4.10 open vs other options

[2002sporttrac]

Recently had bearings fail in my 02 Sport Trac with a 4.10 open rear. The 4.10 was an option for this model....i want to replace complete rear end but can not find a used 4.10 in my area. Can i just switch out with a 3.73 from same year model sport Trac ?? If so, what other changes would need to be made? Would the difference in gear ratio affect tranny or motor?

 

[Dweeberman]

If you have 4wd, then the front diff will need to be changed to match the gear ratio of the rear, or vice versa. Also if you are running larger tires, then yes it will create more stress on those components. Now i believe the 4.10 ratio was an option mainly for towing purposes. Since they came with 3.73's as an option as well, you will be just fine with minimal affect to the tranny and engine. Your crusing speeds will be at a lower rpm, but your acceleration will take a small hit, so if you are an in town cruiser, you might see a decrease in gas mileage. If you are a freeway/highway driver, then you might see an increase in mpg. Hope this helps

 

[2002sporttrac]

Sorry, left out its 2wd. I am fine with the change to 3.73's myself. Have found salvaged used for $250-$350. Its a daily highway driver with 265/75/16...but i was looking to put stock 255/70's to increase mph a bit and a smoother ride

 

[Dweeberman]

okay then i think going with the axle with the 3.73's would be a good swap. Especially if you are going down in tire size, then you will be back to where you are now (theoretically speaking of course).

 

[swshawaii]

For the stock Gen 1 ST.

3:73 = 235/75-15 or 235/70-16
4:10 = 255/70-16

http://www.mysporttrac.com/shared/msgboard9e.asp?BOARDNAME=MSG&VIEW=1299293&SUB=1299389

One of many on line tire size calculators:
http://tire-size-conversion.com/tire-size-calculator/

 

[05dakotatrac]

yeh that is stock size tire as i have 3.73 LSD and 235/75R16 stock tires i have since gone up to 265/75R16 tires on 3.73 LSD and it is still functional slower but functional

 

[2002sporttrac]

So can i swap with a 3.73 rear from a 01 sport trac 4x4? Mine is 2wd

 

[429CJ-3X2]

For the stock Gen 1 ST.

3:73 = 235/75-15 or 235/70-16
4:10 = 255/70-16

http://www.mysporttrac.com/shared/msgboard9e.asp?BOARDNAME=MSG&VIEW=1299293&SUB=1299389

One of many on line tire size calculators:
http://tire-size-conversion.com/tire-size-calculator/

Yep. My '02 has 3.73 and 235/70/16. I had to ask in another thread why everyone was talking about 255/70/16 as being the stock tire size.

 

[Turdle]

So can i swap with a 3.73 rear from a 01 sport trac 4x4? Mine is 2wd

Yes.

 

[tooltime]

I have been looking for a replacement 8.8 with disc brakes and at least a 4.10 either open or a l/s for my project pre-runner. Im running nearly 33's right now with stock gearing and I cant stand it. Ultimately a 4.30, or even a 4.56 would be a bonus for the types of high speed roads Im running. My rpm's are much lower than I need. Which as everyone knows, kills motors, transmissions ect. Im willing to do a swap and cash if anyone lives in Las Vegas.

 

[05dakotatrac]

hey OP look for the 03-05 rear end as it has disk brakes and also you have 3 years to play with rather than just 01-02

also a 2nd gen explorer has the same trac with and rear axle as our truck. so a 95-01 expo works too

 

[tooltime]

Thanks, I have been looking expy's too. Just for the sake of stating info; If someone is looking for discs, and or a 4.10 gear, look at the Eddie Bauer Expys, or Merc Mountaineer for your diamond in the rough. That is where you will find what one seeks!