Lifter583

I plan on changing the diff. oil to Royal Purple 75/140. I know I have to pop off the back diff. cover, anything else I should know? , such as the proper procedure ofre-sealing the cover?

Argonaut

I just did this a week ago.

Unbolt the rear diff cover. Make sure you have an oil catch below. Pry the cover off, be sure not to damage the mating surfaces. Oil will stink bad. There is no gasket per say, its gasket maker (make sure you have some hi-temp, oil proof gasket maker before you start). The panhard bar may block you from getting the cover all the way out. Mine didn't, with a little manuevering. Clean the cover and the differential well. You can get right into the diff to get any bits of metal and excess oil out. Once its all cleaned up put a bead of gasket maker on the differential. Carefully manuever the cover back into place, avoid touching the goop. Get the bolts ready, press the cover into place and immediately get some of the bolts in so it doesn't slip. Get all the bolts in and then torque them in an X pattern (sorry, forgot the torque spec...its not much though). At this point I let the car sit for 24 hrs, thats what the gasket maker I used called for to do a complete cure.

Next day: the fill plug is on the drivers side of the differential, slightly above where the pinion flange is,on the front (towards front of car). It takes a square bit to get it out, I think its a 10mm. I went looking at the autoparts store for a 10mm square bit and couldn't find one. The guy said just to use a 3/8 inch drive. Worked like a charm. The plug is magnetic and will probably have bits of metal stuck too it, clean it up. I purchased a little plastic hand pump at the autoparts store (like 5 bucks) and highly recommend it, makes getting the oil in much easier. Be really careful with the oil (and friction modifier if you are using it), the stuff smells and if you get it on your cloths you can write them off. Fill until it starts dribbling out (car level).

Good luck.

Hicompression

Subscribing.

Roy_R

That doesn't sound right, seems like you had metal fillings all over the place???

Lifter583

TY Very much! pretty much like doing my truck, but each thing has its own little quirks, I hate finding those out the hard way! I have 13k miles, hope I dont have metal shavings

Mikes_BLK_GT

Thats why I like the FRPP diff cover has both drain and fill plugs. Just pull and drain, insert then pull and fill, its that simple.

mAnYsTyLeS

Yes, I have the LPW girdle and it's the low-profile edition so if fits my aftermarket Panhard bar. Fluid changes should be easy now.

SCCAGT

Its right. The rear diff breaks in just like an engine, except it doesnt have the benefit of a filter. So, a magnetic plug is used. All the junk that comes out is like Etch-a-sketch crap. Lots ofvery fine metal pieces.
Everyone should do this before 10k miles on a rear drive vehicle. That same gear oil, with all those floaties, keeps the bearings lubed. All that metal is not good for the bearings.

Riptide

When does Ford recommend a change of differential fluid?

SCCAGT

Without looking it up, most manufacturers would recommend it be changed around 60k. But when you do it early on, you will be glad you did. Even at 5k, when I did mine, there was ALOT of crap that came out. Right under the ring gear, there is a small 'pit'. Larger pieces will settle into it. That magnet only holds so much.
Getting all the junk out early on, means less wear on the bearings because all those etch-a-sketch looking metal flakes circulate around the entire axle assembly without going through a filter.

And using an oil other Motorcraft will NOT void a warranty. There is a federal act (cant remember what it is right now. Someone else will chime in with it) that says it is ILLEGAL to enforce the use of a product to maintain your warranty, unless that product or service is provided at no charge. It would be Ford jpb to prove the oil caused the engine to fail. If it ever did come down to that, Amsoil has their own warranty to cover you in that event.