This weekend I spent some time crawling under Senior to see how much damage I had caused by driving back from Moab in front wheel drive. On the way back Jeff and I had discovered gear oil sprayed under the passenger side of the truck. It seemed to center under the transfer case and back. So, we thought that I had blown a seal in the case. However, during my visual inspection of the undercarrage, I realized that this was an A340H with an integral transfer case! (Silly me, when my A340F transmission went out a couple of years ago, it was replaced with an A340H.) The transfer case ATF fluid looked decent (and so does the transmission). So, where did the gear oil come from? 
It came from the front differential. I think the fluid got very hot and sprayed out of the vent. (The vent was clear, which is odd.) The 'slipstream' under the truck caused the oil to hit the transfer case and gas tank, all on the passenger side of the vehicle. I drained the front diff and the gear oil looked black and bubbly. It looked like it also had forced it's way through the axle seal on the driver's side. I also found what appears to be chips from my gears. Of course, for all I know these could be very old. Can anyone tell if I should be overly concerned about this damage from the picture I've attached?
It's a pity that there is no inspection hatch.
So, it looks (fingers crossed) like all I need to do is re-install the drive shaft and repack my bearings and everything should be ok for the summer. Although, my hopes of putting a Marlin on my transmission are out. Of course, I could use the gear bits as an excuse the replace the gears.
Should I check anything else?
Matt
It came from the front differential. I think the fluid got very hot and sprayed out of the vent. (The vent was clear, which is odd.) The 'slipstream' under the truck caused the oil to hit the transfer case and gas tank, all on the passenger side of the vehicle. I drained the front diff and the gear oil looked black and bubbly. It looked like it also had forced it's way through the axle seal on the driver's side. I also found what appears to be chips from my gears. Of course, for all I know these could be very old. Can anyone tell if I should be overly concerned about this damage from the picture I've attached?
It's a pity that there is no inspection hatch.So, it looks (fingers crossed) like all I need to do is re-install the drive shaft and repack my bearings and everything should be ok for the summer. Although, my hopes of putting a Marlin on my transmission are out. Of course, I could use the gear bits as an excuse the replace the gears.
Should I check anything else?
Matt
