adjust speedo?
Thread Starter
|
Junior User
Joined: Apr 2006
Posts: 90
Likes: 0
adjust speedo?
i have a 1975 f250 camper special with a 460/c6 trans, and when i bought it the guy told me that because the rear tires are so bigger than the stock tires that when im going 40mph im really going 30, and when i go 60 im really going 50...and so on. is there a way to change that so my mph is my acutual mph?
New User
Joined: Jan 2008
Posts: 0
Likes: 24
Post Fiend
Joined: Mar 2005
Posts: 8,542
Likes: 5
From: Louisiana
You need to change the speedometer gear, and the best way to do that, would be to go to broncograveyard.com
They have a calculation that can tell you which gear you need, and they sell all different kinds for a few bucks.
Or you could always change the gears in your axle, and then the truck would have better accleration, get better gas mileage, and correct the speedo.
They have a calculation that can tell you which gear you need, and they sell all different kinds for a few bucks.
Or you could always change the gears in your axle, and then the truck would have better accleration, get better gas mileage, and correct the speedo.
New User
Joined: Jan 2008
Posts: 0
Likes: 24
Originally Posted by MBBFord
You need to change the speedometer gear, and the best way to do that, would be to go to broncograveyard.com
They have a calculation that can tell you which gear you need, and they sell all different kinds for a few bucks.
Or you could always change the gears in your axle, and then the truck would have better accleration, get better gas mileage, and correct the speedo.
They have a calculation that can tell you which gear you need, and they sell all different kinds for a few bucks.
Or you could always change the gears in your axle, and then the truck would have better accleration, get better gas mileage, and correct the speedo.
I posted the the exact same thing you mentioned one post above yours.
A speedo gear calculator
Post Fiend
Joined: Mar 2005
Posts: 8,542
Likes: 5
From: Louisiana
Sorry Mil1ion, I fiqured you posted a link to a calculator, but I was just saying the one I knew too.
Trending Topics
Thread Starter
|
Junior User
Joined: Apr 2006
Posts: 90
Likes: 0
im not sure exactly its a pretty new truck for me, when i get home i'll measure. do i measure the outside diameter of my rim, or bottom of tire to top? also when i bought the truck the guy said it was pieced from 5 different trucks. whats the like ability of the gears ratio on my door to be the same in the axle?
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
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
Top 10 Ford Truck Tragedies
Joe Kucinski
Post Fiend
Joined: Mar 2005
Posts: 8,542
Likes: 5
From: Louisiana
Are the tires sizes metric? 285/75R15 or somthing like that, b/c if it is that size in the rear then they are 32" tall and 11" wide.
If the tire size is only about 32"tall, then your cheapest and best suited fix would be a new speedo gear.
BUT if you have the money, switching gears to about 3.73 would help acceleration and mileage a little bit.
If the tire size is only about 32"tall, then your cheapest and best suited fix would be a new speedo gear.
BUT if you have the money, switching gears to about 3.73 would help acceleration and mileage a little bit.
Post Fiend
Joined: Mar 2005
Posts: 8,542
Likes: 5
From: Louisiana
There is a number or letter on the driverside door jam that Mil1ion can help you out with if you need, or they have a metal tag on the rear bolt circle with numbers and letters on it, and if you get back to us on here with either of those we can let you know what gears came stock in the truck.
Posting Legend
Joined: Sep 2001
Posts: 30,255
Likes: 37
Gear a 460 as low numerically as you can for mileage. Some of the 460's with a 9" in cars that were heavier than these trucks were around 2.5:1 for mileage. You do NOT want to turn more RPM's with a 460 or they will suck gas bad!
Thread Starter
|
Junior User
Joined: Apr 2006
Posts: 90
Likes: 0
the guy that I bought my truck from said when he put in the 460 and c-6 trans, that it was geared really low and I could pull a stump out of the ground, and the other day I was driving and wasn't paying attention and I was driving 60 mph in 2nd gear? Is that GOOD or BAD?