Where could i go to get a set of 3.73's for my rearend. I would love the added mpg. If anybody knows where i could get them or would like to trade their 3.73 for my 4.10's let me know.

jay

 

While you are looking, you better think about regearing the transfer case also since your sig says you have a 4x4. You can't just change the rear end.

 

What??? You will need to regear both front and rear diffs, but you really lost me on this one.

 

You will need to change the front axle gearing to match the rear since you have a 4wd. Can't have a 3.73 in the front and a 4.10 in the rear or the transfer case will take a dump.

MikeyB

 

Shoot how about some 3.55 or 3.23 gears? I am waiting for the AMM ARB Locker to come out so I can change out my 373's after warranty expires on my 05.

Joe

 

You don't need to re-gear the transfer case...but you do have to change the gears in both the front rear and the back rear so they are the same.

 

OK,

What is the front rear and the back rear?

 

You have 2 sets of drive gears in a 4wd. One set in the front differential, the other set in the rear diff. You can't miss-match them or the transfer case will destroy itself when you shift into 4wd.

 

If you have to pay to change the gears over, I'd take a WAG that it'll cost upwards of over $1500. You'd have to drive that truck a zillion miles for any fuel mileage savings just to pay for it.

Unless spinning the engine 200-300 rpms faster really bothers you, I wouldn't bother.

 

Yup, I meant front diff instead of transfer case!!! It was very early in the morning (or very late at night depending on your perspective)!

Anyway, front and rear diffs have to be the same. Dodge quoted me $1800 to do a 2001 about 6 months ago. That is 1 of the reasons the new dually is on order ... wanted something beside 3:55s for towing.

 

I'll second that. The cost of replacing front & rear diff. gears would easily be more that $1500.00 and it would take a bit of driving to get it back. If money is no object look into U.S. gear overdrive before the transfercase or a Gear Vender unit. I just think that that amount of money would be better spent on other engine mods to help performance and maybe economy as a byproduct. I ran a chevy gasser van with a U.S. gear set-up (20% overdrive) with a 4:10 ratio to L.A., Midnight run no a/c going 70MPH....14mpg
Made the same run two days later in the summer heat without overdrive engaged and a/c on.....14mpg. After that test I had different thoughts as to the effectiveness of the overdrive units. I feel that the additional weight and drag from the gears in the U.S. gear did nothing more that lower my RPM. And they do make a little noise when engaged.

 

Well, I will throw one in there for you....My best friend. His dad owns a 85 Blazer, since new. We have ABUSED the heck out of the truck, blown up EVERYTHING in it, once it was put out for the ranch. Well, we blew up the rear end...diff and gears, 3.73. Well, his Dad was tired of replacing all of the parts we ere blowing up,and he had a diff and a set of 3.08 gears out of anotehr 10 bolt laying around, BUT not for the front. So, we installed them anyway. Stock 3.73 in the fron, and now he have 3.08's in the rear. The Blazer NEVER comes out of 4WD, but is ALWAYS driven on loose soil (dirt, mud, gravel) been around 12-13 years or so since the install, and we have even blown up another motor since the install. BUT, no problems with tranny, rear or transfer case since. Yeah, funny to drive (feels weird with the wheel spin from the front and not the rear. BUT , it has worked, and it is NOT EVER driven on solid ground. But, I did just want to throw in a situation where it HAS worked (mix matching front and rear gears)

 

It has survived this long because of the lack of solid traction ie; pavement & concrete. I like the ranchers fix. No new parts needed and it still works

 

The only reason it has worked is because the front can spin. If you put it on a hard surface, it wouldn't last long.

 

how do know if my truck has 3.73 or 4.10