I checked the Eaton rear-end in my D-Max today and the oil level was a little low for the recommended levels in the owner's manual. It looks like this is a fairly common problem. Will it hurt anything to just dump the "grape juice" and fill it with Amsoil synthetic this early? I see no reason why it would since "grape juice" is synthetic, but I know I've read that the gears need to burnish during the break-in process. Any suggestions?

how many miles? If over 3k, dump it and fill it with your favorite brew

I'm at about 700 miles right now. So is this too soon?

You should change it after your first 500 miles of towing. I dumped mine at about 3000 miles with probably 1000 of that towing. It still looked pretty good but it was reassuring to get all of that metal out of there.

Well, I just added to it with the Genuine GM "Grape Juice" super-dooper wonder oil. Unfortunately, it was OVER A QUART LOW!





I'M PISSED TO SAY THE LEAST, but I guess I'm more concerned about the damage it may have caused. I haven't towed anything yet, but I just looked at the odometer and it went 750 miles this way. What should I do?

I wouldn't worry about it. They all are a quart low or more. I've yet to hear of a failure or any problems.


GM recently changed their specs and they no longer have to be full right up to the fill hole. I can't remember the exact specs. From what I understand they never changed anything in the diff so you should be safe filling it right to the top.

All right, I hope I haven't done any damage. When would I be OK to change it over to Amsoil or Mobil 1? At the recommended 5,000 miles?