Unimog hub temperatures

#16
If it's the U1300L portals then both front and rear portals migrate oil due to high speed driving. On the fronts, I'm not even sure it takes very long for the migration to occur so don't assume it's distance related. The rear portals lose oil for two reasons, one is migration through the vent, the other is that the inner seal is damaged. These portals were not designed for 100kmph and bigger tyres, but that's how we choose to drive our trucks so all of us U1300L owners need to find a solution. The early U1550L/U1350L and SEE portals are roughly the same casings, but they have much stronger bearings. The lower, outer bearing goes from 11mm to 14mm requiring a different gear and wear ring. The lower inner and upper bearings go from ball bearings to better quality roller bearings. These are worthwhile modifications.

The VGE 3.0 product is a proven solution and keeps the 300ml inside the portal where it's most needed. Jostt's reservoirs are very interesting. When the gears spin and lift the oil, is there any way of determining how much stays in the portal and how much in the reservoir?

I drain my portals every time I change the engine oil, so every 8,000kms. That's how I picked up the LHS rear failure, recently the RHS rear failure and the beginning of the RHS front failure. The LHS front is leaking at the inner seal. For the U1300L portals we only need 1.2l of oil in total so price isn't a barrier. What is the worlds best hypoid, low foaming, GL5, final drive oil available that can withstand constant high temperature running?

Good oil, HD bearings, resolved venting, new seals and regular servicing should do the trick........I hope!
 
#17
Hi Charlie, what sensors does the Atlas system come with? I have a Blue Sea systems temperature monitor and I used epoxy glue to stick on the sensor to the portal casing. I had the rear brake pad get stuck, causimg the temperature to risequite a bit, got to 70 Deg C by the time I found a safe place to pull over. Normal temps are about 20 Deg C above ambient aand the front ones are normally around ambient unless I've been braking.

View attachment 453977
Thermocouples that go into the drain plug holes.