What Diff Do I Have???

[Schmo]

Anybody know how I can find out what diff I have on my van? Been searching on google with no luck.

2003 Ford E350 5.4L V8. Basic work style van, not the extended version.

[aw12345]

For a guess, a sterling axle

[Schmo]

From what I found, it looks like I might have a Dana 9.75inch (M60-IU). It does have Dana stamped on the cover but I'm not sure if that means anything. I also need to figure out whether or not I have a Dana Traction-Lok axle and whether or not I need to add the friction modifier.

[aw12345]

To find out if you have a limited slip diff, jack one rear wheel of the ground, put the trans in neutral and see if you can turn the rear wheel. Off course you do this with the engine off.

[Schmo]

So if you can turn the tire I assume that would mean you do not have a Limited Slip?

Is a Dana 9.75 inch different than a Dana 60?

[aw12345]

Does the housing look like this?




According to some manuals it should be a Dana 60U

Dana 60 has the 9 3/4 ring gear

[Schmo]

Does the housing look like this?




According to some manuals it should be a Dana 60U

Dana 60 has the 9 3/4 ring gear

Yes it looks like Pic #1 and the book does show Dana 9.75inch (M60-IU) as one of the options and it has Dana stamped on the cover, so that would make sense. I jacked up the driver rear wheel and I was able to get it to turn with the other wheel planted on the ground . . . I wouldn't say spin as it took a bit of pressure to turn the tire . . . that means I do NOT have LS right? I think something is up with my diff as I started to notice on the last couple trips that once I've been driving a while, I'm getting a noise and what seems like a bit of binding when I turn at very slow speed >5mph. Any ideas? I was hoping that if I had a LS, maybe the PO didn't put in the additive, but it doesn't seem like that is the issue . . . could it be as simple as the fluid needing to be changed or is that a long shot? Would it be best to rebuild what I have or swap it out . . . I need to keep the cost low.

[aw12345]

Well put some limited slip modifier in it and see if the binding goes away. There is a good change it has limited slip but the clutch plates are worn

[Schmo]

Well put some limited slip modifier in it and see if the binding goes away. There is a good change it has limited slip but the clutch plates are worn

Would the clutch plates being worn be why I was able to turn the wheel? Would adding modifier do anything if I don't have LS?

[aw12345]

Yup, is a possibility

[Schmo]

I figured I'd give some new fluid and modifier a try first and see if there were noticable issues first . . . the book calls for 3L of Hypoid SAE90 and 8oz of Friction Modifier. So I went to my local Kragen and called the local Pep Boys and they carry SAE80w-90 and other weights like 85-140 & 75-140, but not a straight SAE90. I would have thought the 80-90 would be fine, but the book has a different spec number for the SAE90 . . . M2C105 and the bottles of 80-90 mentioned it would meet M2C197 but nothing about the M2C105.

[mrchips]

I would think you have a 10.25/10.50 Sterling. Generally the axle you get in a Ford.

[Schmo]

I called Ford and the parts guy told me after looking it up in his book that the 80w-90 would be fine. I picked up some and made sure to get the one for limited slip just in case. Popped the cover . . . the fill hole plug was stuck on there pretty good and took some convincing with PB Blaster and a breaker bar, twisted one 3" extention in half before getting the fill hole plug out so I'm guessing it wasn't just recently that the fluid was replaced. Once I got the plug out and knew I could refill it I pulled the cover and in comparison to the plug, it came off easy. Everything looked pretty good . . . the teeth all look nice and I didn't find any chunks of steel in the bottom or any large shavings on the fill plug magnet. I have a screen on my funnel so I'll check to see if there's anything in the pan. So I'm thinking if something is wrong it would probably be a bushing going bad seeing that the other stuff looked okay, but am really hoping just changing the fluid will do the trick. Of course the diff cover got a good scrub down and a few coats of bright red!!!

[Schmo]

Got the diff all cleaned out, cover painted and reinstalled . . . giving the RTV a chance to cure and I'll fill it up with new fluid and see if that does the trick . . . fingers crossed. Checked the screen on my funnel and didn't find any metal chunks or shavings, which seems like a good sign. The fluid that came out was pretty dark and thick . . . almost the consistency of maple syrup.

So what are my chances that a fluid change will do the trick, and if the issue continues, what would you think the issue would be? Seeing that the gears look okay would you think that a bearing is bad . . . what else is there to go bad???

[Schmo]

I think the fluid change might have done the trick . . . got home from Cal City last night, did some tight turns on my street and didn't hear the noise or feel any binding . . . crossing my fingers, hoping that's all it needed.