Oil help... again

It's kind of like the question " how long does a marriage last ?"

You will get 100 opinions and you can read half of those on this board. I did read this when I was making the same inquiry: really high content zinc oil was not introduced until Chevrolet began making camshafts that had such radical ramp design that the zinc was necessary to minimize cam wear. This was late 60's , obviously well after CAT began making tractors.

By logical inference one can assume the high zinc oil of today ( 1200 ppm if you can find it) was never even available back in the 1950's. Zinc WAS phased out due to shortening the life of cat converters . I found no evidence ( but lots of opinions) that modern oil was "bad" for old cats.

But I'm sure you hear some soon....

Cat 30W trans/drive train oil is good for the clutch and trans. The finals can use 30W maybe even the 50W gear oil. Kendall makes a good 15-40W for the older engines. Or you can check with a bulk oil supplier on diff. brands.

Hi Tim, Congratulations. that is a good looking D8 with what appears to be sealed and lubricated tracks.
I bought a new D6D in 1981, at that time Caterpillar recommended Series 3 engine oil SAE 30 in the engine, SAE 10 in the hydraulic system and SAE 50 in the finals. SAE 50 wt. engine oil is about the same viscosity as SAE 90 gear oil. The reasoning back then was that if the wrong weight engine oil was used to top off from "add" to "full" in any compartment there would be no harm done.
I am sure to catch flack for this but in your case I would still follow this recommendation. Keeping it simple and less expensive is the way to go. I know about drive train oil but in your stated light duty application it isn't necessary.
:fear:
Craig

My oil supplier seriously states NOT to use Low Emission (LE) or it's new replacement in the older engines. They recommend straight 30wt Chevron Delo older type oil. There is one school of thought which I subscribe to which is, 30wt oil manufactured in the late '50's & '60's is now the equivalent of today's 40wt oil. They also say that today's straight 90wt oil has additives in it made for older tractors and those additives are not present in the 80-90wt or the 85-140 multi-viscosity oils.

Like previously stated, you will receive lots of opinions. Call customer service for Chevron Oil Co and ask for the tech dept...

Bob I called the Chev tech line as I was wondering about oil for a T Bird motor as I had their 15/40 Le in my hand from NAPA, he said I was fine with that, then I asked about the older engines he tells me I'm ok with it also, either the Delo 100 for non turbo or the 400 for a turbo engine, I had been a Union customer for 40 years but there is no longer Union in SLO county so I'll end up at Dewers for oils now.

I've had good results using a basic spec 15/40 diesel engine oil ..
No diesel engine will survive on non detergent oil for long ,
due to carbon deposits on pistons !!
,Caterpillar were pioneers of
detetergent oils when they developed their first CI engines
this made them reliable and allowed them to run for 1000's of trouble free hours..
The zinc has been removed from the low SAPs oils used in the latest engines to protect the
emission systems, cats and DPF systems ... this might not be good for our old flat tappet cam shafts!!!

The D8H was built and designed to run on detergent oils, current 15w/40 is fine, for the tranny and clutch use an oil to Cat TDTO spec and anything 30W or above in the final drives. (NOT multigrade in anything but the engine) We ran a fleet of about 60 D8and D9 tractors in the heat of Pakistan with 30w in every compartment back in the early '70's, we had no evidence that it actually shortened final drive life but was better than mixing up the three different oils used across the range of machines we had.

Sure wish there was one right answer to the oil question. But at this time there is part of the answer that has to for sure,WET is better than DRY.


I was told as cheshirecat said Cat has recommended detergent oil since it has been available.


Going to the wet and dry idea as far a finals and transmissions in old gear drive Cats,heavier leaks less than thinner. If I had colder weather to deal with mite have to rethink that for part of the year.

I have decided to use 15W-40 Engine Oil, TO-4 30wt in the transmission and clutch and 80-90 in the finals... Funny thing is today I pulled a couple floor plates and found some more dipsticks.... They are nice and clean looking oil. I think this machine was serviced before it was parked for nearly 20 years.The only one milky is under the seat. Possibility its coming from the winch. My Operators/service manual should be here tomorrow.One I check it, I'll order the oil from the local NAPA store.

I used the 10wt TO-4 in the TD-25C as that is the viscosity they call for in the Torque and tranny.