rear diff fluid
 

well im thinking about changing my diff fluid to amsoil but i have no idea how to do it or what kind of oil it takes... any suggestions

Yours takes 80W-90 rear axle lubricant. If you have Traction-Lok limited slip, you should add Ford friction modifier to prevent chattering. Some synthethic makers say you don't need the modifier with their oil.

To change it, you have to pull the diff cover off to drain the oil, then clean and reseal the cover joint and add fluid up to 1/4" below the filler hole. It takes roughly 2 1/2 quarts.

Edit:
What he said

Rand

If you get yourself a little hand pump it will be a lot easier to get the new oil into the differential.

Amsoil sells a pump that fits right on their bottles and makes it really easy to get it in. the pump is $11.

as far as the fluid, it is 80w90, and depending on what version of the gear lube you get, you may or may not need friction modifier with the LS. even so, AMSOIL reccommends the slip lock additive if you do get chatter

ill put in a break down of the lubes in just a minute here

SAE 80W-90 Synthetic Gear Lube : $7.40 qt

High quality replacement for applications specifying SAE 80W-90 conventional gear lube. Synthetic construction provides improved cold flow properties, high viscosity index and heat resistance. Contains an over treat of high quality additives, exceeding the minimum standards. Provides excellent wear protection and long equipment life. Performance specifications include: API GL-5/MT-1, MIL-PRF-2105E, GO-J, SHAES 234 (Eaton PS-037)


SEVERE GEAR 75W-90 : $9.25 qt

Specifically engineered for high demand applications, including trailer towing, heavy hauling, 4X4 off road driving, commercial use, and racing. Superior lube "film strength" combined with extra additives protects gears and bearings from scoring and wear. Resists high heat and possesses excellent cold flow properties. Performance specifications include: API GL-5/MT-1, MIL-PRF-2105E, GO-J, SHAES 234 (Eaton PS-037)


Long Life 75W-90 Gear Lube : $7.70 qt

Specifically engineered for extended drain intervals up to 500,000 miles as set by equipment manufacturers for over-the-road trucks and heavy equipment. Prevents wear and improves equipment life. Excellent "All Season" summer and winter performance. Outperforms all conventional gear oils. Also excellent for passenger cars and trucks. Compatible with most limited-slip differentials. Performance specifications include: API GL-5/MT-1, MIL-PRF-2105E, GO-J, SHAES 234 (Eaton PS-037)


Slip-Lock Differential Additive : $6.75 btl

Formulated with advanced friction modifier. Designed to eliminate gear-housing chatter in cars, trucks and SUVs equipped with limited-slip, posi-traction and locking differentials. Formulated for use with both synthetic and petroleum gear lubricants and safely replaces manufacturer-recommended friction modifiers.

I use Amsoil series 2000, I think it's 75w90 or 85w90, don't remember (but I believe it's the 75w90 Bob posted above). I need no friction modifer in my LS with that particular lubricant. It's been in there about 30,000 miles so far.

john i think the series 2000 lube is discontinued, i show it im my catalog, but its not in the online store and it wont allow me to order it through the part number. i think perhaps the severe gear is the same thing and it was simply marketed as something else, ill try to call AMSOIL tomorrow and see whats going on. did you know they stopped making the foam air filter for your trucks?

Yes, it's been replaced by the equal-to-or-better-than "Severe Gear" formulation. I'd still recommend it.

TS-120 discontinued? (I think that's the number). Any replacement on the horizon? I shouldn't need one, mine will be going strong for years to come. Maybe it just didn't sell. The cotton filter guys have the market locked up, and that's a shame since reticulated foam is superior in many ways.

TS-122 was the part number, i actually called the tech department and yelled at them. i dont know what they were thinking, that filter is used in pretty much all rangers and explorers 98 up, i hardly think they would have a hard time selling it. as of now its production is suspended indefinately

so the severe gear is the way to go? even for a lot of highway driving with 4.10 gears?

I think a full synthetic gear lubricant is the way to go in virtually all applications no matter what decent quality brand you buy.

Amsoil just happens to be my choice, even if (sniff) they discontinued my favorite air filter.

ha ha. billy, any of the gear lubes AMSOIL has to offer will work great for you!! you just have to choose which one youd prefer. the basic difference youre looking at is additive packages, thats what you are paying for. personally, im running severe gear in my F150 because i like to drive it hard, and id like all the protection i can get!!

so if i get the severe gear i dont need additive

most likely you will not need the additive, in the rare case that you do get chatter the slip lock is something you can always add in later

Old topic, I know.....
So for an FX4 with the Torsen limited -slip, what is your recomendation?

I will tell anyone interested NOT to put full synthetic AND friction modifier in an Auburn ECTED -- it maketh it to slip...

Nate, AMSOIL claims that its fuild will work without the modifier, I would try it without, and if you need it, you can always add it in

Can I run Severe Gear 75W90 in my dif? 1994 4L 4wd (more in sig) What will this do? Just keep wear down and stuff? Wouldn't hurt it to be replaced.

You sure can, it's great stuff. My combo limited slip/locker is a unique case. Other than that, I will still be running ALL Amsoil fluids in my truck.

PM sent

Ford specifies SAE 75W-140 synthetic axle lube for the Torsens. No friction modifier.

Torsens are FX4 only right? They came factory?

Factory rear Torsen L/S is standard equipment and available only on:

2002 FX4 Off-Road
2003+ FX4 Level II.

2003+ FX4 Off-Road have the Ford Traction-Lok L/S as standard equipment.

Traction-Lok is also optional on many other, but not all Ranger, powertrains.

When I recently installed the Detroit TruTrac in my '00; I used 75W/90 Redline synthetic gearlube. The nice thing about the helical gear torque sensing of the TruTrac is that it does not need any friction modifier additives...
The traction provided by the TruTrac is almost identical to what the Torsen provides.
Both tires provide power when the torque is applied. Very nice.....

OR 4x4