I read an article the other day about a common, but widely unknown, manufacturer requirement to change the diff oil at 3,000 miles. The reason for that is because the diff doesn't have a filter like the engine does. They went on to say that the most damage is done to the diff in the first 5,000 miles with the wear metals from manufacturing, etc, imbedding themsleves in the gears. I've never done it, but I do see what they're saying. Anyone else heard of this? Anyone routinely change their diff fluid at an earlier age for this reason?

 

NEVER would be a waste of $ stick with ford service requirements so guy from jiffy lube must of started that rumor

 

Why not change the brake fluid, transmission fluid, coolant fluid and power steering fluid while you are at it. O and don't forget the windshield washer fluid too . You should also deflate your tires and reinflate them with new air from a top off the line air compressor for best quality air. I mean really, I think that's a little over the top.

Sorry, just had too. I guess it wouldn't hurt but would be a waist of time and money.

 

So, what did you read this information in?

The plug in your differential has a magnet to capture all of those nastly little peices of ferrous particles, chips, etc. There's only a limited amount of non-ferrous (not magnetic) materials in a differential/alxe housing. So the risk of damage is very low.

It surely wont hurt anything to change the diff oil early. But it's a total waste of money.

 

Along the same lines, my Ford dealer was trying to push a power steering fluid flush on me at 15k miles. He said that it was vital to the system to be flushed that soon. I asked to see my fluid, and to compare it to some new, out of the bottle. That stopped him in his tracks.

 

I had to change the diff fluid at 3K kms in the LSD of my AMG Mercedes. It isn't that far fetched.

It was $220 to do it. It is probably cheaper with Ford.

 

Ford recommends that you do not do any heavy towing for the first 5,000 miles after any kind of differential rebuilds or repairs....im sure the same principle might also be in theory applied to a brand new vehicle.

 

My owner's manual says 1000 miles on a new vehicle. Which Ford manual are you looking at?

 

The owners manual on page 401 says the Rear (8.8/9.75 inch) axle fluid capacity is 5.5 pints (2.6L) and calls out 75W-140 Rear Synthetic axle lubricant.

The note referenced to this section says "3 Service refill capacity is determined by filling the axle to 1/4-9/16 inch (6-14 mm) below the bottom of the filler hole with the vehicle on a level surface. Add 4 oz. (118 ml) of Additive Friction Modifier XL-3 or equivalent meeting Ford specification EST-M2C118-A, for complete fill of 8.8 inch and 9.75 inch Traction-Lok axles."

I may just change mine out for the heck of it since it should be an easy process.

 

I figured this would cause a big flare up, but it actually got me thinking so I thought I'd post it anyhow. I never put any thought into it before. I read it in some magazine at my in-laws' over the weekend. Not sure which one; I just needed something to occupy my mind while I was administering a bottle to our youngest.

 

Yea, I read the same thing after I bought my 2001 screw back in 2000. Can't remember where I read it, probably flippin through owners manual and other little booklets that come with a new truck packet. But anyway, I went and had it done at the dealer between 5-10k mi. Can't remember if it was on warranty or not. Good idea I think, newly mfr. gears meshing together at that much torque will weed out the weakies.

 

Where oh where has common sense gone . . .like reading something and knowing it is BS?

 

At my second oil change the lube shop tried to tell me my rear oil needed to be changed, they had some color charts and a sample of my rear oil. They wanted to charge like $90 to do it and I said screw that I'll have ford do it for free if it needs changing at 9k. Anyways, when I went to ford they said they have had several people coming in and saying they've had the same thing told to them at the same lube place. Ford didn't even look at it. Makes me wonder now haha.

 

I have serviced many diffs as a mechanic. The only time they have ever needed it were posi's abused by kids which burned the fluid into bacon grease. Then over loaded towing hauling which took the bearings out or galled the gears. I only change my own diffs every 100-150k for grins. The fluid has always been clean and in good shape.

 

Ford plainly says that the diffs are filled for life and changes are never required except if you get contaminants (like water) in them or you are opening them up for repairs. However, I think it's a good idea to do it every 100k, especially if it's a limited slip.