Diff question

[Catsailor]

I have ID'ed my diff via the drivers door label - shows code 45 which is a Ford 4.10 according to the list that I found from a previous post. However, it does not give any other info so I can't figure out which Mag-Hytec cover I would be able to upgrade to. Also, mine does not seem to have any fill or drain plugs. How do you change the gear oil?

Thanks,
Tom

[xgatorx1976]

there should be a tag on one of the caver bolts. if not look on the front side drivers side there is a boss that will have a #70 in the center making it a dana 70 , otherwise its a ford 10.5 it should be a ford 10.5.
You could pretend you need parts for your diff call Napa and ask for a ring and pinion, they will have a few? that will pin piont which it is.

[Catsailor]

Any idea how to change the gear oil? I am towing a 44' gooseneck with 2 cars in it and I want to make diff oil change a regular maint. item.

[NumberDummy]

Originally Posted by Catsailor

I have ID'ed my diff via the drivers door label - shows code 45 which is a Ford 4.10 according to the list that I found from a previous post. However, it does not give any other info so I can't figure out which Mag-Hytec cover I would be able to upgrade to. Also, mine does not seem to have any fill or drain plugs. How do you change the gear oil?

Thanks,
Tom

45 = 1990/97 F350 / Sterling 10.25 / 4.10-1 / non Limited Slip / 7400 lb. Rear Axle Capacity

Info source: 1990/2002 Ford Light Truck Parts Catalog / Rear Axle Application Chart / Section 40 / Page 5.

(Parts catalog shows Sterling 10.50 used 1999/ on F250/350's)

[xgatorx1976]

pull the cover. replace the cover then fill with oil, i would use 85-140 gearlube or royal purple gearlube.

[Catsailor]

Tag says 4.10 10.2 and a few other numbers and letters. Also, I found what looks like a drain and fill bung on the front / drivers side - has a square indent for special tool perhaps. But it seems too high for a drain and too low for a fill.

[Catsailor]

Originally Posted by NumberDummy

45 = 1990/97 F350 / Sterling 10.25 / 4.10-1 / non Limited Slip / 7400 lb. Rear Axle Capacity

Info source: 1990/2002 Ford Light Truck Parts Catalog / Rear Axle Application Chart / Section 40 / Page 5.

(Parts catalog shows Sterling 10.50 used 1999/ on F250/350's)

Excellent, thanks for the info. According to an article in Diesel World Mag the Sterling 10.25 is a great axle. What do you all recommend for gear oil and upgraded diff cover?

[Catsailor]

Originally Posted by xgatorx1976

pull the cover. replace the cover then fill with oil, i would use 85-140 gearlube or royal purple gearlube.

So the little bung I found is really just a fill spot - and that is as high as the oil level goes?

[NumberDummy]

Originally Posted by Catsailor

What do you all recommend for gear oil and upgraded diff cover?

I'll let the FTE members that own one of these answer your questions.

I haven't progressed past the F150 yet!

[Dave Sponaugle]

That is the fill plug.
Fluid should be even with the bottom.

I use synthetic oil in mine 80 90 weight and add friction modifier if you have limited slip.

7.5 pints if I remember right.

A rachet and extension, 3/8" drive will get the plug out.

[Catsailor]

Thanks Dave. I got the plug out today no problem and the oil level was good, but the oil was pretty dark so its getting changed tomorrow. I tow a heavy load and want to make sure the diff stays happy.

[optikal illushun]

TRV for the gasket, i used mobil one 75-90 full syn when i change mine.

[Tom D]

Originally Posted by NumberDummy

45 = 1990/97 F350 / Sterling 10.25 / 4.10-1 / non Limited Slip / 7400 lb. Rear Axle Capacity

Info source: 1990/2002 Ford Light Truck Parts Catalog / Rear Axle Application Chart / Section 40 / Page 5.

(Parts catalog shows Sterling 10.50 used 1999/ on F250/350's)

Sorry to jump in on your post but could you tell me about my diff. The driver's door frame says C-5. Don't see any tag on diff. Thanks Tom

[Dave Sponaugle]

C5 code
4.10 ratio
6250 capacity
FORD Manufacturer
LIMITED SLIP type

Can be found here,
Ford Axle Code Chart .: Articles

[Tom D]

Originally Posted by Dave Sponaugle

C5 code
4.10 ratio
6250 capacity
FORD Manufacturer
LIMITED SLIP type

Can be found here,
Ford Axle Code Chart .: Articles

Thanks Dave