I need some advice!!
Thread Starter
|
Posting Guru
Joined: Jan 2004
Posts: 1,482
Likes: 0
From: Topeka, Ks.
I need some advice!!
I would like to get my speedo corrected in my 86 F150. I know it is way off and have FINALLY got the silly thing to run right. Now I am down to getting the speedo correct.
Here is what I have:
86 F150 with a 302.
Trans. type K
Axle type 18
Tires are P235/75/R15
I know on this type of tranny it is just a matter of changing the speedo gear but which one do I need?
Mark
Here is what I have:
86 F150 with a 302.
Trans. type K
Axle type 18
Tires are P235/75/R15
I know on this type of tranny it is just a matter of changing the speedo gear but which one do I need?
Mark
Postmaster
Joined: Aug 2003
Posts: 3,705
Likes: 4
From: Wichita KS
Hey Mark,
Here is a link to TCI transmision's gear calculator, enter the numbers and it will tell you what gear you need.
http://www.tciauto.com/tech_info/speedo_gears.htm
Duane
Southeast Kansas Coordinator
Here is a link to TCI transmision's gear calculator, enter the numbers and it will tell you what gear you need.
http://www.tciauto.com/tech_info/speedo_gears.htm
Duane
Southeast Kansas Coordinator
Post Fiend
Joined: Jan 2004
Posts: 6,610
Likes: 2
From: Northwest, Arkansas
According to the chart it should be a 3.00 check the following thread.
https://www.ford-trucks.com/forums/s...ht=axle+codes+
https://www.ford-trucks.com/forums/s...ht=axle+codes+
Trending Topics
Posting Guru
Joined: Jan 2004
Posts: 1,216
Likes: 0
Mark,
If you've changed Tires size this link will help you figure that:
http://www.miata.net/garage/tirecalc.html
If you've changed Tires size this link will help you figure that:
http://www.miata.net/garage/tirecalc.html
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Thread Starter
|
Posting Guru
Joined: Jan 2004
Posts: 1,482
Likes: 0
From: Topeka, Ks.
According to Jons link, I am 9% off on my speedo. 60 mph = 65.3 actual.
Thanks Jon!!
Duane, without putting too much thought into this, will a driven speedo gear that is 9% smaller give me the correct readings?
Mark
Thanks Jon!!
Duane, without putting too much thought into this, will a driven speedo gear that is 9% smaller give me the correct readings?
Mark
Postmaster
Joined: Aug 2003
Posts: 3,705
Likes: 4
From: Wichita KS
I thought code 18 was a 3.08 gear 3800# capacity open diff??
Mark, You should pull the drive gear out of the tranny and see what color it is. Then look at the door sticker and see what tire size originally came on the truck. Then call ford and tell them what the truck originally had for axles and tires then tell them what you have now. If they ask your tires revolution constant is around 9.72.
Just going with a drive gear that is 9% smaller won't work since the ratio for the gear is a combonation of both gears so using a 9% smaller gear will get you about 12% speedo difference.
Duane
Southeast Kansas Coordinator
Mark, You should pull the drive gear out of the tranny and see what color it is. Then look at the door sticker and see what tire size originally came on the truck. Then call ford and tell them what the truck originally had for axles and tires then tell them what you have now. If they ask your tires revolution constant is around 9.72.
Just going with a drive gear that is 9% smaller won't work since the ratio for the gear is a combonation of both gears so using a 9% smaller gear will get you about 12% speedo difference.
Duane
Southeast Kansas Coordinator
Postmaster
Joined: Aug 2003
Posts: 3,705
Likes: 4
From: Wichita KS
I just did all the math and pulled the drive gear out of my 85 just to check, then called ford and you need a 17 tooth gear to correct the speedo, and they run about 8 bucks.
Duane
Southeast Kansas Coordinator
Duane
Southeast Kansas Coordinator
Thread
Thread Starter
Forum
Replies
Last Post