i have drove only front wheel drive cars for about the last 10 years. Last summer i got a 2001 f150 4x4. I have 3.31 gears and a open differential. want i wood like to know is a front wheel drive car a open differential ? my last car that i still have is a 96 ford taurus i did real good in the snow (6 inches or less) will my open differential hurt me real bad in the snow? is my front wheel drive taurus a open differential ?

 

Yes, a front wheel drive has an open differential. The reason it did so well was the weight on the drive axle. Your 4x4 will do just fine in the winter. I recently changed out my rear axle, and havent moved the limited slip over to the new axle yet, and it does just fine, no reason to change yet. I just put it in 4x4 when pulling out into traffic, and when on an obviously snow covered road (as needed, depending on curves and speed). I towed a 6000 lb. trailer this weekend through about a foot of heavy fresh snow, and had no major issues in 4x4, just went slow on the hills.

 

would a limited slip make a big difference is it worth what it cost? how much would i cost to put on in? what kind of shop would put on in?

 

Not sure of the cost, but in the past I have had 4x4s with an open rear and with LS. I will no longer buy a vehicle if it doesn't have a LS rear. Note - None have an OE have LS front. With a LS front or with a non-selectable locker, the vehicle will have a tendency to keep going straight even if the wheel is turned. Thats why an open front.

 

Hello chrism9232,

An open differential will hurt in the snow, basically you only have one tire with power. If you can get a good after market LS. I would recommend either a Auburn or Truetrac. The Auburn is better off-road (more aggressive) and the Truetrac is better on-road (smoother) just pic the one that matches your driving needs. You can get it installed at an 4x4 shop and many transmission shops do differentials as well.

 

I know this doesn't help you Chris but, I'd like to mention this to potential new truck buyers who may read your thread title.

Aftermarket LS differentials run between $600 - $1,000 installed.
Ford offers this option for about $250.

There are few true bargains when ordering optional equipment however, this is one.

 

Raoul, I would have to respectfully disagree with your goat herding a$$... err axle..... :P

True the factory LS is only a $250 option, but as with all things automotive, you get what you pay for. The factory trac-loc rear diff is, in fact, a limited slip. However, due to its design, it does not truly limit the slip. Once one wheel breaks loose, the clutches will continue to spin until the cows come home. It's very easy to have one wheel stuck on ice and one wheel in the dry and spin the icy surface until it shines. The factory spec in the shop manual calls for a minimum breakaway torque difference from left to right of a whopping 20 ft*lbs. That's barely enough to be useful on a good day. Sure, a bit of brake modulation can sometimes bring things back in line, but even that's tricky at best. It's just a weak clutch-based design IMHO.

Personally, were I to do it over again, I would pass on the factory limited slip in favor of a TruTrac. The TruTrac, unlice the Trac-Lok, does, in fact, limit the slip of the spinning tire. It's a torque-biasing differential, and it will limit the spinning wheel to a finite ratio compared to the other wheel (generally 3:1). It's a much more robust design IMHO, and they really do make a world of difference compared to a clutch-based limited slip.

-Joe

 

For me it's the only game in town.
You get what you get for $250.

Aftermarket is too pricey.

If Ford didn't offer it, I'd be riding open until the cows came home.

 

so do you think it is worth putting on in i dont drive off road. four wheel drive is just for snow i live in louisville, ky we dont get a lot of snow 10 inchs max on a bad snow storm but i want to be able to get out the is why i got a 4x4

 

Like I was saying, you will be fine in the winter. I live in ALASKA. I havent gotten around to putting my limited slip in the new axle, since I havent felt the need for it, and I've driven in LOTS of snow this year (pulling trailers in the mountains even). I think that for the off-roader, a limited slip or locker is the first addition to install, before tires even. However, just for occasional snow, I wouldnt waste your money.

 

From what I've seen (and the TrueTrac may be different) gear-type differentials work great in situations where both tires are on the same surface because they can transfer torque to the wheel with the most grip (generally the outside). However, in situations where one wheel has substantially less grip, these style diffs operate like open differentials. I've learned this the hard way roadracing because when you hop the FIA curbing, the wheel on the paint when in the rain or if it's in the air will spin as much as it wants while the outside wheel gets no power, effectively stalling all acceleration and spinning for a little when it comes down. Every time I'd hop the curbing in the rain (or hard enough to get one in the air) the car would rev to the rev limiter, leave the slippery surface (or come back down) spin for a little, and send me into a hairy spin.

I prefer clutch-type diffs, especially 1.5 way. While the breakaway in the stock diff may suck, this can be fixed a little by adding less limited slip additive (mine hopped the inside wheel on tight turns with not enough additive, meaning it's got more than 20lbs of breakaway) or reshimming the clutch packs.

 

As far as everyday driving on ice/ snow, think of it at the extreme... would you want a fully locked rear end when you are turning on ice? It would allow the rear axle to break traction faster, causing easier loss of control. Sure, you would be better off when trying to go up a hill, or accelerating in a straight line, but would be detrimental in turns. I would rather have a less aggressive lock up on ice.

 

Yes, you are correct in that they can and do freewheel when there is no resistance on any one wheel. I've even seen them reverse the direction of an inside rear wheel when it lifts braking deep into a tight corner. That's part of what makes them ideal for the front axle on our trucks, and why I like them for a daily driver. Very few people will ever hang a wheel in the air driving back and forth to work, so that's a non issue. (and if you DO hang a wheel on the way to work, I want your job!!)

For low-traction conditions, e.g. one wheel on ice, one on dry pavement, heading up-hill, a little bit of brake modulation, and you generally get limited to about a 3:1 spin to traction wheel ratio. That's way more than enough to drive out of most situations, even with one wheel in the air. The trade-off is that you get a reliable, smooth-acting limited slip for the other 99.9% of the time.

So what you're saying is that forcing one (or both) wheels to slip on a corner is better than allowing slippage?? The original poster asked specifically about driving in snow. IMHO, Forcing it to break both rear tires loose with an artificially tight limited slip is just asking for trouble.

-Joe

 

Ah, you twist my statement a little. You're not forcing them both to spin unless you want it to (or don't have a choice). By using both tires, you're increasing the amount of friction available for forward movement.

Correct me if I'm wrong, but if you have a 3:1 slip to grip, you're sending 66% of available power to the wheel that doesn't have grip instead of only half. In addition, that spinning wheel is digging a deeper hole.

Another thing is what you're willing to put up with. The "best" thing for traction would just be a locked diff, but I don't know of many who will put up with one (or trust their axles on dry pavement with one). A gear-type diff's greatest advantage is it's invisible until it's needed.

Yes, that diff will work great for most situations, but my personal preference is a clutch-type because it drives both wheels mostly equally. Most of my experience with diffs, however, is road racing, so YMMV.