Differential leak, naive owner.

bkvanbek · #1 (**permalink**) 06-29-2009, 08:51 PM

I changed differential oil this winter, no leaks afterwords, but now there is oil all over and a couple drops on the driveway from overnight. I think it is the seal from the drive-shaft, maybe the cover too.

And How do I replace the seal, and how do I figure out what axle I have?

joe blow · #2 (**permalink**) 06-29-2009, 09:51 PM

IF YOU HAVE AN F250/F350.......I am certain you have the Sterling differential.

How much fluid did you put back in? If you overfilled it, that is as bad as running it with not enough differential fluid.

The front seal and the differential cover leaking AFTER you did the fluid sounds like too much fluid......if not...

The diff pan is not sealed correctly....remove and MAKE SURE it is straight (sealing surface)

The pinion seal is a little more difficult....no disrespect intended, but according to your post header "naive owner" it might be a little more challenging since it needs to be retorqued once the seal is replaced. You'll need a torque wrench.

bkvanbek · #3 (**permalink**) 06-29-2009, 09:55 PM

It was six months ago I changed the oil and I am sure I did not overfill it, you fill it until it comes out the fill hole, right?

I do have a torque wrench, up to 150#, air wrenches and big sockets. What does it take to change it?

jboczar · #4 (**permalink**) 06-29-2009, 11:13 PM

Remove drive shaft, remove rear calipers to eliminate drag, installed torque wrench onto pinion nut inside flange, record torque required to turn nut. remove nut and use a 3 or 2 jaw puller to remove pinion flange, use a flat head screwdriver and hammer to remove seal. Find a suitable device to fit over new seal and using a hammer drive it in, Ford has a special tool but anything like a large socket that fits well over seal will work. reinstall pinion flange and use nut to draw it in. Use torque wrench to check turning force, it should be 5 inch pounds more than original turning force.

bkvanbek · #5 (**permalink**) 06-30-2009, 06:45 AM

Thanks for the help.

cartmanea · #6 (**permalink**) 06-30-2009, 02:02 PM

Before you do anything, check the vent hose. If the vent is blocked, high temps will make it burp oil out the pinion seal. There is a hose that comes off the top of the differential and goes to the frame rail, make sure the end of it is clear and you can blow air through it (with your mouth, not an air compressor). Here in Oregon they get plugged up with leaf-cutter bees a lot.

Radical · #7 (**permalink**) 06-30-2009, 08:48 PM

Funny you mention the leaf cutter bee's plugging the breather, I just finished evicting 3 bee larva (think they were mason bee's here on the coast) out of my breather as it was starting to burp fluid on my driveway. Another problem solved

pjwoolw · #8 (**permalink**) 07-01-2009, 12:52 AM

I use a small fuel filter instead of the vacuum tee from the factory.

bkvanbek · #9 (**permalink**) 07-01-2009, 06:17 PM

I checked mine, it was clear, but I think the cover must leak too.

bkvanbek · #10 (**permalink**) 07-03-2009, 08:40 AM

I loathe putting the oil back in the differential, there must be a better way.

joe blow · #11 (**permalink**) 07-03-2009, 08:47 AM

Why do you loathe doing this? Most if not all differential fluid containers come with a spouted plastic end....I don't think it is that messy....certainly not difficult.

bkvanbek · #12 (**permalink**) 07-03-2009, 09:10 AM

I don't find it easy at all. It takes many minutes to get a quart in the differential, spilling some. A friend of mine helped with the seal, he complained about putting the oil in too.

Radical · #13 (**permalink**) 07-03-2009, 03:11 PM

A funnel can help if you can fit it in.

cartmanea · #14 (**permalink**) 07-03-2009, 04:35 PM

Just be sure and have the oil warm, 80-90 degrees and its a lot easier. I filled mine when it was under 40 degrees in our shop and it took a while to squeeze that cold thick fluid out the nozzle.