spedometer calibration question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

69CSTDawg · 01-19-2011, 12:39 AM

ive seen in the summit catalogs the speedo recalibrator for 92 n newer trucks with electronic transmissions,is there anyway to correct the speedo on older trucks like speedo gears with fewer or more teeth or anything else? or an aftermarket speedometer?

Plunkett · 01-19-2011, 02:22 PM

You can correct your mechanical speedometer by changing out the drive or driven gear in your transfercase. I believe Bowtieoverdrive.com has a calculator to tell you which one you need to replace.

msgross · 01-19-2011, 10:07 PM

There is also a ratio adapter... they come in all ratios...

http://www.transmissioncenter.net/sp...atio%20adapter

69CSTDawg · 01-19-2011, 11:08 PM

thanks for the info,looked on bowtieoverdrives.com and they had the gears for 700r4s and 200r4s will those work for others like TH400s? and which do yall think works better? gears or adapters?

**Zoomad75** · 01-19-2011, 11:18 PM

If you can't find the right gear combo you can use a GPS in a pinch until you do.

Plunkett · 01-19-2011, 11:29 PM

I think tci's website also has one.

pseudopimp · 01-20-2011, 11:52 AM

is there a way to know what drive gear you have without taking your transmission out of service? i would like to just order the correct driven gear tooth for my application, but don't know the drive gear.

Plunkett · 01-20-2011, 12:47 PM

Quote:

Originally Posted by pseudopimp

is there a way to know what drive gear you have without taking your transmission out of service? i would like to just order the correct driven gear tooth for my application, but don't know the drive gear.

You can take the driven gear and housing assembly out and try to count the teeth on the drive gear or try and see what color it is and that might help you. For some crazy reason, my truck had a 10 drive gear, so I had to replce the drive gear to get my speedo right.

pseudopimp · 01-21-2011, 04:23 PM

i thought you had to remove the tail housing to do the whole swap. is this correct? or can i just take out the housing assembly....that sounds too easy.

Plunkett · 01-22-2011, 12:08 AM

Quote:

Originally Posted by pseudopimp

i thought you had to remove the tail housing to do the whole swap. is this correct? or can i just take out the housing assembly....that sounds too easy.

It depends on which gear you have to replace. I had to replace the drive gear on my tc, so I had to pull the tailshaft off my tcase. It was really easy to do tho.

01-19-2011, 12:39 AM	#1
69CSTDawg Registered User Join Date: Dec 2010 Location: Conyers,Ga Posts: 24	spedometer calibration question ive seen in the summit catalogs the speedo recalibrator for 92 n newer trucks with electronic transmissions,is there anyway to correct the speedo on older trucks like speedo gears with fewer or more teeth or anything else? or an aftermarket speedometer?

01-19-2011, 02:22 PM	#2
Plunkett Registered User Join Date: Nov 2009 Location: Chattanooga, TN Posts: 140	Re: spedometer calibration question You can correct your mechanical speedometer by changing out the drive or driven gear in your transfercase. I believe Bowtieoverdrive.com has a calculator to tell you which one you need to replace. __________________ 1987 gmc sierra v1500. 350 tbi, 700r4, 6" sky jacker lift, 15" Mickey Thompson wheels, and 35" bf Goodrich km2 tires.

01-19-2011, 10:07 PM	#3
msgross Registered User Join Date: Jul 2006 Location: Central PA Posts: 12,201	Re: spedometer calibration question There is also a ratio adapter... they come in all ratios... http://www.transmissioncenter.net/sp...atio%20adapter __________________ The Garage: 1968 K-10 SWB - "Project Money Pit" 1996 Z-71 - "huntin rig" 1969 C-10 LWB (SOLD) "Project flip that truck or else" 1993 Passport, F@rd 1-ton (SOLD)"Project Cousin Eddie" My Garage Build "The 1,000 footer"

01-19-2011, 11:08 PM	#4
69CSTDawg Registered User Join Date: Dec 2010 Location: Conyers,Ga Posts: 24	Re: spedometer calibration question thanks for the info,looked on bowtieoverdrives.com and they had the gears for 700r4s and 200r4s will those work for others like TH400s? and which do yall think works better? gears or adapters?

01-19-2011, 11:18 PM	#5
Zoomad75 K5Camper Join Date: Mar 2004 Location: Pueblo, CO Posts: 1,513	Re: spedometer calibration question If you can't find the right gear combo you can use a GPS in a pinch until you do. __________________ Rob Z. 1975 K5 350/465/205/D44/12b 4" lift on 35's- RIP 1991 K5 8.1L/NV4500/241/D44/14b FWC Camper Last edited by Zoomad75; 01-19-2011 at 11:18 PM.

01-19-2011, 11:29 PM	#6
Plunkett Registered User Join Date: Nov 2009 Location: Chattanooga, TN Posts: 140	Re: spedometer calibration question I think tci's website also has one. __________________ 1987 gmc sierra v1500. 350 tbi, 700r4, 6" sky jacker lift, 15" Mickey Thompson wheels, and 35" bf Goodrich km2 tires.

01-20-2011, 11:52 AM	#7
pseudopimp Registered User Join Date: May 2010 Location: Las Cruces NM Posts: 85	Re: spedometer calibration question is there a way to know what drive gear you have without taking your transmission out of service? i would like to just order the correct driven gear tooth for my application, but don't know the drive gear. __________________ 84 Scottsdale LWB K10 Rooting against the cowboys is almost as fun as rooting for the GIANTS!

01-21-2011, 04:23 PM	#9
pseudopimp Registered User Join Date: May 2010 Location: Las Cruces NM Posts: 85	Re: spedometer calibration question i thought you had to remove the tail housing to do the whole swap. is this correct? or can i just take out the housing assembly....that sounds too easy. __________________ 84 Scottsdale LWB K10 Rooting against the cowboys is almost as fun as rooting for the GIANTS!



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.