Speedo problem on A-904

cadboy · Post by **cadboy** » Sun Mar 16, 14 10:19 pm

I have had speedo not working since I got the car and the cable was new when bought the car, checked the cable end and not turning.

So today I took the speedometer pinion out, all looks nice and clean, no ware.

It has the orange colour gear.

I don't know if it is the correct one or not.

I have 3.91 gears in axle, wheel are 14"

Also have these stamped on the speedo pinion adaptor: 26.31; 32.33; 39.45.
Anyone know which is the correct one at 6 o'clock?

Any advice appreciated, thanks.

Cannonball · Post by **Cannonball** » Sun Mar 16, 14 10:25 pm

you will see a raised pip on the trans case line that up with the corresponding no on the housing that the no of teeth on the gear fal in to.

cadboy · Post by **cadboy** » Mon Mar 17, 14 6:44 am

Yes Dunc have noticed the raised pip on tranny housing, but which number should be lined up with the pip, and is the orange gear the correct one.

cheer.

Cannonball · Post by **Cannonball** » Mon Mar 17, 14 8:59 am

cadboy wrote:Yes Dunc have noticed the raised pip on tranny housing, but which number should be lined up with the pip, and is the orange gear the correct one.

cheer.

there is a no etched in to your gear, i dont know if its correct that all depends on diff ratio and tyre height etc,
fit it in the correct segment then go through a speed camera that will tell you

Dave-R · Post by **Dave-R** » Mon Mar 17, 14 10:00 am

Use this calculator I made to determin the correct tooth gear needed.
Just enter your tyre size and gear ratio.

http://challenger.mpoli.fi/web/AUTOMATICchart.xls

Dave-R · Post by **Dave-R** » Mon Mar 17, 14 10:03 am

Like Dunc says, the speedo pinion needs to be rotated so that the gear engages into the output drive shaft. The different coloured gears are different diameters so the adjustment makes up for that.

cadboy · Post by **cadboy** » Tue Mar 18, 14 7:07 am

All sorted and the speedo is now working

Thank you guys for your help and advice measured the tire and worked out to be 40 teeth gear and the orange gear is 40 teeth as stamped.

Put it all back in on 39.45 lined up to the pip, speedo is working.

Just have to check the speed (as Dunc said) with a speed camera

Cannonball · Post by **Cannonball** » Tue Mar 18, 14 8:35 am

cadboy wrote:All sorted and the speedo is now working

Thank you guys for your help and advice measured the tire and worked out to be 40 teeth gear and the orange gear is 40 teeth as stamped.

Put it all back in on 39.45 lined up to the pip, speedo is working.

Just have to check the speed (as Dunc said) with a speed camera

well done matey,,

just stick this plate on it for the camera test
M11 CDM

mopar_mark · Post by **mopar_mark** » Tue Mar 18, 14 4:10 pm

Cannonball wrote:go through a speed camera that will tell you

Cannonball wrote: just stick this plate on it for the camera test
M11 CDM