How many teeth should a 2.76 speedometer gear from a 73 Dart have?
I got the speedo gear from the car that donated its 2.76 rearend.
I lifted one wheel and counted 11 U-joint caps for 2 wheel rotations.

The black gear has 29 teeth and (2) (9) is molded in.
Is that the right one?

I have my doubts and would like to confirm before I drain my transmission fluid.

What is your rear tire size?
FYI, if you jack the car up from the left rear, not much ATF will come out.
DD

195 70 R14 on 5" rims.
I think the diameter is 24.7 inches

the gear for 2.76's should be dark green and have 56 teeth. I took two of them out and both were dark green w/ 56 teeth (I'll give you one if you need it). Moparts has a chart that tells what gear to use with what ratio and tire size you are running.

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When parking my car backwards on an inclined driveway and jacking it up from the center of the rear axle, 0 atf came out when changing speedo cable gears. If you get it high enough on a flat driveway you should be ok too.

Don't bother draining... get a clean pan under there when you take it out and if anything does come out you can just put it back in.

Remember to get the alignment of the unit right when changing gears - theres a slot on the transmission, and the part that holds the gear has 4 slots on it with teeth ranges marked. If its not set right it will chew up the speedo gear.

Is that for an A-904 auto?
That's what I have.

Errr.... it will not be 56 tooth gear. 29 tooth is about right.
The most teeth you can get on a 66 & up Mopar speedo gear is 45 and that is used for the 4.30 / 4.56 rear end ratios

See this chart for the gear you should use.
DD

Doc, I didn't count the teeth but the gears have "56" stamped on the back of both of them.
Yes these came both out of 904 transmissions.

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The pinion I pulled from the pushbutton 1963 trans is not interchangeable with the pinion from the 73 Dart??!

What do I do now?
Where can I get a -29 gear for it?
The 63 part is in foreground.



I'll be here fishing out the gear fragment as I wait for your help.

BTW, is there somewhere I can see a picture of an unbroken gear, so I know what I'm fishing for?

I just ordered a 52068151 (which is what he said 2538929 crossed over to) from a local mopar dealer.
Does this sound like the correct part number?

I estimate the yellow gear had about 18 teeth.
That does not jive with Mopar Pinion Charts I've seen.
It should have had 30 teeth...

http://www.moparts.com/Tech/tech/pages/speedo.html

The gear piece went towards the pan.
If I remove the transmission pan, will I be able to retrieve the gear?

I have a 65 service manual, and it has pinion teeth from 16 to 21 teeth......

Orange is 17 teeth, which may be your faded yellow............

16 brown
17 orange
18 dark purple
19 dark blue
20 green
21 gray

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

I see SPEEDOMETER PINION USAGE CHART

If orange is 17 teeth, I guess I need a brown 16 tooth one to switch from a 2.93 to a 2.76.

Anyone know what the full part number was for the 16 tooth brown gear?

2.76 / 2.93 * 17 = 16.013


Sounds good to me. (that's if your speedo was accurate to begin with)

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

You might be able to determine if it had 18 or 17 teeth if there are remaining teeth opposite each other. Exactly opposite would be even, not quite odd amount of teeth. (and if you really want to make sure, figure out teeth spacing, and work your way around........)

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes