hey guys, quick question about the posi in my truck. 2007 f350 cc, 4x4, i have stock rear limited slip 3.73 gear but does the front diff have limited slip also? thanks

 

No, rear only.

And welcome to FTE.

 

so whats the deal with getting posi up front!

 

Well, as far as I know, Ford does not offer limited slip in the front on any trucks and hasn't for a long time.

Unfortunately their limited slip is pretty useless anyway. It's far from "Posi"tive, and that is a Chevy term anyway. They just call it limited slip, and most of us call it limited grip.

I think Ford is concerned about handling and safety with it up front. And they are probably right. You would not want limited slip up front on icy roads for example, because it would break a tire loose on every turn.

You have to go aftermarket if you want a good locker, front or rear.

 

thanks bpound! sorry for refering to the limited slip{ford} as a posi{chevy} how about these saf t track, or sure grip, or even the old twin grip. anyway thanks for the info. i had a 79 f350 and i could swear that thing had front limited slip! it was stock also.

 

It probably did. It was available in the past, but not any more.

 

There are gear based limited slips that you can use up front, Tru-Trac is one. If there is an application for it Torsen is also gear based (if I'm remember right) and would work in a front differential application.

 

Yeah, TracLoc is the Ford term. But in general, a "posi" can refer to any "posi-tive" traction differential. Positrac is a GM trademark.

 

Anyone a big fan of the selectable ones... ARB air locker or the Ox locker? I like the idea of the locking diff but since I use my truck as my daily driver especially on icy roads I dont like the sound of a locker or even limited slip. My current F150 is all open and I can manage it fine on the road and the thing has been awesome off road as well. I am thinking of getting a SD next year, wondering if I should skip the extra charge for LS and just put in a selectable one afterwards?

 

The amount Ford charges is negligible, so I'd go that route, then pay for what you want when you're no longer satisfied with how it works. I ran True Tracs front and rear in another vehicle, in a snow state. There aren't any issues I ever came across with a gear based limited slip. I've heard of poor performance with the clutch based limited slips, but I have had no problems with them either (except they don't work as well as the True Trac).

 

The ford limited slip in my 02 Sd 350 is pretty much useless the way ford sets them up. It acts like an open rear end in the snow . I believe from reading other threads on the forum, they use way too much friction modifier . I am going with an 08 cover soon , and am going to try less modifier than they originally used.

 

Last I knew Ford would offer it only with fleet(large) orders.

 

I thought opens were the best on snow/ice? Unless your talking about just off road deep snow...

 

Opens are best on the ice. Since traction is so very low with the ice, the little bit of bias that a LS would have would cause the wheels to slip together. There isn't enough traction for the LS to work properly. It would cause the vehicle to slide sideways.

Some argue they are better in the snow too, but I guess it really depends on what type of snow. I think that for a truck, some kind of positive traction aide would do better in the snow.

Then again, in the snow I could get out of my dads bronco and watch as all 3 wheels slowly spun in place. I never got along with that truck very well. Only vehicle I could get stuck on a routine basis.

 

Hehehe yeah I hear that... what year was the bronc? My 78 gets stuck on my flat driveway if its slippery. But I attribute that to the old worn out 33x12.5 super swampers and a touchy and sticky throttle on the carb. Got me in trouble once in a parking lot going about 2mph... just kept sliding slowly right into a stopped car about 200 foot away. I probably could have got out and ran up to the car and told em to move...
But my '99 150 even with open diffs handles snow just insane... been through many a storms in upstate NY were the snow was up to the axles and even the body on the road... cruising along at about 15mph for 30 miles to get to grandmas house for thanksgiving. One trip up there thanksgiving week I was hunting out at the farm with the snow just about up to the body... and tried driving over the huge mudhole that even the tractors drive around (thinking it was frozen) and well, it was until I was half way through it and all the sudden a big crash and the truck does a nose dive and snow was up over the hood. Couldnt budge it forward but she backed right out. Folks also say skinnier tires and a heavier vehicle is good in snow too but my truck seems to defy those. My cousins 250 with LS and slightly skinnier tires does ok but is always getting stuck or sliding on the road. He's always been able to get unstuck by himself , except once, at least while I was around. I'll miss the light 150 when I get the SD, but everything else about the SD is better (well except the mpg and turning radius lol).

Still dont know if I should get the LS... I'd love to have one of the selectable lockers so I can go all open unless I am off road.