Serviced the differential on my "new" F-150

[luvmy40]

I recently picked up a "new" '07 F-150 to replace my old '96 Ranger. I bought it the day it hit the lot so it had not been gone over at all by the dealership. I changed the oil and filters the day I got it but didn't get to the differential till today.

 

The diff. cover was more rust than metal and it looked like it had been seeping fluid for a long time. I got a new cover and gasket and researched the preferred diff. fluid. The consensus seems to be Royale Purple 75w-140. That stuff is pricey! 2.75 qts. @ $21.00/qt

 

When I popped the cover I got about a quart of mud to drain out and had to dig the sludge out of the case with paper towels. The gears look good and it had not been chattering or slipping so I think I'm good to go.

 

I don't think I'll do it again without a lift though, that was a PITA!

[Sylvester]

Good for you, I assume it does not have limited slip differential. You road in my 96 at MD, and I am very particular of maintaining the service. Glad you are the same.

 

[luvmy40]

Yes, it is a limited slip diff. That's why I went with the Royale Purple as it has the LS additives already. The other options in my area, Valvoline and Mobile One synthetics need the LS additive.

[BlueSky]

The additive is only about $6 I think, less than $10 for sure. I put valvoline 75/140 in my 9.75" rear diff without the additive because it says on the bottle it is to be used with traction lock or something to that. The traction lock was trying to lock up a little too soon but it didn't make any noise so I didn't go back an add the viscosity additive. Mine now has 152k miles on it.

 

What engine does your truck have? If it is the 5.4, change the oil often. they are infamous for VCT problems.

[luvmy40]

It has the 4.2l, V6.

 

The only criteria for choosing a truck was that it had to have an 8' bed and not have a Triton V8.

[BlueSky]

It has the 4.2l, V6.

 

The only criteria for choosing a truck was that it had to have an 8' bed and not have a Triton V8.

 

I remember now. The 4.2 is an excellent engine after the 97 and 98 editions.

[luvmy40]

The MPG isn't great but that wasn't a high priority. The Ranger was only getting 13-15 mpg. The F-150 is hitting 15-18 mpg and has almost double the cargo and weight capacity.

 

Keep in mind, this is not a primary use vehicle. It's a secondary winter transport(tertiary summer transport) and an emergency recovery device. I.E., a vehicle of convenience.

[Sylvester]

I didn't know that RP included the LS modifier. sorry. I have been buying the lube plus modifier. Remember way back when...you bought for LS or without, no secondary product involved.

 

Just showing my age.

[uhfradarwill]

Lifts are for sissy's that don't like the taste of used vehicle lubricants!!

Just sayin

[luvmy40]

I don't mind the taste. I just don't like wallowing in the puddle that missed the drain pan. I still smell like burnt gear oil after 4 showers!

[luvmy40]

Now that the differential is full, the leaking pinion seal made it's self known!

 

As usual, the job required two extra trips to the parts store(my home away from home) since I grabbed the wrong seal the first time and none of my pullers were up to the job.

 

So, 4 hours later the 1/2 hour job is done.

 

:banana::banana::banana:

[Flyinfool]

If there was as much sludge as you said, I would plan a second fluid change after a couple of hundred miles.

If the new cover does not have one, epoxy in a rare earth magnet to grab small iron particulates. I add the magnets to my trans at the first oil change also, and I have a magnetic drain plug for all of my engines. But then I tend to drive a vehicle till the wheels fall off.

[luvmy40]

The new diff. cover does have a magnet and the OEM fill plug does as well.

 

I also spent a good amount of effort cleaning the sludge from the diff. case.

[BlueSky]

What procedure did you use to retorque the pinion nut?

[luvmy40]

I measured the exposed threads with a vernier caliper and torqued it back to the same location, which turned out to be the mechanical limit.

[BlueSky]

I've read that marking the nut position to the pinion housing was a good way to retorque. I haven't had the pleasure yet on my 02 F150.