Differential binding at turn no fluid 1999 OHV

[slbeck1]

Okay, I heard and felt a nasty binding coming from the rear differential today. I was making a right turn from a dead stop and there was a "clack clack clack" binding noise and the vehicle felt as if it was stalling. This happened twice; both from dead going into a turn. I tried to re-create the noise in a parking lot, but it did not make the noise again. When I got home, i unscrewed the drain/filler plug on the differential...I stuck my finger into the hole and all I got was grey grease. I did not feel any fluid as far as i can reach into the hole.

Now, I have a 2WD 1999 sport with a 3.73 rear. My Hanes service manuel says the differential is "permenantly lubed, unless you cross creeks or boat launch. Well I have 118K mils on my Explorer, and i do have a boat, so it seems that I need to syringe the remainig fluid from the case and then refill up to the bottom of the plug hole...Question #1...WHAT TYPE OF FLUID DO I USE ON MY TRUCK? Question #2...IF A FLUID CHANGE DOES NOT SOLVE MY GRINDING/BINDING ISSUE, THEN WHAT ELSE COULD THIS BE; AXLE BEARINGS? IS IT TOUGH REMOVING AXLES ON MY TRUCK?

 

[BrooklynBay]

You might want to remove the differential cover to see what is inside instead of just pumping new fluid into it.

 

[slbeck1]

I'll do that. Do you know what gear oil I should use on the "Pernenantly lubricated" Ford rearend? This seems highly unusual. I'm wondering if there was ever any oil in there, or if it was only lubricated with some graphite lubing compound!? Any thoughts what I should use?

 

[IZwack]

Other thread deleted, please dont double post -- thanks!

 

[James909]

As for the lubricant needed my Haynes manual recommends 80W/90 gear oil for open diffs or synthetic 75W/140 with friction modifier for LS diffs. Many forum members including myself think that Ford's "lubricated for life" idea is ridiculous and that changing this fluid should still be done occasionally, especially with a LS. The "grey grease" that you saw is just the residue from the gear oil I believe. As for the binding, I would take the cover off and inspect everything and maybe post a picture.

 

[slbeck1]

I dropped the differential plate and there was fluid present, approx 2 liters. Everything looks good. No damage present and no signs of any metal in the gear oil.

I had the same stuttering sensation occur again this morning. I was moving into a turn and up a slight incline when the truck whined a medium-high pitch tune and stutterd...Maybe this is a transmission or other issue altogether!?