I wouldn't mind changing the rear diff in my truck from 3.03s to 3.73s.

How much does it usually cost for it to be done (parts and labor)? Should I have ford make the change?

 

I spent a little over $500 having the gears replaced in my old T/A. I believe the gears were around $200, and the labor was around $300 if memory serves me correctly, however I was just having the rod and pinion replaced, I wasn't adding a locker or anything. Are you sure you have 3.03 gears in your truck? You didn't mention what year you've got, but I didn't know they even put 3.03 gears in new F-150's. From what I've read on here, going from 3.55 to 3.73 is almost unoticeable, but if you really at 3.03 you should tell some difference!

 

i must be crazy, but i can definatly tell a huge difference bewteen 3.55 and 3.73

 

It is a 2000 F-150 XLT. Yes, it has 3.03s. I have my window sticker and it is listed as having 3.03s.

Is there any other way I can check that doesn't involved jacking the truck up and spinning the tires around?

 

Intel,

Look at the Vehicle Certification Label on the driver side door piller. Under axle code you will see an 18 which is for the 3.08:1 axle. Check your sticker again and I am sure you will see a 3.08 not a 3.03 axle.

Regards

Jean Marc Chartier

 

yhea, my mistake, It is a 3.08 rear diff...

IT does say 18 on the inside of the door so I guess I've got them.

What all do I need to order parts wise?

 

You will need the Ring gear and pinion and the install kit, Diffewrential oil.

Check out the gear vendors like Richmond gear. http://www.richmondgear.com/ or
Randy's http://www.ring-pinion.com/home.html

These places have all the parts you will need. If you have never done one before have it done by a local shop and watch them do it.

Regards

Jean Marc Chartier

 

Anyone with experience and proper tools can do it; including Ford. Average labor price would be $300. Gears and parts can vary based on what the installation kit includes. Good mechanics will evaluate bearing condition; this is what the kits stage up to include. Total cost should be somewhere around $600. Here's another good website.

www.reiderracing.com

I know that you're a ways from Houston, but this is one of the best places anywhere to have it done; 1/2 day turn around/appts.

www.pylebros.com

 

I can attest that there is a big difference between 3.55 and 3.73, so going from 3.08 to 3.73 should feel like adding a supercharger! OK, I'm exagerating, but it should feel pretty good. I've been quoted $1500 parts and labor for front and rear. I'm looking at getting an 02 Screw and having them swap the 3.55 to 4.10.

 

If I have Ford do the work, then will it still void my warranty? Or does it not matter?