2nd Gen Non-Engine/Transmission lube capacity with Mag-HyTec rear diff cover on 2500

[TomGolden]

Howdy all,



I recently went from my old MagView rear diff cover to a Mag-HyTec cover. I remember from a couple years ago when I was getting the MagView that the 2500 4x4 trucks with the manual trannies use a Dana 70/80 hybrid, and so use the Dana 80 diff cover, which is what I ordered from Geno's Garage, and it fits perfectly.



According to the installation instructions, the Dana 80 differential will hold 8 quarts with the Mag-HyTec cover. I drained about 5 quarts out of my diff when I changed covers last weekend. I put 7 quarts new gear lube back in with the Mag-HyTec cover, and the dipstick was right at plumb full.



I know that in things like the engine, if you put too much oil in it, you can cause damage to seals and other things, and figured the axles would have the same issue if overfilled.



So, on my truck, with the Dana 70/80 hybrid axle, should I go to 8 full quarts, or go by the dipstick in the Mag-HyTec?



Thanks all,

Tom

 

[willyslover]

do some reasonably fast fig 8's then let sit on level ground for a while to drain into the pumkin to natural level then re-test. . remember the housings carry fluid to the bearings also so don't short it

 

[Diesel Gunner]

Tom,



If you look at where the full mark is in relation to your axle housings and axles you will see that the lube level will be at about the bottom of the axle shafts. At least it is on my Dana 80. Filling the rear end any fuller cuould produce negative effects. Like lubricant foaming (which is always bad), building of pressure in the rear end (not likely unless the vent is plugged) and causing seal failure, or high temperatures caused by foaming and/or low lubricant level.



When I installed my Mag-Hytec front diff cover, I filled it to the full mark on the dipstick and it expelled a small amount of lube from the vent line. Obviously, since it has stopped and the diff is not low or dry, it was slightly overfilled and adjusted itself.



Also, there is a small allen drive plug in the data plate in the middle of the cover. I believe that this would be the level for a factory fill. You can remove the plug and when lube stops flowing you would be at the "1/2" below filler level". My rear diff is filled to the full mark on the dipstick, has seen temps in the 200 degree range and has never puked any lube from the vent.



To sum it all up, the full make on the dipstick should be about even with the bottom of the axle shafts. The plug in the data plate area should approxiamate a factory fill level. And willyslover is also correct.

 

[Rman]

On my MagHytec it has two marks on the dipstick. I have mine just a hair under the top mark. Like Gunner said this puts the oil under the axle shafts. Being level is important, because of the angle the dipstick goes in there. The figure eight thing is pretty important, but just to let you know when i filled mine i could only get about 7 and a 1/4 quarts in. 90w oil is pretty thick and i didn't have the time to let it drain out for a day. I'm sure the axle housings and the gears held up the rest of my oil, probably the case with yours as well.



Oh yeah check it often too, the mag hytec dipstick is magnetized. I frequently pull tiny shavings out of mine, just normal wear of the gears. Pretty nifty to be able to pull them out without draining the oil (my truck also only has about 22k on it, i changed the cover at around 5k) That could explain the wear. Yours will probably show less, but still better safe then sorry.