Rear Diff Oil Change?
 

Went to Jiffy Lube over the weekend for a regular oil change and they were trying to convince me that I needed to change the Rear Differential oil because it looked dirty. I declined to do it, but just want to make sure it's not really needed.

I only have 30K miles on my 2007 Expy. Has anyone had to do it so early?

P.S: They also wanted to flush my Power Steering fluid for $99.00.....

I wouldn't take my precious to those jiffy places. But since you were there, I wonder how they looked at your rear diff fluid without draining it out first. Maybe some optical system that they may or may not have?
I have 45k on mine and even the dealer didn't suggest such blasphemy. Check your user manual, but I believe you don't need to touch both until beyond 100k.

What's even worse, is that the guy brought the drain plug to me in the waiting room to show me how dirty the oil on it was. Not sure if a mechanic stuck his finger in the hole while the manager brought me the plug, or if that's just the same dirty drain plug they show everyone that comes in.

Word of advice. Don't ever ever ever ever take your car to Jiffy Lube. They will lie to your face to make a buck. They will charge you for services not performed. They will leave drain plugs off. They use wrong fluids that could damage your vehicle. Take it to any Ford dealer before you ever take it to any Jiffy Lube or any 'quick' lube place.

I think the recommended change time for the rear dif. fluid is 100K or 150K miles.

I would go under there pull the drain plug and see if the fluid is clean. I bet they didn't even change it. Check your oil filter also. They often don't change that as well.

Probrably one they show everyone. Anyway, dif. fluid looks dirty after a few thousand miles, it doesn't mean it has stopped working or lost it's properties. Just a way to get you to buy the service, or at least pay for it.

Watch these.

http://www.youtube.com/watch?v=wiCAJ8ULnaI

http://www.youtube.com/watch?v=Pf6KY6rrqYU

http://www.youtube.com/watch?v=MsLKNdebB6Q

And BTW, I do agree that power steering fluid should be changed at some point. It's not mentioned much or even in service manuals I don't think. But I would do it myself and it costs about $10 in fluid max!

Is there a specific specification for the rear axle lube for a 2007 Lincoln Navigator or can I use any 75W-140 synthetic axle oil? Also how can I find out what gear ratio I have and how can I find out if I have a limited slip axle which requires and additive?
Thanks,
Jacob

power steering fluid change
 

for about 6-7 bucks, you can buy a plastic pump that screws onto an oil bottle. Use the pump to pump out the power steering reservoir. Refill reservoir and start the engine. Turn the steering wheel stop to stop a few times. Turn of engine and pump out the PS reservoir again; refill reservoir. done
Pump can also be used to refill the differential when changing gear oil.

Anything on the required spec for the rear differential gear oil? Is there a specific ford specification that I should look for when I buy gear oil?

Check your owners manual before you go or ask the person at the counter. I believe the change interval for the rear axle is 100K miles. Again, check your owner's guide and maintenance guide for further details.

Ford uses a 70/75W-140 full synthetic oil with friction modifier for limited slip REAR axles. Some oils can be bought with the friction modifier all ready mixed in or you can by it separately and add to spec.

The filler cap on the rear axle is removed using a 3/8 socket extension. The standard Expedition rear diff. should hold nearly 3 quarts or 5.7....pints.

I was wrong, the rear differential fluid change interval is 150K miles as per the 2004 Expedition scheduled maintenance guide.

Where is the rear differential drain plug on a 2001 Lincoln Navigator?

It's in a different forum. This is 2007 and up.

I was thinking of changing mine out on my 97 Expy, but the owners manual says it has Synthetic gear oil and does not need changing for the life of the vehicle unless it is leaking or the vehicle will be submerged. Since yours is 10 years newer I cannot see how that would revert back to something else. Those places are such scams. I saw a report showing several of those stations charging for services they were not even performing. The guys would just sit under ground and spend a little time playing on their phones.