Limited Slip, ford explorer, mercury mountaineer, lincoln aviator,

I think ford only offers one choice, their "limited slip" whatever it's called.

Sun, 14 Feb 2010 18:08:01 -0700 Ashton Crusher wrote: | On 14 Feb 2010 19:58:54 GMT, Deadeye wrote: | |> |>Hi, |> |>All the same car. All offered in AWD. What is the |>best choice for positraction/limited slip rear diff, |>with the AWD drive train? | | I think ford only offers one choice, their "limited slip" whatever | it's called.

Maybe there is no such thing... for these cars

That's also possible. Some of them simply use the ABS/stability/traction control systems to create an electronic "limited slip".

On the Ford E350 van electronic stability control (ESC) and limited- slip axle are conflicting options, you can't have both.

ESC has been standard on the showroom E350s since 2006. But they have a "commercial" version where ESC and llimited-slip axle are options but you can't install both. I think the commercial vans are available for fleet buyers or volume buyers like conversion van companies.

ESC will be a federal mandated standard for the 2012 or (in some case)

2013 model year. So I think it fair to say the the limited slip axle is obsolesent.

Why would that be? My 2009 F150 has both.

Ed

Possibly for the same reason that you can't get the upgraded radio package on some models without getting the heated seats. It could just be marketing.

--scott

Look on page 3, it says Advancetrac is n/a with limited slip axle:

8.pdf

I don't know why they do this. Note this is the commercial spec. and they will do about anything that's legal to get a commercial contract.

>

Likely the ESC and the limited slip would be fighting each other in low traction conditions. You don't want two separate systems trying to control the same event (rear wheel slip) it just makes things more difficult. Likely if you have ESC there's also "limited slip" capability through brake application on the low traction wheel, but that's just a guess on my part.

nate

The user manual for the Ford E350 indicates that you may need to turn ESC off if you are stuck in snow. There is a woman in my vanpool has a new Honda with ESC and her user manual says something similar.

Makes me think that turning ESC off may engage some sort of limit slip capability that's not there when it's turned on.

On the Ford E350, ESC comes back on automatically if you exceed 20 MPH or restart the vehicle.

>>

My 2009 F150 has the regular old Ford variety of a limited slip rear axle. It also has ESC and traction control. It does not have the sort of system that uses the brakes to simulate a limited slip differential. It controls slip by limiting engine power. I have been in several low traction situation so far. I can confirm that the limited slip works as well (or poorly) as with previous Fords, and that if you are in a really low traction situation, you have to disable the traction control. With the traction control on, you cannot do the sort of mud slinging that is sometimes necessary to get moving in a really muddy field. However, once the traction control is off, the truck acts just like older ones do.

Before the F150, I had a Nissan Frontier that used an electronic limited slip arrangement. It used the ABS to selectively apply the brakes to spinning wheels. It worked very well most of the time. Of course on really slick surfaces, it was no better than traditional limited slips. It just gauranteed both rear wheels would spin...

Ed

So, your claim that you have both is not based on a written list of options for the vehicle?

You are making this claim because of the way your vehicles behaves?

Is that correct?

Do you have Advancetrac with RCS? That uses both engine power and the abs system to provide stability..

My window stickers says my truck has "Advancetrac w/ Roll Stability Control." It aslso lists 3.73 Ratio Limited Slip Axle. If you want to see an example of an F150 with Advancetrac and a limited slip axle, look at

(not my truck).

Yes

Yes

In low traction situations I don't believe that the system is doing anything with the brakes. Perhaps the brake system only comes into play as part of the roll stability control. Or maybe I just don't "feel" anything happening with the brakes. I definitely have the

3.73:1 Limited Slip Rear Axle as well. On really slippery surfaces, both rear wheel spin, the "slip" light comes on, but when you press the accelerator harder, nothing much happens unless you turn the traction control off. For my Nissan when on slippery surfaces you could hear the ABS pump kicking in and activating brakes to selectively lock wheels. I get none of that with the Ford (but if I lock up the brakes on a slipepry surface I can hear the pump).

Ed

The specs for the F150 allow Advancetrac and limited-slip axle.

But. the E350 specs don't allow the combo, I posted the specs earlier.