Oh btw, Honda is from Japan, and we all know how wacky those folks are!

 

Yes, still friends.. I cannot get mad at a fellow F450 owner! If you had a little F250 or F350 then maybe! JUST KIDDING GUYS! I love all super duties...

On a serious note, I still on a search to find out when ford actually wants this rear diff fluid changed. I still am coming up empty handed everywhere i look!

 

Perhaps this will help?

Drain
1. Drain when the lube is at normal operating temperature
(150°-200°F [66°-93°C]). It will run freely and
minimize the time necessary to fully drain the axle,
this insures the axle is flushed.
2. Remove the bottom two carrier to housing capscrews
and allow the lube to drain into a suitable
container.
Note: Dispose of all used lubricants properly by following disposal
methods approved for mineral- or synthetic-based
oils.
3. Inspect breather for clogging or corrosion. Clean or
replace as necessary.

Fill
1. Reinstall bottom two carrier to housing capscrews –
use Loctite 270 and torque to 142–158 lbs. ft. (193-
214 N•m).
2. Remove the filler hole plug from the side of the carrier
and fill the axle with the approved lubricant until
level with the bottom of the hole.
3. If wheel ends were removed, follow instructions in
the wheel end servicing section.
Always use the filler hole as the final reference. If lube is level
with the bottom of the hole, the axle is properly filled.
Note: Lube fill capacities are basic guidelines and will vary
based on the angle the axle is installed in a particular
chassis. Torque fill plug to 40–60 lbs. ft. (54–82 N•m).
TIP: The axle can be filled through the axle housing breather
hole. Fill until lube level is even with the bottom of filler hole in
side of carrier.

In a vocational setting Dana says to change the diff fluid every 60,000 miles.

 

S110 & S130 Series

 

Excellent information! best I have seen yet! thank you..

Few things I found interesting... From looking at the diff, if you unscrew the 2 bottom bolts it did not appear that would drain, it, but i suppose I am wrong.

Also, i cannot find anywhere the capacity of this diff so I know how much oil to get.

I also found it interesting they do not want any friction modifier or additive in there? even for the LSD?

 

Is it a truetrac in there like the service manual seems to indicate or is it a clutched unit?

 

It appers to be a truetrac.. After looking at the service manual, it states that the diff capacity is 6.6L and says it uses 75W-140. It does not state anywhere to use any friction modifiers or anything on this diff?

 

New to the F-450, as I have a (new to me 2009), and find this an interesting topic, and many questions have now been answered.
Would be helpful to know if the friction modifier is needed though, and I'll assume that 'synthetic' of the correct viscosity is used (6.6 L)?

Also, would the 'suck out' be better than the 'pulling two bolts' way of going about this job?
I'm betting there are alot of F-450 owners out there with more than 60K on their trucks that have no idea regarding changing diff oil!

Ford told me, in their opinion I had what they believed to be 'filings' in my rear diff., larger in size than what they thought was normal. Whether this is just 'fluff' or is in fact an issue to consider, my thinking is to change the fluid, so I at least can feel confident all is good. I've heard no odd noises, and the rear diff seems to be working just fine, but this is something I'll continue to watch.

 

Oh, i should have posted earlier, I did this and it was SO easy! The 2 bolts at the bottom are actually drain bolts, i had no idea the fluid would just come out of both. I jacked up each side of the axle (one at a time) and got out all fluid. I then out in Mobil 1 sytentic diff fluid. I called Dana and they said a friction modifier is not needed in this diff.

 

Haven't changed mine yet, as I'm just doing my research on doing this, so I wanted to thank you for your input, as it's been very helpful. Will be looking for 6.6L of synthetic 75w-140 fluid here real soon. So good to hear that those bolt holes do the job!

 

Just finished changing the S110 on my 08 F450 and the drain plug is the one at the 6 O' Clock position, the owners manual says 14 pints but after draining completely without pulling axels it took 5qts to refill thru the side fill plug (it's magnetic). I used teflon pipe thread sealant on the drain plug with no leakage after 1000 mi. and 4 wks time. I also used the teflon pipe sealant on the fill plug and just snugged it good, remember that is a pipe thread. I used Schaeffer's 75-140 Synthetic Gear Oil and the Schaeffer's Tech guy said no modifier needed that there is enough in it already but if chattering is experienced then add the Ford Modifier. I did figure 8s in the parking lot both left and right smooth as can be.

 

I said earlier there was no way to drain--around 140k miles, I was under the truck in the service bay while getting the fuel filters changed, and--guess what!--there in big letters on the lower housing are the letters DRAIN next to the bottom bolt. DUH!!
So it will be a lot easier next time.
I first had the chatter/shudder on takeoff early on--Ford said change diff fluid and add extra FM--did that and shudder was gone. I no longer have the use of the LS, guess clutches are worn out. Now at 181k and it is doing fine otherwise.
Joe

 

bump. doing a search for drain and refill for a 2010 f-450 DRW. no obvious drain or fill plugs. will check again tonight to see if the case bolts are in fact drain bolts.

 

Guarantee you there is a drain bolt--or two.

 

Bottom bolts in the pumpkin are the drain bolts.