I have a 2006 f150 with the 4.6 and 3.55 gears. I want to move on up to 4.88. What's a good brand? And how can I tell if I have a 8.8 or 9.75 rear end. I know all the fronts are 8.8 and read somewhere that 4.6s were 8.8 rear. Thanks

 

Should be a 8.8 since its a 4.6 and really being a truck they are all good... USA standard is Yukon I believe just Yukon rejects which have small blend that don't meat Yukon high standards... Still good gears and ford racing makes up to a 4.56 and are good to use but I believe you're going to want to look into a notched cross pin with a 8.8 an 4.56 or high gearing I know a lot of people with 4.56 choose to slightly and lightly grind the teeth the pin hits since they don't even get used if set up properly I mean we're talking the very inside edge of the teeth... And there's also Richmond gear and proll others I'm forgetting

 

I was researching Richmond. How can I tell if its 8.8 front or 8.8 rear? If anybody has some part numbers I would appreciate it

 

Diff Wizard

This little thing should help you figure it out, if you email Wayne here, he will cut you a better deal and is pretty knowledgeable.

I would look into it tho, I think all 4x4's has the 8.8" front axle, and the 9.75" rear axle, unless its a 7 lug, then it has the 10.5" rear axle.

 

4x4 4.6's have the 8.8 atleast mine does... And all the other that I have seen... Let me know if you find out other wise for sure... I've been debating swapping the bigger rear diff when I swap to 5.4 but the 8.8 isn't a weak rear end at all

 

It depends on what you're building... the 9.75 is a WAAAYY more expensive axle to play with.

and for the OP... why are you moving to 4.88's? I have a 5.4 and 37's and I'm moving to 4.88's, and I'm worried that's too tall a gear.

 

Yea I know and like I was saying the 8.8 can be rather strong... Stangs run them in the 10's with 31 spline axles spoiled and hold up great to 5,000 rpm launches...

 

Unless you're running 37's or bigger, 4.56's are good. G2 or Yukon make a great product.

I was running 4.56's with 35's, and the rpm's weren't too high on the freeway at 75mph.

 

No you will be fine with the 4.88's. I am getting 4.88's done over the weekend and cant wait to have my truck back. I am getting US Gears as that is what the guy who is doing mine recommended. He said he has put them in a couple F150's and has never had any issues with whining or clunking. I was told to stay away from USA Standard gears as they are the cheapest made. This was from two reputable shops that wouldnt even guarantee them enough to install them. This is why you can find them for cheap on ebay. US gear and USA standard are two completely different companies...be careful. But yeah Yukon, G2, and Motive are also good companies that sell gears.

I was told/recommended by more than 3 members to do 4.88's instead of 4.56 with 37"+ tires. They have 37x13.5 Toyo M/Ts and love the 4.88's compared to the 3.73 and said the 4.56's would have been a waste. Plus when you look at all the gear ratio-tire size charts, they all put 4.88's smack dab in the middle of the power band for 37's. MoDy150 is getting 16mpg he said now with his 4.88's with 37x13.5 Toyos. Good enough for me. I just want to save the transmission but if gain some mpg, itll be an added bonus.

 

Mixed driving, city/hwy, were you getting over 260 miles per tank?