Diff Fill??

[Crazy Horse]

Does anyone have any insite on why the Dodge service manual recommendes filling to 1/2 or 3/4's of an inch below the fill hole? Has anyone filled to the opening the way you used to in the old days? I'm wondering about leaky seals if I top it off.

 

[LSMITH]

Fill it to the bottom of the filler hole and jack one side up as far as you can. Let it down and refill. Jack up the other side and let it down, refill again right up to the bottom of the filler hole. You are now full of lube. If you do not get some oil in the axle tubes you will run the seals dry and burn them up, hopefully the wheel bearings will not get trashed too. If by some chance you got too much oil in it the diffs are vented, the excess oil will puke out the vent. Put all the oil in it you can, you are better off in the end.

 

[John Berger]

I've got a Mag-Hytec and I've got 7. 5 quarts of Amsoil lube in it. I've never had any of it puked out the vent tube. I did have a leaky pinion seal problem, but that ended up being the axle housing, which was replaced under warranty. No leaks since. I agree with the last post. Get as much lube in it as you can, especially if you tow. It is always good for a cooler rear-end to prevail