1913 Diff ratio, Noisey reverse & wont run on mag?

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Model T Ford Forum: Forum 2015: 1913 Diff ratio, Noisey reverse & wont run on mag?
Top of pagePrevious messageNext messageBottom of page Link to this message  By Kevin Weeds on Monday, May 11, 2015 - 03:00 am:

Today worked on a friends fresh 1913 import from USA got it started for the first time.
Motor runs sweet, didn't over heat and no visible smoking. Really nice when cruising.

I would like your advice about the following -

1. Diff ratio different in 1913?
2. Whats an easy way to test mag output?
3. What to look for under trans cover re noisy reverse?

The car must have a different diff ratio than my 27 as I could drive around the street not bad in 1st gear (my 1st is only good to get rolling and too slow to drive more than a short distance) plus when changing into top gear its just on the point of being too big a step & takes ages to pull away again, 30 odd mph and the engine is only ticking over doing about 1,000rpm it seemed. Definitely geared different to mine.
Plus it wont run on Mag, its the same as turning the key to off?
And reverse is very noisy, other gears fine. My reverse doesnt make this much noise?

Note - This was my first try of Rocky mountain brakes and I really like them, much more positive than my trans brake.
Thanks Guys


Top of pagePrevious messageNext messageBottom of page Link to this message  By Wayne Sheldon, Grass Valley, CA on Monday, May 11, 2015 - 05:39 am:

Just the usual warning about the RM brakes. They work great forward, but in reverse, they don't work well at all. This is especially bad when stopping on a hill, whether planned or not.
Most people seem to suggest a careful setup of the planetary brake to assist the RMs. Personally, I don't like that idea. If anything causes the adjustments to change? (Like wear?) You can wind up in a surprise bad situation.
I prefer good cast iron lined brakes inside the small drums operated by the hand brake. Properly set up, they alone will stop and hold a model T under most usual conditions. If properly set up and properly maintained, the cast iron lined inside brakes are an almost totally independent system that can be used in emergencies and on hills.
The preceding was and is my opinion. Others disagree with me. You should consider those opinions as well.

The gear ratio sounds like a high ratio, probably three to one. 3.63 to one was the standard throughout model T production. Ford did offer a lower ratio (4 to 1) in some parts of the USA because of the hilly terrain.
After-market suppliers offered a variety of ratios to fit the Ford rear axle. Three to one sets were offered by Ruckstell and other gear companies and were fairly popular. They were even more popular in the '60s and '70s when model Ts were becoming sought-after antique automobiles. Reproduction sets have been available continuously for about fifty years.
Three to one gears are especially popular on runabouts due to the lighter weight of the body and the fact that you can't load it up with five adults. With the light weight, many people still like them for higher speeds and less engine wear. Then again, you are about twice as likely to break a crankshaft with 3 to 1 gears.

The noisy reverse could be a problem. Hopefully, it is just a mismatched gear, and could quiet down as it wears in. This is actually a common problem in model Ts. Some of them never get quiet, but work okay for years. Other times, it can be something serious like really bad gears, worn or seized bushings, or any of a dozen other bad things.
A good visual inspection through the bands' cover is always a good start. Crank the engine over, press the pedals hard, slam the brake handle forward and backward to work the clutch. Look for anything in the drums or gears moving around in any way that seems wrong. Rotate the engine till one of the triple-gears is near the top of the flywheel. Being careful, reach with your fingers and try to move that gear forward and backward or turn it, shake it etc. Pull fingers out of the way, rotate engine to the next triple-gear and check it also, then the third one. You should not be able to move those triple gears much with your fingers. But if a bushing has gone bad (or a couple other odd bad things), they may move quite a bit.
I had one once that moved too much, and when I pulled the engine apart, two of the triple-gear pins fell out of the flywheel before I even got it all apart. The really funny part about it was that that was one of the quietest and smoothest model T transmissions I ever drove.

Good luck! Beautiful car!
Drive carefully, and enjoy, W2


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Georgetown TX on Monday, May 11, 2015 - 07:53 am:

Kevin,

We measure the health of a magneto in the car by checking voltage output under load.

I call this the Regan - Patterson Memorial Magneto test after its inventors.

To check the magneto voltage one connects a #1156 automotive bulb between the magneto post and ground. This provides a load so the magneto reading is known to be stable.

An analog (NOT digital) AC voltmeter is then connected to the same points. With the engine running at idle you should see maybe 6 volts at idle. With the throttle advanced to high engine speed a good magneto will read 20 - 30 volts. The light bulb will burn out rapidly if this is sustained.

More relevant information is here:
http://www.mtfca.com/discus/messages/80257/96176.html


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kevin Weeds on Monday, May 11, 2015 - 08:19 am:

Wayne, thanks for your detailed feedback. The owner wont be going far at this stage and I think the Rocky's work with the trans break. Havent got any hills in town but there is a few once out of town. The Rocky's felt great going forward. Are you saying if you stop on a hill and roll backwards they can fail or they will fail? I guess the trick would be stop while still going forward and hold. Will pass this info on.
Noisy reverse could settle down as the car was restored about 20 yrs ago then sat on jacks in a VW dealership on display and never driven. It had a new fuel tank and Carby fitted prior to sale so potentially has had little driving, lets hope it will settle.
Maybe the diff is a 3-1, no room carry a load in the boot or more than 2 people so someone may have seeked higher top speed.

Royce - Sounds a plan to test the mag, might try tomorrow. Thanks


Top of pagePrevious messageNext messageBottom of page Link to this message  By Richard Gould, Folsom, CA on Monday, May 11, 2015 - 08:21 am:

Noisy reverse is a common issue with Model Ts. It rarely represents a problem and is usually due to worn triple and reverse drum gears. There is little you can do to correct the problem short of replacing gears. If I couldn't live with the noise, I'd purchase new slow and reverse drums and triple gears. A lot of work and money.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Monday, May 11, 2015 - 08:26 am:

I suspect the R-PMM test will show current coming from the magneto and that there's a disconnect somewhere, most likely in the switch.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Larry Smith on Monday, May 11, 2015 - 11:58 am:

The stock 3:63 ratio is the way to go. I bought a '13 roadster awhile back, and just by driving it around, I suspected it had 3-1 gears. when I pulled it down, sure enough it did. BTW, getting that rear end apart was a challenge. A former owner had used all the correct parts, and had to double nut the studs on the drive shaft spool to get the studs out, because the pinion gear is so big! With a later design rear end, it wouldn't have been difficult.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Georgetown TX on Monday, May 11, 2015 - 12:10 pm:

Generally a freshly rebuilt T transmission is quite noisy, particularly if all the gears did not come from the same unit originally. A worn out transmission is normally very quiet.
If it works OK I would drive it for a few thousand miles. It will get quieter. Or you will get used to the noise.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kevin Weeds on Monday, May 11, 2015 - 04:07 pm:

Great feedback, I think I will advise him to leave reverse and see how it beds in over time.
Steve the switch could be the issue, doing the test Royce posted when motor is running on Key should tell us what we need.
Being a 13 they say it shouldn't have a battery so it shouldn't have a 2 position switch either I guess? maybe it wasn't wired up correctly.
He wont be changing the diff he will just live with it as it will be a seldom driver, not like mine I try to drive it everyday. I'm pleased mine is correct.
Thanks for your advice Guys


Top of pagePrevious messageNext messageBottom of page Link to this message  By Warren F Rollins on Monday, May 11, 2015 - 04:30 pm:

It does have a two position switch for cranking using dry cells. Don.t think your friend will go that route but a garden tractor battery will work just fine


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kevin Weeds on Monday, May 11, 2015 - 06:54 pm:

Warren it has a 6v battery already in the car but with no charging system and not running on mag I guess it will flatten quicker than just using it to buzz the coils for start up and then switching over.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Les Schubert on Monday, May 11, 2015 - 08:57 pm:

3-1 gears without a auxilary transmission is a great way to break a crankshaft. If you were at sea level and flatland you could get away with it maybe!!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Wayne Sheldon, Grass Valley, CA on Tuesday, May 12, 2015 - 01:29 am:

A good standard 6 volt automobile battery should be able to run the car almost all day with a good charge. There are a lot of model Ts doing that being toured with clubs.
While I prefer keeping cars closer to vintage correct (as a matter of proper preservation), switching to a 12 volt automobile battery could be a better choice. It works a little more efficiently and is believed to be easier on the coils. A simple overnight charge should be adequate after a day's driving.

I am still hoping you can find the magneto problem to be an easy fix.
Drive carefully, and enjoy, W2


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kevin Weeds on Tuesday, May 12, 2015 - 02:43 am:

Les - Sounds a bit scary really but our town is dead flat and there are flat touring options so he can avoid steep hills until he decides how much he'll use it etc.
Royce - Done that test today and the good news is the mag is working. I used a 12v motorbike taillight and it glowed well even from fast idle, it brightened as I revved up the motor but it didn't blow the bulb. The voltmeter I had connected on the same points didn't read anything? Not sure why, I bench tested it before I left.
So maybe its an issue with the switch?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Wayne Sheldon, Grass Valley, CA on Tuesday, May 12, 2015 - 02:55 am:

Hopefully that "easy fix" I was hoping for! Tracing the circuit with a "working" voltmeter is the easiest way I know to find the problem at this point. There are a dozen places where the voltage can disappear.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kevin Weeds on Tuesday, May 12, 2015 - 03:27 am:

Wont have the T running again until July when the owner returns so might have to have a plan by then.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Wayne Sheldon, Grass Valley, CA on Tuesday, May 12, 2015 - 04:32 am:

Do you get to sit back and admire it till then?
(Beautiful car!)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Tuesday, May 12, 2015 - 08:04 am:

A little more about battery/no battery. Before introduction of the starter in 1919 Model T's didn't come with a battery. Theoretically it wasn't needed. But Ford was realistic enough to include a battery position on the ignition switch because in the real world it's sometimes easier to start on battery. I'm currently experiencing that. When I've been driving my 1915 roadster and it's warm, it will usually start easily on MAG with the first or second pull of the crank. But I haven't yet figured out starting on MAG when it's cold, so I carry a battery. It may start after half a dozen pulls, or it may not. If it doesn't, I just switch to BAT and it fires right up.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Larry Smith on Tuesday, May 12, 2015 - 01:22 pm:

You should have a wood coilbox in the car, unless it is a real late one. The switch, regardless of make will indicate where mag & bat are.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kevin Weeds on Tuesday, May 12, 2015 - 05:17 pm:

Steve thanks for that info that explain a bit more. On my 27 the other day when it was warm I switched to mag then hit the starter button and it fired up, tried again when cold and it wouldn't fire so perhaps same issue as yours.
Larry on the 13 I can see the switch ok, its just when running and I switch to mag the motor turns off?


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