Rear End Gear CHange

[47CP]

I just made my first trip with the new (to me) van towing the 8000# race car trailer. The 2003 Extended V-10 pulled very well, and towed about as well as my old 2002 F250 did with the diesel before I chipped it.

However, my van has the 3.55 ratio and I think the engine would be much happier with a little more gear...a 4.10 would make cruising at 75mph a lot nicer.

So, to my questions:

-How do I identify the rear end? Will the door code tell me, or do I need the info from the tag underneath?
-Where do I find gears?
-Is there anything needed for speedomeer correction?
-Any other gotchas?

Thanks,

DaveW

[MikeL46]

Any good rear end shop can help you with all your questions.

Expect to pay $700-1200 to change the ratio with the axle in the van, less if you take the axle into the shop.

Mike

[robsd]

Mike,

Not sure why it would be less if you take it in? You mean the whole removed axle? A gear change is an easy in place swap. Depending on the ratios the only thing needed is the ring and pinion. Going from a 355 to a 410 might require a carrier swap. Added cost here. I've done several rear ends in my days and they're not as hard as people say. especially if you have access to a press. Shimming isn't a big deal, start with what you had and go from there.

These days your cost estimat is probably close depending on the need for a new carrier.