Speedometer Recalibration Gear 83-93
01-18-2006, 11:15 PM
#32
Join Date: Jan 2006
Posts: 6
RE: Speedometer Recalibration Gear 83-93
Hey, I did a search b/c my speedo is off by a good 15 mph. I went to http://www.tciauto.com/components/sp...gears.htm#ford
I have a 91 GT with 3.73 gears. This site suggests a 23 tooth white gear that is retrofitted for fords with 3.73 and 4.10 rear end gears.
Anyway, just my 2 cents.
I have a 91 GT with 3.73 gears. This site suggests a 23 tooth white gear that is retrofitted for fords with 3.73 and 4.10 rear end gears.
Anyway, just my 2 cents.
02-10-2006, 09:50 PM
#33
6th Gear Member
Join Date: Feb 2006
Location: Howard City, MI
Posts: 5,956
RE: Speedometer Recalibration Gear 83-93
I have a 87 with after market 3.73 gears. When I bought it the speedo was reading fast, so I got a GPS to see how fast I was going and roughly figured out how fast it was. I was told by a ford tech that each tooth is worth about 6 to 7mph(add one tooth, lose 6 to 7 mph on the speedo. Lose one tooth gain 6 to 7 mph on the speedo). I was fast by about 12mph and went from a 19 tooth to a 21 and it is just right. Now the only problem is I have more miles on the speedo from running it like that and you can fix that without doing major surgery. One question though, I want to switch from a 85mph to a 140mph speedo. How do I do that? What will it do to my speed reading? Will I have to regear it again?
05-19-2009, 12:06 AM
#34
Join Date: May 2009
Location: Illionois
Posts: 1
A little Info
The 2.3 liter mustangs (fox body) came with a 23 tooth to match up with the 3.73 gear in the 8.8 inch rear end. I have a 91 with a tremec and 5.0 and the 23 tooth is perfect, with a 3.73 rear end and 17" Pony R's.
The way the factory ran it is usually pretty close to accurate, even with a slight tire size change. Mine is not significant as the stock wheels were 16" and the new are 17" with a lower profile tire.
The way the factory ran it is usually pretty close to accurate, even with a slight tire size change. Mine is not significant as the stock wheels were 16" and the new are 17" with a lower profile tire.
05-19-2009, 12:22 AM
#35
6th Gear Member
Join Date: Jul 2006
Location: San Diego, CA
Posts: 6,882
The 2.3 liter mustangs (fox body) came with a 23 tooth to match up with the 3.73 gear in the 8.8 inch rear end. I have a 91 with a tremec and 5.0 and the 23 tooth is perfect, with a 3.73 rear end and 17" Pony R's.
The way the factory ran it is usually pretty close to accurate, even with a slight tire size change. Mine is not significant as the stock wheels were 16" and the new are 17" with a lower profile tire.
The way the factory ran it is usually pretty close to accurate, even with a slight tire size change. Mine is not significant as the stock wheels were 16" and the new are 17" with a lower profile tire.
04-06-2010, 03:44 PM
#38
Join Date: Jun 2005
Posts: 32
I have a 1991 5.0 with a T-5 trans (factory),3:73 gears, rear tire size of 255/40/17. From my knowledge it already has a 23 tooth speedo gear but the MPH is way off (reads much higher per Sneecer). I will have to pull the speedo gear out and confirm that it's indeed a 23 tooth unit.
Can anyone please comment on my tire size and which speedo gear I should go with?
Thanks,
Eric
Can anyone please comment on my tire size and which speedo gear I should go with?
Thanks,
Eric
07-15-2010, 02:15 PM
#40
Join Date: Jul 2010
Location: Texas
Posts: 29
Yes the gear will work the same way... I have taken a 140mph clust from a 89GT, then put it in an 89XL 4cyl turbo, and last weekend I put it in 88GTvert... but they all had stock rear ends, I am putting in a newly rebuilt 8.8 posi with 3.55 gears so i am ordering the black gear from steeda... great info