speedo gear
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From: Turlock CA
speedo gear
Ok I changed my pumkin from the 3.50 to 1 over to a 3.0 to 1. Speedometer looks to be about 5 mph off.
I am running a NP 435 granny tranny.
I pulled the speedo gear and it looks like it is a light red color maybe even pink. I counted the teeth and came up with 19 (counted three times) I was thinking I am gonna have to go to about a 17 teeth.
I called the local Kragen and the youngster there didn't know what I was talking about. It's a three day weekend so I will call Ford on Tuesday. Is there anywhere else I can buy a 17 teeth speedo gear. Ebay had 19 and higher.
Also I am thinking correctly here on going with less teeth right gentlemen?
It looks like I dropped the RPM's by 400 at 60 mph.
Thanks gentlemen.
jd
I am running a NP 435 granny tranny.
I pulled the speedo gear and it looks like it is a light red color maybe even pink. I counted the teeth and came up with 19 (counted three times) I was thinking I am gonna have to go to about a 17 teeth.
I called the local Kragen and the youngster there didn't know what I was talking about. It's a three day weekend so I will call Ford on Tuesday. Is there anywhere else I can buy a 17 teeth speedo gear. Ebay had 19 and higher.
Also I am thinking correctly here on going with less teeth right gentlemen?
It looks like I dropped the RPM's by 400 at 60 mph.
Thanks gentlemen.
jd
Last edited by jd_sylvia; Sep 4, 2005 at 08:11 PM. Reason: More info
Postmaster
Joined: Dec 1999
Posts: 2,813
Likes: 6
From: Connecticut
Hold the gear with the tip pointing upward and see which way the teeth are tilted towards... left or right. The overall length and the length of the tip are important. There are 3 common gear lengths. Less teeth makes it read faster, more makes it read slower. You're looking for a C3DZ 17271-B (7 teeth on the drive gear in tranny) or a DOTZ 17271-A ( 8 tooth drive gear ). More than likely it's the C3DZ-B gear, most common.
Barry
Barry
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Joined: Jul 2003
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From: Colville, Washington
The majority of the Mustang suppliers have the gears, I also saw somw in the Mac's catalog. Ford still has them available new. My parents '98 uses one with a C prefix part number!!
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Mountain Pass
Joined: Oct 2004
Posts: 205
Likes: 0
From: Southern California
Speedo gear
Just went throught this going from a Fordomatic with 3.7 to an AOD with 3.25 with new tires. The Ford-o-matic gear was compatible with the AOD.
Try this link & punch in your numbers. www.bgsoflex.com/speedo1.html
Transmissioncenter.net has lots of gears. Good luck.
Try this link & punch in your numbers. www.bgsoflex.com/speedo1.html
Transmissioncenter.net has lots of gears. Good luck.
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Postmaster
Joined: Dec 1999
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From: Connecticut
Many local Ford dealers have them on the shelf or can get them next day. That way you don't have to wait for the repo guys to ship them. I can order parts up until 4 pm and they are there at my dealership by 3 am the next morning. Can't beat that for delivery time. Even if it's in our national depot (Detroit), I have them in 2 days. I just ordered a floor for a 03 Escape and it was there in 2 days from Detroit! So, try the local dealer first before you order it.
Barry
Barry
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From: Turlock CA
So I called a speedometer palce in southern CA and they had me run a test. They told me to drive a known 10 mile distance and record the differance. WOW in a none ten mile distance the odometer only recorded 8 miles. It is a lot further off than I thought it would be.
They want $100.00 to add a special gearbox to the cable to correct it they claim that you can't get it with gears. I am planning a OD instal in the future so I passed on that idea.
I think that I am gonna take Barry's advice and go to Ford and get one with two less teeth and start there. For a hundred bucks I can buy a set of gears to make it closer than it is now. Gearvendor will fit up the right speedo for the OD.
Thanks Guys
jd
They want $100.00 to add a special gearbox to the cable to correct it they claim that you can't get it with gears. I am planning a OD instal in the future so I passed on that idea.
I think that I am gonna take Barry's advice and go to Ford and get one with two less teeth and start there. For a hundred bucks I can buy a set of gears to make it closer than it is now. Gearvendor will fit up the right speedo for the OD.
Thanks Guys
jd
Mountain Pass
Joined: Oct 2004
Posts: 205
Likes: 0
From: Southern California
Speedometer drive gears
JD -
I smell an attempted hornswaggle here. I'm sure you did too. The math seems simple enough - you need 20% more teeth. I still recommend you investigate the drive gear calculator I recommended previously.
I'm going through the same thing with my '59 ( I usually post on the 48-50 forum). I will have 17, 18, and two 19 toothed gears soon. I have a 17 in now and it's too slow. I'll gladly send you what I don't use. They're small and postage is cheap. Let's keep the spares in the family. I'm gone fishing 'til Tuesday so I won't know what works 'til late next week.
KW
I smell an attempted hornswaggle here. I'm sure you did too. The math seems simple enough - you need 20% more teeth. I still recommend you investigate the drive gear calculator I recommended previously.
I'm going through the same thing with my '59 ( I usually post on the 48-50 forum). I will have 17, 18, and two 19 toothed gears soon. I have a 17 in now and it's too slow. I'll gladly send you what I don't use. They're small and postage is cheap. Let's keep the spares in the family. I'm gone fishing 'til Tuesday so I won't know what works 'til late next week.
KW
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From: Turlock CA
KW
I think I will need to go with less teeth than I have correct? I currently have a 19 tooth so I was going to try a 17 tooth. I was hoping to try it this weekend so I may just buy one.
Thanks for the offer.
Also nice panel.. and hope you do well on the water..
I am also a fishing nut.
jd
I think I will need to go with less teeth than I have correct? I currently have a 19 tooth so I was going to try a 17 tooth. I was hoping to try it this weekend so I may just buy one.
Thanks for the offer.
Also nice panel.. and hope you do well on the water..
I am also a fishing nut.
jd
Last edited by jd_sylvia; Sep 7, 2005 at 10:17 PM.
Fleet Owner
Joined: Jun 1999
Posts: 24,552
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From: Creedmoor, North Carolina
JD, I have found that a tooth is generally good for .25 gear ratio. A trip to the junk yard makes a cool trip and picking up a part for $.50 will give you a good feeling too. IMHO
John
John