How can i tell if i have the 8.8 or the 9.75 rear end in my truck. And can the 9.75 rear end handle more weight than the 8.8 in the box, or more tonque weight. And I think my truck is rated to tow 7800 lbs, but i could be wrong.


2000 f150 Short Box Step Side
5.4L
17in rims
Axle Code=19
GVWR=6300
Front GAWR=3680
Rear GAWR=3550
Class III Hitch

 

Since you have the 5.4, you have the 9.75, but with the 19 code, that means it's a 3.55 OPEN diff..... Another way to tell is just by looking at it. The 8.8 is basically round and the 9.75 is kinda oval looking. The 9.75 also has 12 bolts compared to 10 bolts on the 8.8.

Not sure on the difference in ratings, but I'd guess that the 9.75 is stronger then the 8.8.....

Good luck!

Mitch

 

What does open differential mean. Is that good or bad

 

Open differential means it is not a locking or limited slip type of differential. 3.55 gear ratio is not ideal for towing, 3.73 or 4.10 would be much better.

 

That sounds like a question my wife would ask!

 

I've learned from experience the safe response is to refuse to answer this question.

 

Check out this article on the differentials.

 

Lower gears are fine to tow. My towing package came with 3:55LS and it tows my hefty toy around no problem.

 

3.55's are higher gears that 3.73's/4.10's!!

The lower the number, the higher the gear.