Just finished off 1st oil change @ 33,000. As expected, it was black w/ gray
goop on bottom. No metal or shavings at all. Raked out all I could on bottom w/ my fingertips. Cleaned cover & gasket real good w/ diesel & also cleaned
housing where gasket rests. Re-installed cover;snugged bolts w/socket(no need for torque wrench & all that, the gasket compresses very well & you can feel it sealing) & filled w/ Valvoline 75-90 Syn. Took a bread sack tie &
measured where I was at (You can see where you're at w/ a bread tie better than a paper clip) thru the fill hole, stopped @ 1/2, 1/4 ",somewhere thereabouts; put plug back in hole; NOTHING TO IT!

It really p***es me off how DC gets to people who take thier truck to the dealership to have thier service done. I spent about $23 on the oil to do this.
I read a recent post where the dealerships get $125 PER AXLE for this! I have saved enough on periodical maint. to pay for my quad box!

The only thing I've had the dealer do is flush the tranny. DC recommends on severe schedule to do pumpkins @ 15,000. I haven't seen some of the guys who haul 25-30 calves in a '36 gooseneck; maybe they need it. I pull a 5,000
'29 TT about 6 times/yr. & I GUARANTEE ONE THING. I AIN"T DOIN THE DIFFS
ANY MORE FOR AT LEAST ANOTHER 30,000. DC wants to bleed all of us DDDRRRYYY! I think Ford or GM needs to work out something w/Catepillar, say a 7.0 liter 400 hp sweetie pie. DC needs some competition so we could spread the money around a little

 

Koogla, do you remember how much the front and rear diffs held EACH? I know 7 qrts will do but I am gonna use 75/90 in the front and 75/140 in the rear so I may need to get a little more of one or the other.

 

Be careful! I started out changing diff fluid 7 years ago, then it was a brake job, new exhaust, air filter, tires, shocks. Before you know it you got 200K miles on your truck and it runs as good as the day you bought it.

 

Have not done front yet,will catch it next weekend. The rear took about 3 1/4
3 1/3 qts. so you'll need 4. Dunno what size the ring gear is. I guess maybe a 4.10 is a diff. size ring gear or something. Mine is 3.73. From what i've read on here, diff size gears take diff amts. of oil or something. In any case stop it
1/2, 1/4" shy of the hole. My cover has a fluid level marker on it.

 

front uses less than 3 quarts. did front and rear on the same day. started out with 7 quarts, ended up with 1/2 quart. I don't have a fill line, so I filled it up to the drain hole.

 

There is no difference in capacity between different gear ratios, but when you use a physically larger diameter ring gear, you get a larger case, which holds more fluid. For example, a Dana 60 holds less fluid than a Dana 70, which holds less fluid than a Dana 80. The AAM 11.5" is the biggest ring and pinion I have ever seen in a pickup truck, and takes a lot to fill it. For comparison, a GM 12 bolt or Ford 9" take about 2 quarts.

 

Gotcha!

 

My dealer wanted $139 an axel. They get you either way $21 for the mopar oil.

 

What does it hurt if you fill the differentials to the bottom of the plug opening?

 

Doesn't hurt anything. I've read on this site that some of these diff covers have a fill line. Mine doesn't. My Dad taught me that if you could stick your pinky finger in the hole and feel fluid, it was at an acceptable level.

 

With my f-550 2 years ago, the rear axle was a dana s135 (or something close) it was setup just like a 9" so I never touched the fluid but it was huge. it even had square axle tubes.

 

They wont get me for $21 a quart..thats crazy!!

 

Ditto.

Depends on the size of your (...er your truck's) rear end though.

Accordging to the manual, the 11.5" takes 3.62 liters, the 10.5" 2.25 liters. I think some 2500 have the 10.5" if I'm not mistaken. The front 9.5" takes 2.25 liters, but mine took closer to 3 for some reason (about 1/8" from the bottom of the hole). P.S.

Get a .pdf of the manual! They're free!

 

Well they're gonna get me for that much $$$. I'm taking mine in next week because I really don't want to do it. maybe next time. I do my own oil tho..

 

This is easier than a oil chg. to me. Takes a little longer to undo all the bolts.