I plan on buying a new 2003 F150 4x4 XLT Xcab, probably with the 5.4L engine, and the 17 inch wheels, and the 3.55 rear. I have researched the board as to the pros and cons of the Limited Slip option, but still have some questions. First, I tend to be in the camp that I feel control of the LS on ice is up to the driver. But, what about maintenance. How many miles can I expect from the LS without reworking the discs? Can I still use synthetic lubricants? Under normal driving conditions would I expect more 'problems' with the LS because it has more moving parts. I think I will be keeping this truck for 150Kmiles, and I don't want to be putting money into the rear end, especially since I am going for the 4x4 option. Oh, the reason I want the LS is because most of the time I have no weight in the bed, and I want better traction on wet roads, starting up hills that are wet, etc. Also for those days when you have ice and snow, but the roads have been plowed and are relatively clean, 4x4 is too much, but LS would be just about right.

 

You should be able to go the 150K miles you expect without touching the LS if you take care of it. (ie: replacing oil if axel is submereged in water) Also if you don't hot dog it all the time or put some crazy multiple power adders like nitrous with a blower; you will also last a long time.

Ford ships it with a synthetic lubricant already. (at least the new ones, a Ford tech told me it looks rust colored like there is a problem with the axle when you first drain that oil, even though no problem exists.)

Anytime there are more moving parts, theoretically there could be more problems, take care of it and it should be fine for the length of time you plan to keep the truck.

On a side note, GET the LS,... IMO. I have the 4X2 with a 5.4 and I can spin the tires at will, stock. And during turns I can get the inside tire to chirp as the clutches are trying to grab as much as it can and get me as much traction as it can get me.

Good Luck,

Brian

 

The Ford factory LS is not very good but certainly better then an open rear. Go with the limited slip.
Mine was done after about 70,000 miles but that does not effect the working of the rear. It then works like an open rear. At that time you can decide to rebuild the Ford unit or change to a much better aftermarket LS.
I think synthetic fluid is the best thing you can do for your LS. Also never forget anti-friction additive.

 

Absitivly, posiloutly GET IT. No question.

 

I would recommend you get the LS. Three Wheel drive is better than two. If you are thinking about it then you will kick yourself when you need it and it's not there.

Regards

Jean Marc Chartier

 

For what it costs around $250, it's a bargain. I'm very happy with mine and will never buy another rear drive vehicle without it.

 

I would definitely get a LS. The stock one is cheaper but the clutch pack is prone to wearing out. An after market LS, I think Auburn and Eaton are the only ones available will cost you more, about $650-$750 installed. The later is more heavy duty, last longer and generally limits the slip much more effectively.