but not new to message boards. Just bought a 1990 f-150 (see sig for details). It's in pretty good shape for a work truck. 116K on the clock and most everything works except for the air (seems to need freon) and the power lock switch on the drivers side.

i checked the rear end cover to see what gear it has but the numbers stamped on the tag didn't see to be any gear ratio's. anyone know how i can tell what gear it has? also, any 351/auto 4wd drive guys, what kind of mileage are you getting?

 

Inside the drivers side door jamb is the Vehicle Certification Label. On it will be codes for various items. Look at the bottom, and you'll see a code under the word AXLE. Post that code, and we'll let you know.



Take care,
-Chris

 

well chris, as it would go whomever had the truck before me had to replace the door (mother caved it in with her bumper) and there is NO sticker. guess i'll have to open the chunk up and count teef.

 

Well, what you could do is mark the tire in one spot and the driveshaft in one spot. Lift the truck up off the ground and rotate the tire one full turn till that mark reaches it original location. As you are doing this have a friend count the number of times that the mark goes by and then figure out what is left over. If the shaft turns approximately 3 1/4 turns then you would have the 3.31 rear gear. Likewise for 3 1/2 turns - 3.55, 3 3/4 turns - 3.73. This will give you an idea of when you stand with that and it is much cleaner than pulling the back cover off and counting teeth. AND if it goes 4 times around on the driveshaft than consider yourself luck as someone has changed out the rear gears to a set of 4.10's. Which are very good for quick launches but can be a killer on the gas mileage.

Have Fun & Keep on Truckin'
Dean

 

The VC Label should be on the door jamb, not the door. More specifically, right around where the pin is that the door latches onto, on the body.

If it's not there, write down what was on the tag on the rear, and I'll decipher it for you.

Take care,
-Chris

 

I have a 2000 F150 and my dad has an 89 F150. On both of ours the gear ratio are the first three numbers stamped on the tag. There is a fairly large space between the numbers for example his 89 reads 3 55 for the first three numbers on the tag, hence a 3.55 ratio.

Hope that helps,

Tim

 

Welcome

 

i'll have to get back under it, but i swear the first 3 number were 890. a rock climber it ain't!!

i'll do the drive shaft thing and while i am at it i'll get that number. thanks for the help.