Speedo calibration with 4.10's.QUICK!

todd95GT · 10-11-2001, 09:16 AM

Ok, I have an appointment to have 4.10's installed next week. I just called the shop to find out if the price included the speedo gear to get the speedo where it should be. The tech said that with 4.10's and a speedo gear, the clock will still be about 7-9 miles per hour high. AND, there's no way to get it right w/o pulling the tranny and tailshaft to swap tranny gears, and even then it won't be accurate. Obviously, I don't want that. Even with 3.73's, he said the speedo will still be 2-4 mph off even with the speedo gear. Now what? You guys have this problem? Another shop told me no problem and now I don't know which way to go. Who's telling me the truth?

------------------
Todd
1995 GT/T-5
Pulleys; 65 mm TB; Flowmaster cat-back; Mac off road H-pipe; FMS aluminum driveshaft; short-throw shifter; HD clutch; Cobra R's; Cobra front and wing

jz_mustang50 · 10-11-2001, 10:41 AM

I'm intested in finding the same fix. My speedo with the 4.10 gears read (for instance) 140, when i was only going 100. So, it was way off... So far off I pulled the gear from the tranny so it now reads zero. Better that then having the wrong speed and getting a million miles on your odometer. I heard that you can get a "reducer" that fits in like with your speedometer cable, that changes how fast the speedometer cable spins. If anyone has more information about that let me know too!

------------------
Joe Zemaitis, Grand Rapids Michigan

1991 Mustang GT. Mods to date: 4.10 rear end, new POSI, aluminum driveshaft, AOD w/ shift kit, 2 1/2 off road h-pipe, 2 1/2 flowmasters and 2 1/2 tail pipes. Electric fan, Removed air pump and egr tube. Hotchkins upper and lower control arms. New energy suspension rear busings. Hoosier Quick Time Pro 27x10.5x15 and bolt on subframes soon to be welded. Everything else is STOCK. Totally stock ENGINE. 14.29@96 with 130k miles.

John · 10-11-2001, 06:24 PM

When my 4:10's were installed I was driving out to the track @ 70 mph, called the wife behind me on the cell and asked her what she was reading. 70 mph baby, she drives a 96 Jimmy. I have the pink (I believe) gear, the one for 3:73's.

------------------
89 Notch: ASP Pullies,
K&N Air,Transgo shiftkit,Trans. cooler,FMS 3 core , FMS 4:10's, 1.5" cowl, cold air kit, hooker shorties(jet hot coated), O/R H-Pipe, ASP solid mounts, Energy Sus. Trans. Mnt. BBK 70mm TB, MSD 6al, Dual elec. fans, 5.0 Firepower Kit, Scorpion 1.6 RR's, Flowmasters, 73 mm MAF, cobra intake(ported), 1" phenolic spacer,ported stock heads and crower #512 cam.

andy669 · 10-11-2001, 08:14 PM

Todd, Most likely your trans has a 8 tooth drive gear. (green) For the speedo to be correct you will need a 6 tooth drive gear (black) and a 20 tooth driven gear. (black) It shouldnt take an experienced mechanic more than a couple hours to change them.
andy

------------------
3 Black 94 GT Vert. AODE/TKO conversion, 3:73's, ported X-305's, GT40 manifolds, 75mm TB, 30lbers, PMS, 300 horse Top Gun wet kit, and all the other little stuff

Killercanary · 10-11-2001, 10:50 PM

Go to Hanlon's website, they have a graph on there to tell you what you need. I believe I have the 6 tooth with a 19 tooth- my speedo is DEAD on. I did have to yank the rear housin to install the 6 tooth gear though.

------------------
1995 NA GT CONVERTIBLE
BEST ET: 12.92
BEST MPH: 106.85
AFR's, FTI cam, edelbrock intake, EEC TUNER and lots more.
http://www.angelfire.com/pa2/killercanary

Killercanary · 10-12-2001, 09:42 AM

Todd, here's the address. http://www.hanlonmotorsports.com
Thanks for the email! You'll love dealing with Ed Curtis, he's a great guy that's very helpful.

------------------
1995 NA GT CONVERTIBLE
BEST ET: 12.92
BEST MPH: 106.85
AFR's, FTI cam, edelbrock intake, EEC TUNER and lots more. http://www.angelfire.com/pa2/killercanary

[This message has been edited by Killercanary (edited 10-12-2001).]

todd95GT · 10-12-2001, 11:40 AM

Thanks guys. The tech looked it up and came up with the same combo, a 6 and a 19. 4.10's going in next week!!!!!Going to ost a little more but it's worth it to have a correct speedo.

------------------
Todd
1995 GT/T-5
Pulleys; 65 mm TB; Flowmaster cat-back; Mac off road H-pipe; FMS aluminum driveshaft; short-throw shifter; HD clutch; Cobra R's; Cobra front and wing

10-11-2001, 09:16 AM	#1
todd95GT Registered Member Join Date: Aug 2001 Location: Palm Beach Gardens, Florida, USA Posts: 191	Speedo calibration with 4.10's.QUICK! Ok, I have an appointment to have 4.10's installed next week. I just called the shop to find out if the price included the speedo gear to get the speedo where it should be. The tech said that with 4.10's and a speedo gear, the clock will still be about 7-9 miles per hour high. AND, there's no way to get it right w/o pulling the tranny and tailshaft to swap tranny gears, and even then it won't be accurate. Obviously, I don't want that. Even with 3.73's, he said the speedo will still be 2-4 mph off even with the speedo gear. Now what? You guys have this problem? Another shop told me no problem and now I don't know which way to go. Who's telling me the truth? ------------------ Todd 1995 GT/T-5 Pulleys; 65 mm TB; Flowmaster cat-back; Mac off road H-pipe; FMS aluminum driveshaft; short-throw shifter; HD clutch; Cobra R's; Cobra front and wing

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10-11-2001, 10:41 AM	#2
jz_mustang50 Registered Member Join Date: Sep 2001 Location: Grand Rapids, Michigan, USA Posts: 50	I'm intested in finding the same fix. My speedo with the 4.10 gears read (for instance) 140, when i was only going 100. So, it was way off... So far off I pulled the gear from the tranny so it now reads zero. Better that then having the wrong speed and getting a million miles on your odometer. I heard that you can get a "reducer" that fits in like with your speedometer cable, that changes how fast the speedometer cable spins. If anyone has more information about that let me know too! ------------------ Joe Zemaitis, Grand Rapids Michigan 1991 Mustang GT. Mods to date: 4.10 rear end, new POSI, aluminum driveshaft, AOD w/ shift kit, 2 1/2 off road h-pipe, 2 1/2 flowmasters and 2 1/2 tail pipes. Electric fan, Removed air pump and egr tube. Hotchkins upper and lower control arms. New energy suspension rear busings. Hoosier Quick Time Pro 27x10.5x15 and bolt on subframes soon to be welded. Everything else is STOCK. Totally stock ENGINE. 14.29@96 with 130k miles.

10-11-2001, 06:24 PM	#3
John Registered Member Join Date: Dec 1998 Location: Ft.Myers, FL. Posts: 150	When my 4:10's were installed I was driving out to the track @ 70 mph, called the wife behind me on the cell and asked her what she was reading. 70 mph baby, she drives a 96 Jimmy. I have the pink (I believe) gear, the one for 3:73's. ------------------ 89 Notch: ASP Pullies, K&N Air,Transgo shiftkit,Trans. cooler,FMS 3 core , FMS 4:10's, 1.5" cowl, cold air kit, hooker shorties(jet hot coated), O/R H-Pipe, ASP solid mounts, Energy Sus. Trans. Mnt. BBK 70mm TB, MSD 6al, Dual elec. fans, 5.0 Firepower Kit, Scorpion 1.6 RR's, Flowmasters, 73 mm MAF, cobra intake(ported), 1" phenolic spacer,ported stock heads and crower #512 cam.

10-11-2001, 08:14 PM	#4
andy669 Registered Member Join Date: Jan 2001 Location: Moline Il Posts: 901	Todd, Most likely your trans has a 8 tooth drive gear. (green) For the speedo to be correct you will need a 6 tooth drive gear (black) and a 20 tooth driven gear. (black) It shouldnt take an experienced mechanic more than a couple hours to change them. andy ------------------ 3 Black 94 GT Vert. AODE/TKO conversion, 3:73's, ported X-305's, GT40 manifolds, 75mm TB, 30lbers, PMS, 300 horse Top Gun wet kit, and all the other little stuff

10-11-2001, 10:50 PM	#5
Killercanary Registered Member Join Date: Nov 1999 Location: Altoona, PA Posts: 336	Go to Hanlon's website, they have a graph on there to tell you what you need. I believe I have the 6 tooth with a 19 tooth- my speedo is DEAD on. I did have to yank the rear housin to install the 6 tooth gear though. ------------------ 1995 NA GT CONVERTIBLE BEST ET: 12.92 BEST MPH: 106.85 AFR's, FTI cam, edelbrock intake, EEC TUNER and lots more. http://www.angelfire.com/pa2/killercanary

10-12-2001, 09:42 AM	#6
Killercanary Registered Member Join Date: Nov 1999 Location: Altoona, PA Posts: 336	Todd, here's the address. http://www.hanlonmotorsports.com Thanks for the email! You'll love dealing with Ed Curtis, he's a great guy that's very helpful. ------------------ 1995 NA GT CONVERTIBLE BEST ET: 12.92 BEST MPH: 106.85 AFR's, FTI cam, edelbrock intake, EEC TUNER and lots more. http://www.angelfire.com/pa2/killercanary [This message has been edited by Killercanary (edited 10-12-2001).]

10-12-2001, 11:40 AM	#7
todd95GT Registered Member Join Date: Aug 2001 Location: Palm Beach Gardens, Florida, USA Posts: 191	Thanks guys. The tech looked it up and came up with the same combo, a 6 and a 19. 4.10's going in next week!!!!!Going to ost a little more but it's worth it to have a correct speedo. ------------------ Todd 1995 GT/T-5 Pulleys; 65 mm TB; Flowmaster cat-back; Mac off road H-pipe; FMS aluminum driveshaft; short-throw shifter; HD clutch; Cobra R's; Cobra front and wing