Rallye odometer gear issue

[70Dart340V8]

I just got around to breaking down my dash in my 1970 Dart Swinger 340. Apon testing some of the gauges I realized my speedometer didn't turn more than 1/4 to 1/2 an inch. Once I removed the speedometer and had a closer look at it I saw that the small 1" (or so) odometer gear was snapped causing the spinning portion of the speedometer to catch. I've been looking around online and can't seem to find this small plastic piece anywhere. I haven't seen any posts about it in any forms anywhere and haven't been able to find one on any website. Its a small plastic piece that runs off the input shaft and goes to the gears for the odometer and trip. Has anyone had this problem or know what exactly this part is and/or how I can aquire a new one? I'll post some pictures as soon as possible. Thanks

 

[4spdragtop]

Welcome aboard! I would think your best bet would be to buy another speedo/odo either to replace or to scab for the part you need.
If you google Mr Heaterbox, they redo tachs, speedos, heaters. Im sure if you give them a call they will have what you need or can repair yours. They are pricey tho, Dad n I had 2 tachs and Dad had his 150 speedo rebuilt.

 

[70Dart340V8]

Here's a photo of the gear and where it went. You can see the threads on the input shaft and where it connected to the other shaft. (On the left of photo)

 

[70Dart340V8]

I was considering that. If it turns out I can't get the part I will probably just install it back in the way it is and have it rebuilt down the road. I have some other things I'd like to get done on it before that. At least the speedo works

 

[Rocky_JS]

pretty common, replace the bracket assembly as the plastic gear is set into place on the bracket. All brackets are the same from 68 up w/120 or 150.

you need to remove the needle (gently twist and pull off) and remove at least two of the rivets holding the face on. You will now have access to the two screws that hold the bracket to the housing. remove bracket and stand up use a small punch into the speedo cable hole and tap lightly this will remove the brass collar. remove magnet assembly from the bracket and place into new bracket, this should help maintain speedo calibration. re-install in reverse.
The rivets are brass semi-tubular 3/32x1/8 long, aluminum ones will work also and are easier to install if you don't have a squeezer

 

[70Dart340V8]

Do you know where a good place to buy the bracket is?

 

[Rocky_JS]

pm sent

 

[RedFish]

I've been into about a dozen of these speedometers. Every one that had a failure in the odometer section had worn out and broken up in the trip clock digits. There are a whole bunch of tiny gears and cogs in between those digit wheels. I haven't seen this nylon gear broken before but I aint seen it all, don't know it all. Based on what I have seen and do know,
I'll venture to say a good gear alone wouldn't fix it because the root of the problem is in the digit spools.