I think my 2WD 99 F250 SD has the Ford 10.25" rear axle. Definitely with an open diff. It sure is not happy with ice, snow or mud so I think I want a locker. It looks like I can't take the cheap and easy E-Z locker route with this axle but would need a full diff? Has anyone else had luck with any ls or locking rears on a 2WD with the same axle?

 

Looks like a lock rite or Powertrax No Slip can be had to replace the innards of an open 10.25" rear. Any experience with either?

 

Your 99' should have a Sterling 10.5" however most 10.25" and 10.5" parts are interchangable. If you want a "locker" I would look at an
E-locker from Eaton or Auburn.(Flip a switch for full locker, turn of open diff) If you want a "Posi" the Detroit Truetrac made by Eaton is a very popular unit in SDs.

 

I don't know man, theres not much you can do with ice. Maybe i'm wrong, but in ice I would prefer an open rearend.....which is TOTALLY different than what I would want in mud & deep snow and TOTALLY different than I would want in 99% of other conditions. This is where an ARB or E-Lock sounds like the smart way to go and the way i plan to go with my SD. Being able to change in a second depending on conditions would be a major plus.

The reason I say this is, with an open rearend, the outside wheel is allowed to turn faster than the inside wheel(no bind). "TURNING" on an icy road where you want as many tires "planted" as possible, I think it is important to have both wheels working independantly on turns anyway. Going straight I think it would be different....but in the mountains, you don't go very long without turning.

If you had a locker in the same situation, the inside wheel is MADE to go faster than the outside wheel and actual makes it kind of spin and may break the rear wheels loose, thus possibly spinning the rear around. Again, my theory is to have as many tires "planted" as possible.

I came up with this theory after I moved to the mountains in east Tn. almost 4 years ago. I haven't had my SD long enough to drive it on icy roads, but i've had a F-150 FX-4(which is now for sale) for a couple of years and with the factory open rearend was able to go up a local rural mountain (2 years ago) easy on all those sharp turns going up.....even though a pretty stout bowtie(conflict of terms?) 4x4 with lockers couldn't make it but 1/4 of the way before having to give it up.

I would like to say it was just my superior driving skills, but the other 5 or 6 trucks I was with also had open rearends and made it all the way up and more importantly all the way down without going off the side of the mountain, unlike the stout bowtie that had to give it up long ago.

Anyway, an ARB or E-Lock is on my Christmas list.

 

I am pretty familiar with the different types of locking differential designs. I am not familiar with the axle on my truck! Great info that it is a 10.5" Sterling. I like the economical and easy to install locker kits that replace the spider gears in the diff. I've been in a full size van and a vintage Galaxy where there seemed to be no ill effects (for a "car guy" anyway.....) from that kind of a locker. But locker choices seem limited. For example, the Reider racing site has a Lock Right locker for a Ford 10.25" and a GM 10.5". I'll have to look for a sterling or ford reference on a 10.5"..........Anyone put a locker in a 10.5"? The E lock sounds nice but doesn't sound like the most economical path to traction!

 

Well, remember you get what you pay for. Personally I wouldn't put one of those in, as I bought a truck one time that had one of those in it. I killed it fairly easy in a mud hole in the 1st 6 months I owned the truck.

 

I see the Eaton Posi for a 10.25/10.5 as a 30 spline but other lockers show 35 spline. Any spline count confirmation or other aftermarket experience?