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3.23 and 727 speedo gear

Posted By: roy2345

3.23 and 727 speedo gear - 12/26/09 06:30 PM

I replaced my 2.76 gear with a 3.23 gear and now I need the correct speedo gear to go in the tranny. Right now it's 20 mph off. I don't totally understand the formulas etc. Just would like to know what would be standard gear from factory setup for a 70 Road Runner Auto with 3.23 gear and 727 tranny. Thanks!
Posted By: RUNCHARGER

Re: 3.23 and 727 speedo gear - 12/26/09 06:40 PM

32 will get you close depending on your tire size.

Sheldon
Posted By: 1_WILD_RT

Re: 3.23 and 727 speedo gear - 12/26/09 06:45 PM

Rather than a formula how about a chart...

http://www.yearone.com/yodnn/tech/TechFA...15/Default.aspx
Posted By: roy2345

Re: 3.23 and 727 speedo gear - 12/26/09 06:45 PM

ok..where do I get it at the BEST price?
Posted By: 1_WILD_RT

Re: 3.23 and 727 speedo gear - 12/26/09 06:53 PM

http://cgi.ebay.com/ebaymotors/DODGE-MOP...=item414ba7e5c1
Posted By: stumpy

Re: 3.23 and 727 speedo gear - 12/26/09 08:14 PM

Did you get the noise figured out? That's the first thing I'd worry about.
Posted By: roy2345

Re: 3.23 and 727 speedo gear - 12/26/09 08:43 PM

yeah, dude tore it back down and adjusted something inside. Works like a champ. I just would like the speedo more accurate
Posted By: roy2345

Re: 3.23 and 727 speedo gear - 12/26/09 08:51 PM

Will 33 read too slow? If so I believe I'll order the 32....I have 17"x 8" wheels with 235 60 17 tires
Posted By: 1_WILD_RT

Re: 3.23 and 727 speedo gear - 12/26/09 08:59 PM

Tire should be 28.3 tall use a 30 tooth gear...

BTW are you aware of how to "clock the gear adapter"...

Posted By: roy2345

Re: 3.23 and 727 speedo gear - 12/26/09 09:06 PM

no clue about clocking an adapter..I just can't screw it in?
Posted By: 1_WILD_RT

Re: 3.23 and 727 speedo gear - 12/26/09 09:11 PM

If you look at the picture I posted you'll see segments are marked for gear tooth numbers... select the proper segment & align it with the 6 o'clock position & bolt the adapter in...
Posted By: IMGTX

Re: 3.23 and 727 speedo gear - 12/26/09 09:13 PM

Clocking is easy.

It isn't very clear in that pic but under the arrow at the 6'oclock position there is a dot cast into the extension housing. That dot roughly lines up with the numbers that represent your gear.

i.e. if you have a #30 gear line the numbers 26-31 on the adapter to the dot.

Install the clamp with the tabs in the slots and your done.
Posted By: roy2345

Re: 3.23 and 727 speedo gear - 12/26/09 09:17 PM

MOP...=item414ba7e5c1 is what i ordered. Is this clocking device already on the tranny?
Posted By: 1_WILD_RT

Re: 3.23 and 727 speedo gear - 12/26/09 09:18 PM

Quote:

Clocking is easy.

It isn't very clear in that pic but under the arrow at the 6'oclock position there is a dot cast into the extension housing. That dot roughly lines up with the numbers that represent your gear.

i.e. if you have a #30 gear line the numbers 26-31 on the adapter to the dot.

Install the clamp with the tabs in the slots and your done.




I agree it is easy... But not knowing about it would be bad...
Posted By: 1_WILD_RT

Re: 3.23 and 727 speedo gear - 12/26/09 09:20 PM

Quote:

MOP...=item414ba7e5c1 is what i ordered. Is this clocking device already on the tranny?




care to clarify...
Posted By: roy2345

Re: 3.23 and 727 speedo gear - 12/26/09 09:23 PM

i thought all i needed to do was put a different numbered gear in the tranny into that housing. will my tranny have that adjustable dial on it?
Posted By: 1_WILD_RT

Re: 3.23 and 727 speedo gear - 12/26/09 09:25 PM

The adapter is adjustable, the hole where the gear passes through is offset... Look at the picture above...
Posted By: NachoRT74

Re: 3.23 and 727 speedo gear - 12/26/09 09:34 PM

Quote:

i thought all i needed to do was put a different numbered gear in the tranny into that housing. will my tranny have that adjustable dial on it?





a 28 teeth gear won't be ever same size/diameter piece than a for example 35 teeth

being diff diameter gears due diff teeth quantity will make some gears meet with the shaft and some gears not so thats the reason why the offset shape housing to get it closer to the shaft depending on the diameter of gear by the teeth account.

and yes you have that same piece on your tranny because is the part where you fit the speedo wire at tranny and infact where you mount the gear. It does also have casted the numbers rate where must be located into tranny according with the teeth account of gear. Tranny normally does have a DOT casted to set the clocking pointing out to that dot what as stated is at 6'oclock.

235/60 17 is 28.1" tall tire.

what I don't get is the calculator gives me a 30 teeth gear, and some charts gives 31

another usefull chart:

Attached picture 5690904-MoparSpeedoGearChart.jpg
Posted By: roy2345

Re: 3.23 and 727 speedo gear - 12/26/09 11:05 PM

so do i need a 32 or 31 gear?
Posted By: RapidRobert

Re: 3.23 and 727 speedo gear - 12/27/09 12:01 AM

I'd put a piece of flat stock on top of one of your rear tires and measure from the underside of it to ground for your exact diameter. With that # and your gear ratio (3.23) the simple chart in the archives worked for me dead on. Made my odo correct measured by the interstate mile markers and also my speedo correct measured at a roadside digital mph sign.
Posted By: 1_WILD_RT

Re: 3.23 and 727 speedo gear - 12/27/09 12:17 AM

Like I said earlier a 235/60-17 tire should be 28.3 tall and per the chart you would use a 30 tooth gear...
Posted By: roy2345

Re: 3.23 and 727 speedo gear - 12/27/09 01:21 AM

sorry guys.....the tire size is 225 55 17....so what gear would that be?
Posted By: stumpy

Re: 3.23 and 727 speedo gear - 12/27/09 02:13 AM

Measure the tire as instructed then look at the chart posted above. It's not rocket science. You just have to do a little work for yourself.
Posted By: IMGTX

Re: 3.23 and 727 speedo gear - 12/27/09 03:10 AM

Quote:

Quote:

Clocking is easy.

It isn't very clear in that pic but under the arrow at the 6'oclock position there is a dot cast into the extension housing. That dot roughly lines up with the numbers that represent your gear.

i.e. if you have a #30 gear line the numbers 26-31 on the adapter to the dot.

Install the clamp with the tabs in the slots and your done.




I agree it is easy... But not knowing about it would be bad...




Your right. I though I was helping but you are a much faster typer....
Posted By: 1_WILD_RT

Re: 3.23 and 727 speedo gear - 12/27/09 03:14 AM

Quote:

sorry guys.....the tire size is 225 55 17....so what gear would that be?




26.8 = 32 teeth
Posted By: roy2345

Re: 3.23 and 727 speedo gear - 12/27/09 03:52 AM

what I came up with 2...Thanks
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