Note: The same process applies to the 8.8 rearend, only you have to add a LS(limited slip) additive to your gear oil.

Precautions:
1. A jack/jackstands will help you a lot. I didn't have one on hand, but still managed to get this done.
2. WEAR A SHIRT YOU DON'T CARE ABOUT GETTING DIRTY! This is a messy process.


Materials:
1. A standard 3/8" drive ratchet.
2. 1/2" socket.
3. Brake cleaner.
4. Black RTV.
5. Flathead screwdriver.
6. 2 quarts of 80W-90 gear oil.
7. Oil pan.
8. Sanding block(optional).












Procedure:
Begin with placing your oil pan under your differential. Follow up by removing the fill hole plug with your 3/8" drive. If you have difficulty removing the plug, soak it with some PB blaster or WD40.


Next, you can start removing the bolts on your diff cover. Remove all of them completely EXCEPT the very top center one. Simply loosen this one.

The top bolt:


Once you have the bolts removed, take a rubber mallet with your flathead screwdriver and tap it between the differential and the cover.


Pry on it lightly (don't bend your diff cover!) until your gear oil starts draining.


Once the draining slows, you can remove the cover.


Your differential will continue to drip oil for the next couple hours, unbothered. If you don't have that kind of time, you can take your finger and scoop some oil out from the bottom.


Now, time to clean the inside of the cover!


YUCKY!

This is where your brake cleaner will come in handy. Take a rag and wipe any excess oil off of the inside of the cover. Then spray your brake cleaner on it and wipe any leftover oil off. Clean off any residual sealant with a razorblade, more brake cleaner, and a sanding block if necessary. The sanding block will also ensure there will be proper adhesion from the RTV.
All clean:


Do the same with the rim of the differential.


Next, you will put some RTV sealant on the rim of the diff cover. Apply it generously, going inside the bolt holes. Use your finger and make circular motions to spread the RTV around and rid any air bubbles.


Line up your bolt holes before placing your diff cover back on. You don't want to spread your RTV off the rim. Torque down the bolts in a "lugnut" pattern. Let your RTV harden, then fill up your differential and re-insert the fill plug. I almost used 2 complete quarts of oil. And you're set!

I coated the diff cover with gloss black spraypaint to make it look nice. Pics of it installed:

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1997 Ford Ranger 2.3L
It's lowered and stuff.
My Build Thread

great write up

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2002 Ranger Edge 2wd | 3.0 v6 auto 8.8 4.10 L/S | 32x11.50 Mud Kings | 28% tint | Chevy Shackles | Cranked B T-bars | Westin Bull bar w/ KC longrange| Three-tone airhorns | air box mod | k&n drop-in | foglamp mod | explorer ohc | alpine headunit | 10" mtx thunder 4500/custom box | kenwood amp| 4 wheel disk brakes | line of fire

Very cool how to!

you dont need to add limited slip additive to an 8.8 if theres no l/s.

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2001 XLT 4x4 V6 4.0L auto
SAS'd D44 and 8.8. dual lockers, 38s, 12 bolt h1's, some other odds and ends

Great write up! Is the RTV method you used the best way to keep the seal? On my jeep I use gaseket because the RTV just did work out well.

Thnx!

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2004 XLT 4x4 4.0 42K miles

Great write-up and pictures. For limited slip differentials you do not need to add friction modifiers with this.. http://www.royalpurple.com/gear-oil.html Ford Racing axle girdle (pt.#..M-4033-G1) provides a convenient drain plug and fill plug..as well as strengthening the rear-end...but is for the 8.8..not the smaller 7.5. It looks way better too.

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JBA s.s. headers&exhaust, K&N cold air intake, Bosch Iridium Plus 4 plugs, Royal Purple in motor, 5spd & diff.,Superchips programmer, axle girdle. Also have but yet to install KYB Gas-A-Just shocks and Belltech sway bars.

Great write up!

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2008 Ford Ranger Sport 4x4 4.0L
-5 speed, undercoating, tinted windows, keyless entry, 3.73 gears
-Pioneer AVIC-F700BT GPS w/10" Pioneer woofer
-3 inch Performance Accessories Body Lift
-33x12.5 r 15 BFG M/T KM2's

Question:

Anyone thought of using an oil extractor pump through the fill hole? I have one I have used for engine oil, pumping in gear oil, pumping in diff oil, draining gear oil, bleeding brakes, draining ATF, draining coolant and probably a few other things.

My only worry is that the old oil might be kind of thick. But, if it is easy, you can drain and flush as often as you like.

that would probably work, but by taking the cover off, you can inspect the guts of the differential to make sure its all good in there.
also this way, you know the seal between the cover and the diff is new and should last. you also don't know if you get all of it out unless you open it up.

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2002 Ranger FX4
4.0L SOHC, 5R55E Auto, 4.10 8.8 Torsen, 31x10.5/15 BFG ATs

AMSOIL is the best oil and the only oil you should put in your truck. Royal Purple, Lucas High Performance, and Mobil 1 just dont hold up to AMSOIL. AMSOIL shear stability will not drop ever. RP and LHP after 15 cycles will drop weight. That only 15 times it getting hot and cold, and its not the same oil it was when you put it in your truck. AMSOIL will never foam, witch means it will never make anything rust. Oh, and there oil filter are the best you can buy as well. With 98.70% filter efficiency. If anyone has any questions you can ask and i will try my best to answer. I dont know a whole lot about oil but i am learning more everyday. but i do know you want to use AMSOIL.

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2000 Ranger Sport. 5 Speed. Lowerd 3 in. i painted the grill and rims, 800 watt 10.

^Thank you for your opinion.
This thread is about changing the lube - not about what brand to use.

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2006 4.0 5 spd auto 4x4 Super Cab
BF Goodrich Commercial Traction T/A's
Royal Purple Throughout
Alpine Head Unit with some Infinity Noisy Stuff
NW Oregon

That is completely irrelevant. And it makes no sense on account of you not knowing how to type/form complete sentences.

__________________
1997 Ford Ranger 2.3L
It's lowered and stuff.
My Build Thread

On the oil extractor above. Did it, it worked great, both for pulling the old oil out (drained, let it sit, drained a little more, let it sit, done) and putting the new oil back in.

The pauses were because the pump was working kind of hard to extract. It did not get hot, I was just being cautious. I used it for both the transmission fluid and the rear end gear oil. I did heat the rear end oil in a sink of hot water first, that helped a great deal. Only issue is that if you get some air in the pick-up side, it will foam the oil a bit. You need to wait a bit (5 minutes) for the foam to settle to get a true full reading. Did the transmission and rear end in about 90 minutes. Did not get the benefit of inspecting the inner workings of the rear end, but frankly, all I could have done was point and say "wow, gears". I have no idea what I would have been looking at.

What came out of the transmission was pretty bad, what came out of the rear was freaking nasty. I will likely be changing that one again just to be sure. Seems it had never been changed before.

I was afraid of this. The Getrag rear in my CTS-V has a drain plug. It was so easy to change. I know the Ford 9" has a great reputation for being the best ever created. I hope that technology has trickled into the truck I have now. I do like the fact that you can open it up and see the gears to check for damage.

Previously, I would change the rear fluid in the car every 10000 miles. I think that may be extreme in the Ranger. What is a suggested mileage interval to change?

Also, I've tried a wide variety of fluids in the rear of the car. Before going on a road trip to SC, I changed the engine oil and rear fluid (Royal Purple). By the time I got down there, it had broken down and was making grinding noises. I am not an AMSOIL dealer, but I will be changing to their products immediately.

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Rides:

2011 XLT Ranger 4x4 Super cab auto: stock*

2005 CTS-V: KW coilovers, Hotchkis sway bars, Kars stage III traction bar, UUC short shifter, cags eliminator skip shift, UUC stainless brake lines, BMR toe rods and tie bars, custom GTO fuel rail covers, AMSoil fluids

whats better the RTV or to just buy a new gasket
im thinkin bout doin the rear Diff fluid change since im sure it is way overdue. also i dont know if i have a limited slip Diff if someone could tell me if i do or not
the specs on my ranger are
1989 ranger xlt
2.9L V6 engine
5 speed manual trans
RWD not 4x4