Re: Synthetic oil in Series 3 gearbox: seals OK for synthetic use?
Posted by Cees Willig on December 28, 1999 at 19:31:46:
In Reply to: Synthetic oil in Series 3 gearbox posted by Barry Benson on December 27, 1999 at 16:16:31:
Hi,
Please check if seals are OK for synthetic oil. If not then it may be likely to quickly develop oil sweats or leaks.
For some reflections on gearbox mission life: please see longer answer at 'gearbox whine' some entries below.
Some experiences:
Experience with overhauled older 4 cyl. MG engine, first filling synthetic: did not sweat but leak, applying 10Wx non-synthetic: no leaks, no sweats.
Using 0W40 in SAAB 900 Coupe Classic Full Pressure Turbo (I enjoyed the 900 FPT 26500 km last year while our LR 110 of 1983 received its MidLife Upgrade): sweats oil, using 10W40 non synthetic: no sweats.
Same with our 200Tdi: Mobil 10W40 synthetic (right from start used): dry, Mobil 0W40 Synthetic: slightly sweating at clutch area as well at (very mild sweat) some other areas through gaskets. However: 0W40 improves winter starts (higher revs at cold cranking, etc.).
It mostly comes down to
* Is seal material suitable, does it swell more or less than with non-synthetic.
* Best is to use selected oil type / make right from the start and do not change at later stage (except from dedicated single grade un-doped mineral oil for initial engine break-in): seals settle at constant swelling.
Note that often for ship diesel engines the oil spec/ make is kept as constant as possible during engine's mission life as whole engine is setting itself to the oil.
Succes
