Correct Speedo Gear???

[69chargerdad]

We recently changed the tires to 295/50/15's with an outside diameter of 26", and the rear gear to a 3.55. Does anyone know what color gear we should be using or have a chart to figure it out?

thanks Ken and Marcus

[hemigeno]

The F70 x 15 tires on my R/T are just barely over 26" in diameter, so they are perhaps as close as you can get.  Might depend on where you are measuring from.  If you want to measure the circumference of your tires and compare that, mine are 85-3/4" measured at the center of the tread.

That application calls for the 35 tooth Orange speedometer gear.  P/N 2538935 if you're keeping score...



Geno

[694spdRT]

Does anyone have the gear listing page from the old Mopar books they can post? I have a 2005 catalog but, I didn't find it listed anymore....or am I just blind.

[hemigeno]

Are you talking about in the MP catalog?  I have an old one, and I didn't see it in there.  If you need something from the service and/or parts manual, I'll scan it in tomorrow if someone else doesn't post it before then.

I'm late for my 7 year old's baseball game, so I gotta run - sorry Ty!

Geno

[69chargerdad]

thanks hemigeno, il check the circumference and post back

[694spdRT]

Are you talking about in the MP catalog?  I have an old one, and I didn't see it in there.  If you need something from the service and/or parts manual, I'll scan it in tomorrow if someone else doesn't post it before then.

I'm late for my 7 year old's baseball game, so I gotta run - sorry Ty!

Geno

Hi Gene,

To be honest I borrowed an old MP catalog from my local dealer a few years ago and I think it was in there. I could be wrong though as I have looked through so much literature it all blends together. I remember it being a quick reference page that listed the different part numbers for various gear and tire combos. At the time I thought "boy this would be handy some day" and then turned the page. 

There is no rush in finding it as it is for the Challenger project and there are only about 2 years worth of other resto items to do before I actually need it. 

Thanks Ty

[firefighter3931]

Here's a chart showing the corresponding speedo gear based on axle ratio and tire diameter. The last 2 numbers of the part number represent the number of teeth on that specific gear. Some of these pn's have been superceded by new part numbers but this will tell you how many teeth you need to dial in your speedo. Just tell the dealer what gear you need and they can fix you up.

A 295/50/15 is 26.5in tall so the closest speedo gear would be a 36 or 35 tooth. I'd probably go with the 35 tooth if it were mine.  HemiGeno called it 

Ron



AXLE RATIO      24"       26"       28"           30"
2.76            2538930 2538928 2538926 2538924
2.94            2538932 2538930 2538928 2538926
3.21            2538935 2538933 2838931 2838929
3.55            2538939 2538936 2538933 2538931
3.91            2538943 2538940 2538937 2538935
4.10            2538945 2538942 2538939 2538936
4.30            2538944 2538941 2538938
4.56            2538945 2538943 2538940

[694spdRT]

Thanks Ron,

I am printing your chart off right now.

Ty

[69chargerdad]

           Me too.    Thanks Firefighter,              Ken