Rant on Oil
Use Synthetic!
That said...
We started using a 0W30 Esso Synthetic oil in all of our engines
because it made them start so much easier in the winter. Then,
Walmart stopped carrying it and the only way we could get it here was
by the litre at the gas station which proved prohibitively expensive.
We then switched to Esso Delvac 1 5w40 synthetic. It's
still expensive, but the UniMoG only gets it's oil changed 2 or 3
times per year, so it's reasonable and we get a good temperature
range. This is convenient since we can see a 30 degree Celsius
temperature change in a week long trip where we go.
We used to use Amsoil synthetic gear lube in the MOG just to give the
gear box as much help as possible. Mercedes does not recommend
this however because the seals aren't designed for it which causes
excessive leakage. We monitored the consumption carefully and
calculated the annual cost of the fluid. It did not break the
bank.
After we replaced the transmission, we switched to Pennzoil GL-4 for a
while. This was based on further research into the various oils
and their effects on the vintage gear boxes. When you have just
purchased a new UniMoG transmission, you think carefully how to make
it last. The material specification from the oil manufacturer
specifically states that the GL-4 oils will not cause problems with
bronze bushings. (Here
is the link to the Pennzoil data sheet)
We had also noticed that once we started using Amsoil in our old
transmission, the syncros got much worse! The evidence suggests
that the Amsoil was either attacking the syncro ring material like a
conventional GL-5 oil, or it was too slippery and did not provide
enough friction for the syncros to operate properly. Either way,
we were not happy with the results. After switching to GL-4 in
Giggles, we were able to perceive in improvement in the operation of
the syncros, so all may not be lost if you've made the mistake of
using GL-5 in your old gearbox for a while.
In the new transmission, all six syncros work great and at 11,000 km,
the gear box was not losing a drop of oil in a 4,400 km trip! (not bad
for a German vehicle.) We did notice, however, that the gearbox
runs a little hotter than the old one. Maybe this is because it
is new with close tolerances, or maybe the Amsoil gave an advantage.
At this point we are willing to drive slower to reduce the heat
and have good syncros and no oil leaks. We also now change our
transmission oil once a year whether it needs it or not.
In 2005 we changed all of our oils (in everything we do the oil
changes on) to Royal Purple Synthetics. We were able to get the
oil at a screaming hot deal! The oil temperature on the
transmission improved with the switch and the syncros seem to still be
happy. The transmission began to slowly lose the top 1/2 litre
of oil somewhat quickly, but kept the rest in the gearbox for extended
periods of time.
In 2010 we changed back to Amsoil after losing the opportunity to get
dealer pricing on Royal Purple. SAE
10W-40 Synthetic Premium Protection Motor Oil is appropriate for
use in Gasoline, Diesel, and Motorcycle engines, so we've been able to
standardize on one engine oil for the Mog, Sprinter, and bikes -
Amazing!!!
Here are good web sites for oil
comparisons and oil
filter comparisons