Bought a pre-owned 2000 XLT. How do find out if there is limited slip in it? Are there codes on the axle or VIN?

 

hose down your driveway then stomp on the gas. I found out mine didn't have limited slip when my right rear tire was the only one in the mud and I couldn't move

 

A for sure method to check if your vehicle has a limited slip differential is to put the rear axle on jack stands, engine off, place the vehicle in neutral and turn one of the rear wheels by hand. If both wheels rotate in the same direction you are turning them then the differential is a limited slip type. If one wheel rotates in the opposite direction as you are truing then the differential is a non-limited slip or AKA open differential.


Also, all axles should have a small axle tage on one of the diff cover bolts that will have the axle ration and a code. If I have the correct information the axle codes are as follows for the 2000 Excursion's 10.5" axle:

3.73 open diff. = EGJAB
3.73 Limited slip = EGJAC

 

Thank you very much to the both of you. Although I like the wet down the driveway idea, my neighbors may not...

 

Keep in mind that limited slip differentials operate just as they are called, they limit most of the slip between each rear wheel. Remember when a vehicle makes a turn the inside wheel must rotate slower then the out side wheel and the limited slip diff is designed to allow this. This means that it is very possible to get one wheel spinning on ice or mud while the other is on dry pavement and not spinning. The limited slip diff is trying to direct drive shaft torque to the non spinning wheel but the wheel in the mud is spinning way too fast. My point is just trying to spin the rear wheels in the mud or on a dirt road is not an absolute method to determine if you have a possi diff.

But if your vehicle had a Detroit Locker or a sold spool differential then the wet drive way stunt would work.

 

KPO - thanks for the help. I had the tire guy spin a rear wheel during my tire change yesterday. It's an open diff. You sound like you know what your talking about so I'll ask you this. My truck will probably never see dirt unless it is an improved trail or dirt road. My biggest low traction situation is snow. (I live in North central Massachusetts) Do you think installing a locker is worth it when I have 4 wheel drive? The idea sounds cool (to have a rear locker)but would you say it's worth it to install one? This question is open to others out there too.

Since we're talking axles, what purpose does the selector on the front axle serve. What is the purpose for both AUTO and LOCK? Won't AUTO lock 'em? Or does LOCK mean that both wheels will always turn at the same speed? The manual is useless on this subject.

Thanks
KEN

 

Good questions Ken, The answer to your first question is my personal opinion. If you want limited slip diff action on your 2000 Excursion I would just go buy a limited slip carrier from the Ford Parts Department or may be all you would need is the LS parts to install. Avoid the Detroit Locker diff for your every day drive vehicle because they are harsh. The Detroit Locker is a ratchet style engagement unlike the spring loaded clutch disc or cones of typical LS differentials.

This means that when you take a turn in a vehicle with a Detroit Locker one wheel will totally disengage until the vehicle is going straight again and when both wheels return to the same speed the disengaged wheel/axle will snap back into drive making a big clunk sound. I think this type of diff is best for off road use only or installed on a project vehicle (weekend driver). Also, I don't think there is a Detroit Locker available for a 10.5" differential like all Excursions have.

As for your second question yes, the manual is useless but you can thank the engineer who had the common sense to add manual locking hubs because the shift-on-the-fly 4x4 system sucks. The vehicle I had prior to my 2000 Excursion 4x4 was a 98 Ranger 4x4 which does not have manual locking hubs and in South East Michigan we get big snow two or three times a season so the first day we get a big snow fall my *****-on-the-fly system took a dump. The problem is with the vacuum operated 4x4 hubs. The hubs have two large "O" rings that seal in the vacuum to lock in the 4x4 action, but when these "O" rings squeal and wear out the hubs never engage.

All 4x4 Super Duty trucks (including the Excursion) have the ability to over ride the vacuum operated automatic feature if it fails like the Ranger. Although, this is very help full it can be problematic because the 4x4 front axle is always rotating if the vehicle is moving or until you switch it back to Auto. Suggestion: You should try to switch your hubs into Lock and out several times through out the year to free them up because they tend to stick in position if not used for some time. Also, try to drive your vehicle in 4x4 once a month for 10-15 minutes to keep the front diff and seals well lubricated. The front diff does not rotate when in 4x2 High and if only engaged two or three times a year for heave snow falls the diff lube tends to run off all the important parts creating a rust zone just above the gear lube fill level.

You da monsta.

 

All good advice, KPO, except for the bit about installing a Ford LS unit. The Ford unit is weak. I've burnt up several in my life. Well they don't literally burn up but they stop being limited slip and start being unlimited slip. The LS in my Excursion went out at 10000 miles.

So I can't recommend that anybody install the Ford LS unit.

Another correction to your post would be about the locking differentials. They have evolved tremendously from the abrupt enagement you describe. There's even a new one called the "No-Spin" that does not jerk at all when it engages. When the LS in my Excursion goes out again, after the warrantee is up, I'm putting in a No-Spin.

LS units are inherently problematic. Lockers are less trouble.

Steve

 

Interesting, I was not aware of any advances in Detroit Locker design. My understanding of them comes from what I have read about the 9" verity used in 1966 Shelby Mustangs. Although, I'm aware of some of the more modern and expensive LS differentials I still don't know what is available for the Excursion's 10.5" axle. Can you get this "No-Spin" style differential to fit a 10.5" axle?

 

Will it hurt it to drive with your hubs locked all the time? I do not have automatic locking hubs. I was wondering if i left them locked when i might be in a 4x4 situation?

 

yes.
that's why they put the option on there.

 

do you have a better explanation?

 

I would guess there is no problem with leaving your hubs locked in 4x4 all the time depending on the type of 4x4 system and make of your vehicle. The main advantage for switching the hubs to 4x2 is economy. As you know in 4x2 the front axles are not turning nor should the front drive shaft be turning. But, I think some of the old 4x4 vehicles did not recommended driving on pavement or high traction surfaces in 4x4 because making turns would cause the front end to bind and hop.

Try to find an old owner's manual or just use this rule of thumb that I use for basic 4x4 vehicles (not vehicles designed as AWD):

- If on dry pavement or a high traction surface don't use 4x4 when making sharp turns.
- If you can safely drive over 50mph on any surface then 4x4 is not required.
- If the front hubs are locked in 4x4 all the time just make sure the transfer case is in 4x2 so it's not driving the front axle.

I try to drive a short distance each month with my Excursion in 4x4 to keep the front drive line working correctly but I must turn it off to make sharp turns or turn into my drive way. My past Ranger 4x4 system would bind up solid trying to turn into my drive way. I had to back out and switch to 4x2 when on dry pavement.

 

yes that is a much better reply. sorry Jalawso, i thought the rest of my post made it... Ditto to what KPO said. my old '82 3/4 chevy plow truck would do the same when making turns on high traction surfaces. kept ruining u-joints (on the axleshaft) Why would you want to keep the locked all the time anyway? If you really want to go "high speed" an want the option to lock but don't want to get out to do it. Look into 4 wheeler mag. They have all kinds of stugg advertised that will allow you to lock 'em manually (kinda) but from inside your cab.