So I finally got around to changing the rear diff on my truck. I read a few things about the 2011's changing rear axle manufacture, from AAM to ZF. I heard there were a few recalls on this axle, initially due to the fill port being to low (apparently the factory was then overfilling to compensate), second the cover being an odd shape and causing oiling issues, etc. Mine was built January of 2011 so it apparently has the fill hole in the correct location and the dealer says the only thing done to mine was a restriction plug installed to keep oil on the pinion.
So I was gearing up for a fight to remove the fill/drain plugs. They require a 14mm hex, not 9/16 or anything else. I used a snipe but they released without any drama. That was a first. Ever. On level ground I opened the fill port and approx. 400ml of oil came out. I figured [censored] as the oil was marginally warmer than ambient, so maybe 10 to 15C. I dont think the thermal expansion of the gear oil at that temp would be that much. Was it factory overfilled? Who the [censored] knows. I filled her up and then topped it off with 400ml from the vent tube. I will burn some miles on her and if there is no growling or the truck doesnt catapult off the driveshaft it will be a success.
The transfer case was uneventful and is full of Amsoil now. Next up is the front diff when I got time.
Anyone else have experience with the early model ZF 9 1/4 axles?
So I was gearing up for a fight to remove the fill/drain plugs. They require a 14mm hex, not 9/16 or anything else. I used a snipe but they released without any drama. That was a first. Ever. On level ground I opened the fill port and approx. 400ml of oil came out. I figured [censored] as the oil was marginally warmer than ambient, so maybe 10 to 15C. I dont think the thermal expansion of the gear oil at that temp would be that much. Was it factory overfilled? Who the [censored] knows. I filled her up and then topped it off with 400ml from the vent tube. I will burn some miles on her and if there is no growling or the truck doesnt catapult off the driveshaft it will be a success.
The transfer case was uneventful and is full of Amsoil now. Next up is the front diff when I got time.
Anyone else have experience with the early model ZF 9 1/4 axles?