speedometer is off

1BADSTANG · June 16th, 2008, 06:26 PM

my speedo is way off, i just had a gear change (3.73) and the shop put the red gear in like they should. The speedometer was off when i bought it, so this tells me maybe there is something more serious, what should i do?

shadowgames81 · June 16th, 2008, 06:35 PM

Are your rims a different size? That'll throw it off but they usually try to compensate w/ the tire size.

chickenbot · June 16th, 2008, 06:36 PM

is it the 88 gt with a 5 speed?

1slo5.0 · June 16th, 2008, 08:59 PM

What speedo gear is in it?

shadowgames81 · June 16th, 2008, 09:01 PM

said 3.73 rear gear and the red speedo gear.....is that the right combo?

1slo5.0 · June 16th, 2008, 09:12 PM

I guess I missed the red part.....

Assuming a 25.5-26 inch tire and the original 5 speed transmission the red gear is the correct gear for 3.73 gears.

How far off is the speedo and does it read faster than you are going or slower? Has the transmission ever been changed or rebuilt? Has the speedometer been changed? The factory 88 speedometer is an 85mph unit. If someone put a 140mph gauge face on the stock 85mph speedo it will read faster than what you are going. If the trans is a T5 from a 90-95 Mustang it will have an 8 tooth drive gear which will make your speedo read faster as well but is an easy fix by swapping the red 21 tooth gear for the white 23 tooth gear.

e3sean · June 16th, 2008, 09:15 PM

what color is the gear inside the tailshaft housing that the red speedo gear one rides on? there are 2 differnt ones there is a yellow one and a green one. yourse should be yellow.

1BADSTANG · June 16th, 2008, 09:46 PM

i have a ford racing 160mph unit. I bought it with thec ar, it as never right. It reads slower than i am going, i think at 28mph i am really doing like 39-40. I dont think the tranny was ever rebuilt. its shot now so i guess i killed the original one.

1slo5.0 · June 17th, 2008, 06:45 AM

Originally Posted by 1BADSTANG

i have a ford racing 160mph unit. I bought it with thec ar, it as never right. It reads slower than i am going, i think at 28mph i am really doing like 39-40. I dont think the tranny was ever rebuilt. its shot now so i guess i killed the original one.

Is it a Ford Racing speedo or a speedo out of a cop car? I'm betting the speedo is your problem.

e3sean · June 17th, 2008, 11:26 AM

put the stock speedo gear back in i bet it will help get it closer it should bring your reading up about 15 mph.

June 16th, 2008, 06:26 PM	#1
1BADSTANG Hardcore Enthusiast Join Date: Sep 2007 Location: long island Posts: 1,515 iTrader: 0 reviews	speedometer is off my speedo is way off, i just had a gear change (3.73) and the shop put the red gear in like they should. The speedometer was off when i bought it, so this tells me maybe there is something more serious, what should i do?

June 16th, 2008, 06:36 PM	#3
chickenbot Enthusiast 1990 mustang gt eventually Join Date: Nov 2007 Location: plano, tx Posts: 938 iTrader: 0 reviews	is it the 88 gt with a 5 speed? __________________ 1990 gt 5.0 Mac Performance 76mm straight shot intake 70mm Accufab tb and egr spacer Trick Flow Track Heat u/l intake 3.55 gears MSD distributor, Blaster Coil, and 8.5mm wires

June 16th, 2008, 08:59 PM	#4
1slo5.0 MM Ninjas! 1990 Mustang LX 9.36@143 mph Join Date: Jan 2006 Location: North Fond du Lac, Wisconsin Posts: 11,375 iTrader: 1 reviews	What speedo gear is in it? __________________ My daily driver has 16 cylinders and 4400hp @ 1000 rpm.... ***1988 Mustang GT - Stock....almost

June 16th, 2008, 09:12 PM	#6
1slo5.0 MM Ninjas! 1990 Mustang LX 9.36@143 mph Join Date: Jan 2006 Location: North Fond du Lac, Wisconsin Posts: 11,375 iTrader: 1 reviews	I guess I missed the red part..... Assuming a 25.5-26 inch tire and the original 5 speed transmission the red gear is the correct gear for 3.73 gears. How far off is the speedo and does it read faster than you are going or slower? Has the transmission ever been changed or rebuilt? Has the speedometer been changed? The factory 88 speedometer is an 85mph unit. If someone put a 140mph gauge face on the stock 85mph speedo it will read faster than what you are going. If the trans is a T5 from a 90-95 Mustang it will have an 8 tooth drive gear which will make your speedo read faster as well but is an easy fix by swapping the red 21 tooth gear for the white 23 tooth gear. __________________ My daily driver has 16 cylinders and 4400hp @ 1000 rpm.... ***1988 Mustang GT - Stock....almost

June 16th, 2008, 09:15 PM	#7
e3sean I Post Entirely Way Too Much 1988 lx 9.68@142 Join Date: Nov 2007 Location: goldsboro NC Posts: 5,609 iTrader: 0 reviews	what color is the gear inside the tailshaft housing that the red speedo gear one rides on? there are 2 differnt ones there is a yellow one and a green one. yourse should be yellow. __________________

June 16th, 2008, 06:35 PM	#2
shadowgames81 Hardcore Enthusiast 87 Coupe Join Date: Sep 2006 Location: Hampton, VA Posts: 1,220 iTrader: 3 reviews	Are your rims a different size? That'll throw it off but they usually try to compensate w/ the tire size.

June 16th, 2008, 09:01 PM	#5
shadowgames81 Hardcore Enthusiast 87 Coupe Join Date: Sep 2006 Location: Hampton, VA Posts: 1,220 iTrader: 3 reviews	said 3.73 rear gear and the red speedo gear.....is that the right combo?

June 16th, 2008, 09:46 PM	#8
1BADSTANG Hardcore Enthusiast Join Date: Sep 2007 Location: long island Posts: 1,515 iTrader: 0 reviews	i have a ford racing 160mph unit. I bought it with thec ar, it as never right. It reads slower than i am going, i think at 28mph i am really doing like 39-40. I dont think the tranny was ever rebuilt. its shot now so i guess i killed the original one.

June 17th, 2008, 11:26 AM	#10
e3sean I Post Entirely Way Too Much 1988 lx 9.68@142 Join Date: Nov 2007 Location: goldsboro NC Posts: 5,609 iTrader: 0 reviews	put the stock speedo gear back in i bet it will help get it closer it should bring your reading up about 15 mph. __________________

Remove Advertisements Sponsored Links
Ford Mustang Forum Advertisement

Threads Similar to: speedometer is off
Thread	Thread Starter	Forum	Replies	Last Post
Speedometer	djh1286	V6 Mustangs	12	January 5th, 2008 02:09 AM
Speedometer	akatagyourit	2.3 Mustangs	2	September 15th, 2007 01:24 AM
Speedometer	cdesha	96-98	6	August 15th, 2007 01:11 AM
Speedometer	Arhilion	96-98	8	May 23rd, 2007 07:36 AM
Speedometer	88MustangGT	5.0 Mustangs	8	January 3rd, 2007 07:11 AM

All times are GMT -4. The time now is 05:53 AM.
Contact Us - Modded Mustangs : Ford Mustang Forums - Privacy Statement - Top
Modded Mustangs is ©2005-2008, All Rights Reserved, And is Not Affiliated with Ford Motor Company. Forum is powered by vBulletin ©2000 - 2012, Jelsoft Ent. Ltd. & SEO by vBSEO 3.3.2 ©2009, Crawlability, Inc.