8.8" 3L73 rear axle

[TheBeater]

I have a 93 ranger 4.0L V6 2wd with auto transmission. My rear axle is shot so I ordered one from a local salvage yard. I have the 8.8 with 308 gears, open diff and 10" drums...I ordered the same rear axle out of a donor truck with 64k miles. They delivered it free of charge to my work address.

After I brought it home I wiped off the grime off the tag on the diff cover only to discover that it is a Limited slip rear axle with 373 gears. It is still the 8.8 with 10" brakes, so it should bolt up no problem.

I'm assuming they simply sent me the wrong one, which means that I have no idea how many miles the donor truck had, however it does feel good. I haven't yet pulled off the cover to see what it looks like inside.

Other than the speedo being off (I used the calculator in tech section to determine how much off it is), are there any other issues I could run into with this install? I know I will have better low end torque, worse fuel economy, and more traction... For the kind of driving I do with this truck (it basically hauls my mountain bike around on and off road and in the mountains), I think this is probably a step up over the open diff with 308's.

 

[85_Ranger4x4]

Actually with moutain driving it will probably improve your milage. My parents '94 Explorer with 3.31's spent a lot of time/effort time trying to find a decent gear when we took it out west.

 

[dangerranger83]

I have 3.73 gears with posidrive and they are great for pulling and towing but it doesnt make my truck a speed machine. My trucks speedo reads 5 slow and it has its original front axel on it, which tells me that 3.73 is the original gears for mine. Rear end blew up a spider gear 4 years ago.

 

[Fx4wannabe01]

question of the hour.... what size tires?





I find the 4.0 ohv and up to 33's with 3.73s is a pretty zippy peppy little engine. You'll likely get better mileage all around. Vastly improved in the city and minimally improved on the highway. She's in her powerband now at 70ish rather than lugging in 5th and frequently driving in 4th. Of course...al lthis depends on what tire size.

 

[TheBeater]

I'm still rockin the stockies. 215/70-14 touring tires. Since I do so much off road mountain pass roads, I have to upgrade tires anyway, so I could go up in tire size...but remember, this is a 2wd and sits a bit lower the the 4wd (i'm assuming but im not ranger expert)

 

[scotts90ranger]

look on craigslist for some 235 75 15 tires and wheels for cheap, you shouldn't have any trouble fitting them. Look for tires from an explorer, jeep or a handful of other vehicles. That tire size should be a very good match

 

[Fx4wannabe01]

man....I'd jump that up a couple sizes for the hell of it. lol. With that small of a tire(25.9"), You are just a skotch bigger than my little brothers slammed 2wd 4cyl w/ 3.73s(245/45R17 = 25.7"). He sees EXCELLENT mileage. Of course..he is a 4cyl. lol. I vote you'll see some good mpg numbers and the truck will be pretty fun in the city.

Have you though about upgrading to a 15" wheel for more tire options? I'd lean towards a 225/75R15 or a 235/75R15 if you can fit it.

 

[dangerranger83]

Im running 235 75r15 tires. Dont have the money for 33's (like my current motor could turn them LOL) plus my tires are still like-new.

 

[TheBeater]

Thanks for all the info, i'm about due for tires anyway, so i'll probably look for 15" wheels and go with teh 235/75-15's.

On a side note, I am prepping this "new to me" rear axle and found that one of the axles is shot. The seal was leaking and the the bearing badly wore the drive shaft. Well anyways, will the axles out of my 8.8/308/10" brakes be a direct swap in the new 8.8/3L73/10"? I suppose I could just pull one out of my old axle and check...

 

[Beanmachine7000]

3.73 + 235/75-15 + 4.0L =

Seriously, that's what I have and I beat on it and never get less than 16 mpg (20-21 on the highway [55mph])...

 

[dangerranger83]

I'd be happy with 16mpg with on the high way or city with my current motor in my truck. It gets 14 mpg on a good day. But it will be gone real soon.

 

[nooberiffic]

If your original ratio was 3.08, and the new axle is 3.73, you are going to have to switch out the gears in the front end too.

 

[maroon ranger]

So...about your lookin around for wheels and tires. I got 4 235 75 r15 bfg at ko's on the ranger deer hoof rims. Two are about 30 tread life and the other two have around 5000 miles out on them. I guess pm me if your interested!

 

[TheBeater]

If your original ratio was 3.08, and the new axle is 3.73, you are going to have to switch out the gears in the front end too.

2wd

 

[MAranger]

I did this same exact swap, though I have swapped the front in too. 3.08's to 3.73's was the best $200 I ever spent on this stupid truck.

I didn't notice a loss in mileage. Huge gain in sack!

Funny tho, with fresh brakes on the 3L73, it won't do the brakestands I could do with 3.08's open, with shit brakes.

I try to not spin tire now though, after ruining a set of BFG's in 17k miles.

Now that I've done 3.08 to 3.73, I want 4.10's lol.