HELP!! FRONT DIFFERENTIAL Blown 4.8is

[nitrogass2000]

UPDATE:

I just wanted to let everyone know that everything worked out. I used BOTH front and rear diffs from a 2005 3.0 in my 2004 4.8is i also had to use the 3.0 drive shaft and the 3.0 rear Axles.

Car drives wonderful now has a little more kick, fuel consumption is fine no crazy increase, speed appears to be fine as well (even thou i think my x5 shows 5 miles more speed than actual speed)

Overall i am so happy everything worked out and i love my x5 now! Its been 3 months took a 4 hour trip with it and everything is great!

I just also fixed my FOB dead battery replaced it with a new one from cvs and did the reinitialization and it works!!! saved me a ton of money on a new key. Right now getting ready to paint my steering wheel trim back to black. Overall we are happy right now!

[TiAgX5]

Good to hear.

Bet it comes off the line much harder with the lower gears.

Less stress on the trans/tq converter/x'fer case is an added bonus.

[jdstrickland]

I think the 3.0 uses a 4.10 gear, and the bigger motor takes something like a 3.83 gear. Whatever. The point is that the new gear will make the engine turn faster at the same speed -- if you were turning 3000 at 70 before, then you will be turning something like 3500 at 70 now. One can work the math if they wanted to, the point here is that the engine will be faster now than before. You will have more power off of the line, but the max RPM will be hit at a lower speed, likely still a speed that exceeds the limit.

If your speedometer is fast -- reports 70 when doing an actual 60 -- then you fix this with a taller tire, for example if you have a 245/60 now, go to a 245/70. Or, if your X has a set of 18" wheels, then buy a set of 20s. This is a calculation also. Pretty simple, really. You can go to a site such as www.tirerack.com and use the tire size calculator. Plug in your current tire package, then plug in some alternatives and the calculator will tell you what the affect on the speedometer will be.

In a tire size, 245/65x17, for example, the 245 represents the tire width, 65 is the sidewall as a ratio of the width (245 x .65 = the sidewall height), and 17 bis the rim diameter. If your speedo was accurate and you wanted to upgrade from a 17 to an 18 or 19, then you would reduce the 65 by 05 for each inch increase in the diameter to keep the same overall diameter for the width. A 245/65x17 and a 245/55x19 will give the same overall diameter because as the wheel size increases, the sidewall decreases by an equal amount, leaving the same overall diameter.