What lube to use?

[pyro2nite]

I was checking under the truck this morning, and discovered that the pinion seal was leaking. I checked the fluid level and it needs to be topped off. The Ford parts are closed until Tuesday, because of Labor Day and I need to drive back home Monday. I will need to buy after market lube at Kragen or O’relliey and want to know what to look for. It is a limited slip diff so I can’t just put the old 90wt in it. I sometimes don't trust the person behind the counter giving the right info. Thanks

[SuperCrutyPS]

I found this:
Ford Power Stroke Diesel 6.4L Product Recommendations

Scroll down a bit - It says Ford uses a 75W-140 oil in their diffs. Hope it helps ya get home!

[cartmanea]

Check the vent to see if it is plugged, that can cause the pinion to burp fluid. It is the hose from the top of the differential to the frame rail. To check, pull it down and blow in the end and see if it takes air.

[08pwrstrokr6.4]

umm its in the back of the manual.in the specs part.

[Jarrod B]

Originally Posted by SuperCrutyPS

I found this:
Ford Power Stroke Diesel 6.4L Product Recommendations

Scroll down a bit - It says Ford uses a 75W-140 oil in their diffs. Hope it helps ya get home!

75w140 SYNT!

[gary2070]

Ford has issues with that seal I have already had to replace my '06 seal.

[pyro2nite]

OK, first off shame on me I did not have the owners manual. Hmmmm. Picked up some 85-140 syn blend. Put 28oz to fill. Checked the vent tube and it was OK. The hard part about this is, it is about 4000 mile out of warranty and it looks like it was leaking before that. Had a 89 Bronco, 98 Ranger and they both leaked from the pinion seal. Should have checked it more often. Thanks all for the replies.