Type of Oil

[Polverone]

I just picked up my M35A2 from GL and I am getting my feet wet with getting all the knowledge needed. I was lucky enough to get all the old service records with it and they go back as far as 1987 - plus the engine tag lists manufacture as 8-87. By that I figure I ended up with a 1987. And yes, she does whistle (loudly at RPM) to me when I fire it up.

23,581 miles and 953 hours. Looks great with very little rust (on the hardtop only) and new vinyl cargo cover.

I dug through some of the old posts and found a little info on changing my oil.

I read where you can get/use Shell Rotella 15w-40 and available at Wal Mart for $35.00 for 6 gals.
Does this sound right?

What brand make weight of synthetic have you had experience with?
I think I want to try that option.

Also is there a better way to search the arvhives? I tried "Oil", "Change Oil", "Lubrication", without too frutiful a result.
Thank you for any info

 

[cranetruck]

I have used Rotella and it cranks a bit faster in the winter time, but have gone back to 30W (Texaco Ursa).
This is from the mil-veh list:


From : Mil-Veh Co. <milveh@sbcglobal.net>
Sent : Friday, December 17, 2004 12:47 PM
To : "Military Vehicles Mailing List" <mil-veh@mil-veh.org>
Subject : Re: [MV] Motor oils and cold weather trip


| | |

I know we've discussed this at great length before,
however it is probably worth repeating for those new
to the list or in case you missed before.

The spread of multi-grade particularly in a diesel
engine should generally NOT be far apart as in a 15-40
grade Rotella or otherwise and I know a lot of you
love your 15-40 oil, but please read on...

Binders or polymers are used in the formulation of
multigrades and they don't lubricate, its not their
job. "Multi viscosity oils work like this: Polymers
are added to a light base (5W, 10W, 20W), which
prevent the oil from thinning as much as it warms up.
At cold temperatures the polymers are coiled up and
allow the oil to flow as their low numbers indicate.

As the oil warms up the polymers begin to unwind into
long chains that prevent the oil from thinning as much
as it normally would. The result is that at 100
degrees C the oil has thinned only as much as the
higher viscosity number indicates. Another way of
looking at multi-vis oils is to think of a 20W-50 as a
20 weight oil that will not thin more than a 50 weight
would when hot.

Always use a multi grade with the narrowest span of
viscosity that is appropriate for the temperatures you
are going to encounter.

In the winter base your decision on the lowest
temperature you will encounter, in the summer, the
highest temperature you expect. The polymers can shear
and burn forming deposits that can cause ring sticking
and other problems.

10W-40 and 5W-30 require a lot of polymers (synthetics
excluded) to achieve that range. This has caused
problems in diesel engines, but fewer polymers are
better for all engines.

The wide viscosity range oils, in general, are more
prone to viscosity and thermal breakdown due to the
high polymer content. It is the oil that lubricates,
not the additives. Oils that can do their job with the
fewest additives are the best.

Very few manufactures recommend 10W-40 any more, and
some threaten to void warranties if it is used. It was
not included in this article for that reason. 20W-50
is the same 30 point spread, but because it starts
with a heavier base it requires less viscosity index
improvers (polymers) to do the job. AMSOIL can
formulate their 10W-30 and 15W-40 with no viscosity
index improvers but uses some in the 10W-40 and 5W-30.
Mobil 1 uses no viscosity improvers in their 5W-30,
and I assume the new 10W-30. Follow your
manufacturer's recommendations as to which weights are
appropriate for your vehicle".

Are you a believer yet? The bottom line here is the
more binders the less protection you have with a
sheering factor* or at the point where oil can
effectively seperate the two bearing surfaces that it
was designed to lubricate by seperation.

If you still need more info. read on....not all
diesels are created equal and the army has gone to
great length to determine which oils will offer
maximum service. I suggest you always use what is
recommended, forget testimonial evidence, thats junk
is reserved for diet ad claims, not your precious
motor oil.

*At 100C the range of kinematic viscosity falls into
each SAE viscosity grade. This system was developed
years ago and is technically obsolete, however, the
general public is so familiar with it that it remains
today.

How the engine reacts to oil at a high temperature is
measured by the "high temperature, high shear" (HTHS)
viscosity. This value directly correlates to the oil
film thickness in a bearing as I noted above. And this
brings up why you want to use the right oil for your
mil-veh.

If you tend to drive faster or under heavy load, you
will increase the under-hood temperatures and in the
newer military engines there is tighter engineering
tolerances and this makes oil critical. Using the
wrong oil means you have a greater chance at
overworking engine oils.

That overworked oil can change in chemical makeup into
a sort of tar-like substance. This blocks oil channels
in the engine and will likely cause the engine to
seize up, not fun.

So when farmer Ed says, "Heck, I been usin 15-40 in my
diesels for 30 years without a problem when the mfg
called for 30 wt, then its only because those oils
never reached critical load. The difference between
overworked and stable is slight at high operating
speeds and loads, so why risk it just to be different?


Use what the manual tells you too! If your engine
calls for 15-40, fine then use it because the mfg. has
tested your sloppy engine tolerances and puny load
ranges and your underpower-dog of an engine can handle
it,(I'm just kidding with ya) but if the mfg. says use
30 wt. or even a 15-30, then don't be cute and use
10-40!!!!!!! You're only asking for trouble.

If you have finished reading this in its entirety you
now know more about oils than 99% of the public,
congratulations!

 

[Armada]

GREAT info Bjorn!!


Congrats Polverone on the new addition! That's great that you were able to get the service records too!

Mine is almost identical to yours as far as run time. 23,919 miles and 948 hours on it when I picked it up from GL.

There were no rebuild tags on the engine.

 

[M543A2]

Interesting information about the oil. Thank you Bjorn for taking the time to present the information that is hard to find anywhere else. Multi grade oils have changed a lot in recent years. Interesting also that the engine in my son's M35A2, my M543A2 wrecker miltifuel engine, my dump truck multifuel, and the miltifuel engine in my road tractor all have stenciled on the valve cover "15-40 oil". I am farmer Marti, and we use Rotella 15-40 in everything we have with no trouble, and we do not baby them. We also do all of our own mechanical work, so we do not like to risk trouble. My Dodge Cummins 5.9 went 300,000 on 15-40 before rebuild because a piston was cracked. The crank journals checked out within standard tolerance, did not need polished. The truck is used regularly to tow 10,000 to 16,000 pound tractors and equipment on a flatbed trailer, and the engine has had the pump turned up, special injectors, and LP injection. I guess it is like my oil distributor said: "Recommend anything to a customer, but never, never try to change his ideas about an oil he has had success with". Please understand I am not trying to discredit the information presented on oil. Follow the recommendations of the mfg. and do not go too low on the bottom end of the viscosity index. I am speaking from two generations experience with Rotella 15-40, which may be different from others because of how we do things.

 

[Polverone]

That is great information Bjorn. Thank you for taking the time and effort to give us this knowledge. That post should go under the tips and tricks as a sticky for sure.

From what I gather the 15w-40 is ok. It is also marked on top of my valve cover with a label "Use Only 15w-40"
Living on the West Coast our weater reports are rather boring - unless we are getting record rainfall. Pretty stable.
To avoid the multiviscosity variance I assume that I could use a straight 30 weight as the manual calls for?
But what puzzles me is that it only says OE SAE 30. (I assume Original Equipment SAE 30 wt)
One thing my local mechanic tells me is that there are different grades or classifications of oil - especially for diesel engines.
Something to the effect of " CS3/M, TBN, CF-4" type of designiations along with the weight

That was another one of my concerns about using the synthetic. What grade designation?


Thanks again Bjorn - great info.

 

[M543A2]

I took a look at the specifications for Shell Rotella T 15/40. The current diesel oil spec is "Cl-4". Look for this and "SJ"on any oil you use in a diesel. Shell 15/40 is rated "Cl-4Plus, Cl-4, CH-4, CG-4, CF-4, CF/SJ, SL. It lists heavy truck mfg. requirements met, farm equipment mfg. requirements met, diesel and gas pickup mfg. requirements met, construction equipment mfg. requirements met, etc. in some detail on the container. Companies named are Cat, Detroit (4 cycle), Mack, Mercedes, Volvo, Deere, Case, Massey Ferguson, New Holland, Ford, GMC, Dodge, Toyota, Nissan, Komatsu, and others. Multigrades have come a long way in the last few years. I think we can use it in our trucks with no problem. It is certified to meet the requirements of the manufacturers of well known names of engines.

 

[jasonjc]

after reading what bjorn said about the muit type oils I ford some HEAVY DUTY SAE 30 Rotella T and it meets all of of the above sepc's plus MIL-L-2104F.
and its the same price

Jason

 

[ironhorsethegeneral]

Hi. If you would like to know more about Synthetics look under the post called "OIL AND WHAT IS GO GRADE". We told people about synthetics on this post.