I'm sorry, but lately I've seen alot of debate about whether or not front differentials on F150's are LSD or open. Well I just went out and checked mine, and it definately does not have a LSD front diff (it's a 4x2)

Seriously, even though it doesn't pertain to me, I still had to check out reliable sources, so I pulled up the FoMoCo service manual for our trucks. Here's what I found:

I know this does not come out right and say it is not LSD, but if you notice the specs for the rear diff, it mentions the Friction Modifier. But nowhere in the specs for the front diff does it say anything about Friction Modifier. In addition, I thoroughly looked through all pages in the manual about front and rear diffs; there are lots of pictures of the diffs being torn down, but nowhere is there any reference to the front ever being LSD. For example, for the rear diff service procedure, there are actually 2 different procedures (one for LSD and one for non-LSD). But for the front, there is just 1 procedure (obviously for non-LSD, as all front diffs are).

Anyway, just one of my pet peeves lately, seeing this debated soo much with so much certainly by both sides...

 

I haven't seen any of the debates that you mention, but this one is easy to settle. The following method will work for any vehicle axle, front or rear.

Jack up the axle in question so both tires (L & R) are off the ground and rotate one of the tires by hand. If the tire on the opposite side of the same axle rotates in the same direction as the one you are manually turning then it means you have a limited slip differential. If the opposite tire turns in the opposite direction it means that you have an open differential.

But you are correct. No primary RWD Ford vehicles have any type of traction assist differential in the front axle.

 

You do not need to have it jacked up to find out, you can simply spin the cv axles by hand and the opposite side will spin if not locked in 4wd.

 

Is it worth getting a front limited slip?? will it help or hurt off road action???

 

Absolutely. An 8.8 is a weak front so I would not look at any type of electronic locking diff if you want to keep it, instead take a look at the Detroit Truetrac. The truetrac is a gear driven LS as opposed to clutchdriven, clutchpacks wear out over time (driving on pavement). The truetrac will be close to a locker and will still behave well on the road.

 

no F-150 that i know of ever had a LSD from the factory,

 

Actually, I had the option of ordering both front and rear Limited Slip on an F-150 - but that was back when I ordered my brand new 1995 F-150. (I just got the rear.) A friend of mine had a 1980's vintage F-250 with factory front and read LDS's and used it as a (snow) plow truck. He said it was the most bizzare handling truck in the snow he ever drove.

 

You do not want to add a lock to our front diff's unless it is an air locker. Because if we have a locker front diff and the IWE's fail and engage it will be a p.i.t.a to steer with a solid front end, just ask anyone who has drive 4wd with lockers front and rear it doesn't steer that great.