[me1magoo]

Have you? I mean if you have and THEY told you directly to use 75W-140, that is a significant bit of information to be considered. Will they/ Have they put that in writing?

 

[MikeyB]

I haven't called them, other's have and got the 75w-140 for hot weather towing answered. BTW, the Duramax crowd gets the same answer too.
But anyway, go ahead and run 75w-90, you'll be fine.

MikeyB

 

[wreedCTD]

Here is a cut and paste of the manual. Personally I would use the Mopar fluid only and for sure the 75w 90 as this is the required weight of oil.



FRONT AXLE ± .03 L (1 oz)
C205F 1.6 L (56 oz.)
9 1/4 AA 2.2 L (76 oz.)
9 1/4 AA EL 2.2 L (76 oz.)
REAR AXLE ± .03 L (1 oz)
9 1/4 2.1 L (72 oz.)***
10 1/2 AA 2.5 L (85 oz.)
10 1/2 AA EL 2.5 L (85 oz.)
11 1/2 AA 3.6 L (122 oz.)
248RBI (DANA 60) 2.8 L (46 oz.)****


AXLE
NOTE: DaimlerChrysler recommends using Mopar® lubricants or lubricants of equal quality.

FRONT AXLE
C205F - Mopar® Gear Lubricant 75W-90
9 1/4 AA - Mopar® Synthetic Gear Lubricant 75W-90
9 1/4 AA EL- Mopar® Synthetic Gear Lubricant 75W-90
REAR AXLE
9 1/4 - Mopar® Synthetic Gear Lubricant 75W-140
10 1/2 AA - Mopar® Synthetic Gear Lubricant 75W-90
10 1/2 AA EL- Mopar® Synthetic Gear Lubricant 75W-90
11 1/2 AA - Mopar® Synthetic Gear Lubricant 75W-90
248RBI - Mopar® Gear & Axle Lubricant SAE 90
NOTE: Trac-Lok® differentials require Limited Slip Additive in the lubricant. Trac-Rite™ / Trac-Rite EL™ differentials DO NOT require Limited Slip Additive.

What manual did you get this from? My 06 manual says 4.0L or 135 oz. for the rear diff.

 

[501Cummings]

I ran a remote temp sensor on my rig once for ghits and siggles 11.5 rear 4:10 posi towing 27 foot fifth wheel (8000+ lbs) the hottest it got was 165 up hill. Now I can't say if how accurate it was as it was not IN the diff but on the outside lower housing and was covered on the out side (not the side touching the diff-cover) with Styrofoam and then duct tape. I know it was Mickey Mouse but was only for fun and lost the sensor about 400 miles into the trip when I hit some rain LOL!!

 

[me1magoo]

I filled them with 75W-90. I added exactly 122 ounces to the rear and 76 ounces to the front and they were exactly in the same spot as when I checked the level before draining. The fluid that came out was perfectly clear, but both front and rear and some very fine gray "material" on the plug and like a film on the cover and inside. I assume that is just some fine wear material. No chucks or pieces of anything and nothing that I could see or feel on any of the gears, just smooth and clean. The rear was tougher to get cleaned out, it kind of sinks down inside where the front tilts outward toward the cover. I just put the reusable seal back on and tightened up the bolts several times and so far so good, no leak.

 

[six pack]

What manual did you get this from? My 06 manual says 4.0L or 135 oz. for the rear diff.

Here is the copy and paste from the 06 manual.
9 1/4 2.1 L (72 oz.) ***
10 1/2 AA 2.5 L (85 oz.)
10 1/2 AA EL 2.5 L (85 oz.)
11 1/2 AA Open 4.2 L (142 oz.)
11 1/2 AA Trac-Rite 4.0 L (135 oz.)
248RBI (DANA 60) 2.8 L (46 oz.) ****
*** With Trac-Lok add 118 ml (4 oz.) of Limited Slip Additive.
**** Add 147 ml (5 oz.) of Limited Slip Additive
** Includes 0.9L (1.0 qts.) for coolant reservoir.
*Nominal refill capacities are shown. A variation may be observed from vehicle to vehicle due to manufacturing tolerance and refill procedure.

 

[wreedCTD]

What manual was your original post with capacities from? Why did they change it in 06? Also are these capacties somewhere in the owners manual?

 

[wreedCTD]

Just checked the manual on the duramax and they recommend 75w-90 also.

 

[six pack]

What manual was your original post with capacities from? Why did they change it in 06? Also are these capacties somewhere in the owners manual?

05 was the original cut and paste.

I see they just added the Trak Lok as taking less, most likely as there is less room for fluid with that carrier vs the open one.

 

[wreedCTD]

the first year of the trak lok was 06 or just the revision to fluid capacities in 06?

 

[six pack]

the first year of the trak lok was 06 or just the revision to fluid capacities in 06?

Not the first year, I think they just missed it previously.

 

[rdnckplmbr261]

use the 75w140, you cant go wrong. but you can if you something else and tow heavily.