ok im trying to figure out what the trans od ratio is and transfer ratio is on a 03 ford f150 4x4 with 4.6l automatic and what would the most likely alxe ratio is im going to be changing to larger tires and would like to change the alxe ratio to get the same rpms at 55 mph that would with stock tires

 

Take a look at the door sticker on your truck. Get the numbers or codes where the sticker says AXLE and TR. Either list them here or use this link to find out yourself.

https://www.ford-trucks.com/article/...r_Decoder.html

Other FTE users will chime in to tell you what gear ratios to use with your chosen tire size. BTW, you will have to get gear sets for both axles, which will double the cost of a gear change. Good luck!

 

ok i will do

 

ok well i have a 3.55 axle and a 4r70w trans so does anyone know what the ratio out of trans and transfer case is in OD

 

might be interested to know the trans ratio, but you dont need that. if you change the tire diameter by 5%, then change the gears by 5%. if you change the tires by 10%, then change the gears 10%, etc.

 

http://www.vibratesoftware.com/html_...Main.htm#4R70W

 

https://www.ford-trucks.com/specs/2003/2003_f150_1.html

 

3.55 x .7 = 2.845 to 1 final, in OD.

 

thank you for all your help and websites for this i think ive got it figured out