTFCA Forum

I want to replace the aluminum timing with an original steel one.

Is it as simple and pulling off the aluminum gear and pushing on the steel gear?

Is the timing gear "pressed" on? That would make swapping the gear MUCH more difficult.

am curious as to why you'd want to do this?

not a particularly insurmountable job, but can get involved if things don't go your way...what is the effort vs benefit analysis of this job??

The aluminum timing gear is super noisy to the point that during a 2 day T run last week folks were asking me why my engine was so noisy.
It is obnoxiously loud which is why I want to change it.

Does your car have a generator? I suggest that you replace both gears as a set. Timing gears depend on good cam bearings and main bearings to run correctly. Generator drive gear clearance can be adjusted, if necessary.

Did you find a stash of NOS gears? If not, why would you put on a used/worn gear? Are you aware of the gear teeth tolerance/fit? Its real tight, like .002" for iron
If you dont like the aluminum gear, is it because its noisy or clangy due to wear or the necessary looser fit due to expansion?
The best answer, IMHO, would be to get a Dan Mceachern bronze gear. Accurately cut to new specs & low expansion allowing for a tighter gear mesh. .004" for bronze. Available in over & under sizes. (Follows Dan's recommendation.)

To answer your question, the job is rather simple.(see your service manual) You need to pull the radiator, crank pulley & timing cover.
You need a good tool to fit the gear nut. There are a variety, but it must fit tight with no slip to bugger the thin edges.
You may find your crank gear has a lot of wear also. If that needs replacing, the pan has to be separated from the motor which realistically means a motor removal.

Do you know if your engine has the original type felt/rope front seal or a modern
metal/rubber lip seal? Removing the front plate presents more challenges with the modern seal.
Remember to center your front plate with a centering tool when reassembling.
Harry

Wish I'd heard it running last weekend. I remember you mentioning it. Remove the generator and look at the cam gear to verify extreme gear wear - how long ago did I replace it ?

I think you can see enough of the gear looking thru the oil filler hole on generator motors.

Be sure to align the timing marks on the gears! If you just put the gear on without that alignment, the engine won't run. My first car was a Model A and it has similar gears to a T. I didn't know anything about aligning the gears and it wouldn't start even coasting down a hill. Just good thing there was an auto garage downhill from me and I parked in front. The mechanic came out to see me and he told me how to do it. I did so right at the curb in front of his shop and it started right up. Then he asked me if I wanted a job. I worked for him several years after school and summers.
Norm

Can't see much from the oil fill access, John K. - just a bit of the front which doesn't show any gear wear - I believe you need to see the rear thus removing the generator gives a wide view.

I have an aluminum timing gear in my 21 Touring. When I had the short block rebuilt I was told it could be a little noisy at first and I really didn’t notice it being overly loud. I put the rest of the engine together myself and did install a new generator gear. If it’s louder than it’s supposed to be I also have a brass gear in another T and it’s not louder than that car. This is my assessment of my cars.

You’ll need to make sure the timing gear cover is properly a-lined with the cam when you reinstall or your timer won’t run true

I’ve been running nylon cam gears for about 15 years now. Very quiet. No issues even when running an alternator. Some others have had issues.
Tom

Aluminum cam gears are not all the same. Different alloys. Some are/were relatively soft & anodized a color. There was some in 6061 t6 (good)
Aluminum gears require more clearance depending on the alloy. A long ways back I tested one before an install. Heated in boiling water. The diameter grew .025" So clearance was set @ .012, as I recall. Gear was a bit noisy until the motor got up to temperature. I have been using Dan M. bronze gears since.

I replaced a fiber gear with aluminum two years ago. I could hear the gear, strangely, during deceleration for the first few drives. It has not made the same noise since then. I hear no detectable gear noise. I assume that was a break-in period and I may have had my clearance a little tight.

RajoRacer wrote: ↑

Mon Sep 26, 2022 12:27 pm

Wish I'd heard it running last weekend. I remember you mentioning it. Remove the generator and look at the cam gear to verify extreme gear wear - how long ago did I replace it ?

It was the 2nd engine you did for me but it has been 10 years since you replaced it. The longer I run it the more I hate it!

TXGOAT2 wrote: ↑

Mon Sep 26, 2022 11:21 am

Does your car have a generator? I suggest that you replace both gears as a set. Timing gears depend on good cam bearings and main bearings to run correctly. Generator drive gear clearance can be adjusted, if necessary.

Running an alternator now.