Re: [A/S] Truck maintanance

["Jim Dunmyer" <jdunmyer@xxxxxxxxxxx>]

Patti,
 There is no doubt that Synthetic oils are better. I run Syn in my
differential, but don't in the auto tranny or engine; here's why:

The transmission oil is developed by the manufacturer to work with their
transmission. There are characteristics of the oil that make the clutches
work as they're supposed to, and I'm not at all sure that a "universal"
tranny lube will do the job. Its main claim to fame is ability to stand more
heat without breaking down, but I figure that the cooler will keep the
regular oil cool enough to prevent that.

Engine oil: Synthetic is far better, but the main benefit that I see (to
offset the much higher price) is that you can run extended change intervals.
HOWEVER, if you do so, you really should pull a sample every 3-4 thousand
miles and have it analyzed. Add that cost, and you might as well change it.
OTR trucks (semis) run extended change intervals, using analysis, but they
have several times as much oil in the pan, so it becomes worthwhile.

Like Jim Smith, I've driven a number of Diesels for long mileages, mine
being VWs. I overhauled the engine of my '91 Jetta at 261,000 miles, and
found the bottom end to be like-new; I actually considered reinstalling the
original bearings. However, the cylinders were worn at the very top. Now,
MAYBE using Syn oil would have cut that wear, I don't know. It certainly
couldn't have done a better job in the bottom end because you  can't beat
perfect.

I don't generally believe in oil or fuel additives, but have used the latter
if I felt that I had problems that might be helped. (gummy injector or
pump..it's several long stories..) I also don't generally believe in
"chipping" engines or using aftermarket filters. The manufacturer designed
our trucks to the best of his ability at the time, if they felt that a
"chip" would help, they'd put it in at the factory. You will nearly ALWAYS
loose something when you mess with this stuff, mostly long-term reliability.
If you keep your foot out of it (IE: don't use that extra performance), you
won't affect wear & tear, but then why have it?

                                                        <<Jim>>