Rear Differential

[Third_Edition]

Hi,

I am new to this forum.

I just bought a 2000 Explorer 3 door sport - it is rust free and runs well.

My problem is that the rear end is not behaving very well and I would like to know my options.

Will a 9" Ford rear fit in here and has anyone done this type of swap?

The 8.8" rear may not be up to the type of use I want this truck to handle.

It also has traction control / ABS - can this be removed?

Your help would be appreciated.

Thanks,
George

 

[CDW6212R]

Hi George and welcome. That 8.8 rear can handle almost anything, but if it's been neglected it needs work or replacement.

The one ABS sensor on it is also the vehicle speed sensor, and it is required for the computer to control the transmission, and for the speedometer. It does not have traction control on the 2000 model.

Any Explorer rear from 1995 to 2001 will work for that 2000 Sport, even the 02-03 Sport and the first Sport Trac have the same rears. The gearing and the diff(LS or not) are the only variances for those.

 

[2TimingTom]

The 8.8" rear may not be up to the type of use I want this truck to handle.

What are your plans? The 8.8 is a pretty strong axle. Some F-150s and Expeditions even got the 8.8 rear.

 

[imp]

@Third_Edition
While it might be possible to set up a "tone" ring in a 9-inch (some hearty soul may even be marketing one), adapting the old monster to an Explorer would be a challenging task, probably involving relocation of the spring mounting pads, as well as correction of driveline angle. Then there would be the issue with brakes: retrofit to discs, what to do about parking brake? The guys are right on regarding the 8.8; it's stout, so much so, that it even survives in aluminum!

I loved the 9-inch during my racing days, because of the simplicity of having a number of carriers already set up in a variety of gear ratios, and easily changing them in and out. imp

 

[koda2000]

Nothing wrong with the 8.8". Adapting a 9" is possible (anything is possible) but a lot of work, or money to get one ready to bolt in (Currie) and not worth the trouble IMO.

 

[Third_Edition]

I think based on what I have heard, it is best to do a rebuild or replace with another the 8.8"

thanks to all for your advice!

 

[96eb96]

What are your skills? If you have access to a good JY just look up your axle code and pull the entire unit. Pull the cover to see it isn't trashed, and change the fluid to 75W140 synth.

If you can rebuild the rear end tear it down, repair and maybe rebuild or upgrade the LS clutch packs.

 

[Rhett]

Something like this (which I think is what 96eb96 is running), perhaps:
http://www.americanmuscle.com/ford-31spline-88-carbondisc.html

 

[96eb96]

Something like this (which I think is what 96eb96 is running), perhaps:
http://www.americanmuscle.com/ford-31spline-88-carbondisc.html

Yep, the price went up but it is a great upgrade, especially if you drive in snow.

 

[Electrohacker01]

why would you spend the money to drop in a maintenance item like a limited slip when you can upgrade to a torsen which requires no maintenance or rebuilding, just regular oil changes?

 

[CDW6212R]

The stock type LS as shown runs about half of the torque sensing True Trac, about $250 versus $500.

 

[96eb96]

why would you spend the money to drop in a maintenance item like a limited slip when you can upgrade to a torsen which requires no maintenance or rebuilding, just regular oil changes?

1) Cost, I paid $220 for it. Jiffy Lube wants $110 bucks to suck out and replace fluid. Also, I'm not keeping this 96 forever.
2) See #1, as a daily driver it lasts 75-100K miles. If you rotate tires and tread is even it may last even longer.
3) Torsens have 0 preload. So, on snow it is an open diff. The limited slip S-spring gives you about 20-30ft/lbs of prevailing torque, even if one wheel is on glare ice. Basically this is a weak locker. There is also the parking brake trick, but if there is really zero traction on both sides, you aren't going anywhere. Also, it is not a locker and both the torsion and limited slip will fail a split-mu test going uphill.

So, from an open, it went from undriveable in the snow in 2wd to not needing 4wd unless there was a hill. 4wd is almost unstoppable. The only downside is on slippery turns both wheels are going to spin, because of that s-spring preload. So you have to drive a bit more carefully. No accelerating into turns.

 

[Rhett]

3) Torsens have 0 preload. So, on snow it is an open diff. The limited slip S-spring gives you about 20-30ft/lbs of prevailing torque, even if one wheel is on glare ice. Basically this is a weak locker.

Can you expand on that a little bit? The Torsen rear was one of the ones I was considering, but now I'm wondering if the Ford racing carbon LS isn't better for me. I need the truck perform in snow, although I always drop into 4x4 anyway...(it's mandatory with an open diff as you probably know).

 

[Electrohacker01]

Can you expand on that a little bit? The Torsen rear was one of the ones I was considering, but now I'm wondering if the Ford racing carbon LS isn't better for me. I need the truck perform in snow, although I always drop into 4x4 anyway...(it's mandatory with an open diff as you probably know).

I'm very curious about this preload thing, the pure function of the torsen means it doesnt need a preload to resist being an open diff. I do plan on keeping my explorer till the day I die (another 40-50 years if I last as long as my grandfather).

 

[96eb96]

Can you expand on that a little bit? The Torsen rear was one of the ones I was considering, but now I'm wondering if the Ford racing carbon LS isn't better for me. I need the truck perform in snow, although I always drop into 4x4 anyway...(it's mandatory with an open diff as you probably know).

It is not a simple answer. If cost is not an option the Torsen is a very good choice too.
A locker locks both wheels, we all know why that isn't ideal.
An open sends all torque to wheel with the least amount of resistance. So, if one wheel is on frictionless ice it will just spin.
The s-spring in the trac-lok acts as weak locker. No matter what, for the first 20ft/lbs or about 10% of the torque of the engine can spin both wheels. Beyond that, So, it may give a bit of advantage if one wheel sits on something very slippery. This is actually a test to see if it is functional, using a torque wrench. I was told by Ford that is what gives it an advantage in the snow. There is a lot of talk about the F150 spring. It is good for a truck in mud or snow but maybe not so great for racing.

From the research I did a torsen needs some traction on the other wheel wheel to function. I don't think a Torsen could ever lock the axles together under any circumstance.
Here is a good page explaining all of them:
https://www.carthrottle.com/post/en...differential-and-whats-most-suitable-for-you/

 

[Electrohacker01]

in my research traction is not needed for a torsen, but it does have some lag before lockup. in fact under traction is acts like an open diff, that's kinda the point

 

[CDW6212R]

I have two rear Torsen diffs now, and I've never had just one tire spin on my Lincoln. They both spin, and it has 3.73 rear gears. The Torsen in the rear of my Mercury helped me to get up many slopes while delivering mail, one rather steep one that had one front tire spinning most of the way up. If only one back tire was gripping(the other spinning), then a single front and rear tire would not get you up a decent hill. I've got two front Torsen's to go into my two Explorers before Winter, and a True Trac for the back.

 

[2TimingTom]

All I know is that my factory LSD on my Expedition only engages both tires in the slipperiest of conditions (like playing around in the snow). In dry conditions, it's an open diff.

In the dry, I point my Explorer in a direction and it goes there (true tracs front and rear). Before I got the diffs, there may have been a lot of wheel spin needed to go somewhere. With the diffs, basically no wheel spin. It just goes. In the snow (on the trail) the true tracs really don't work that great. They are better than open, but it involves left foot braking to help engage that other wheel. In the snow on the street, the true tracs will easily spin both tires (or all 4 tires when I'm hooning).