Hello! How can I change the gear ratio in my truck? It is also a 4wd so would I need to change the gearing up front as well? Thank you for the help.

 

If you have 3.73 with a LSD you should have a 9.75 rear axle, find your axle code and try to figure that out, if it turns out to be a 9.75, here is a front and rear kit

http://www.ebay.com/itm/Ford-9-75-8-...-/251463595836

 

If your asking how...you will need to find a good shop to do the work for you and yes... you have to do both front and rear to match.

 

As techrep states, its best to leave gear change swaps to a good shop that have the expertice and equipment to do it. The ring and pinion gears have to be shimmed correctly to obtain the correct mesh pattern, something I would not trust myself to do. IMO, this one is best left to an expert to perform.

 

How do you tell or determine what gear ratio is in the truck? Sorry for the stupid question.

 

Look at the door tag for the axle code and assume it is stock, google axle code or

Mark the drive shaft and turn it and count the wheel rotation. ! rotation of the drive shaft should turn the wheel 3.55, 3.73 or 4.11 turns. or

You could pull the rear diff cover drain the oil, count the gear teeth on the pinion and count the teeth on the carrier divide the two and you will have your answer

You choose the amount of work you want to do

 

You can also check the tag at the differential cover. Here are the codes for Ford F150 trucks as obtained from a Google search:

Axle Codes

non-limited slip

X27 – 3:31
X19 – 3:55
X26 – 3:73
X25 – 4:10

limited slip

H9 – 3:55
B6 – 3:73
B5 – 4:10


Check the rear axle bolt cover there will be a metal tag on the passengers side.
The numbers closest to the bolt holding the tag on will be your gear ratio. So if it shows 3L73, then you have 3.73 gears w/ limited slip.

 

I have checked my label and mine has the H9 code for a 3.55 ratio.

Thanks for the information. This was very helpful.