Can I use 15W-40 diesel engine oil in a 450-B dozer?

[Pushrod]

The manual calls for two different oils, one for winter and one for summer use with the dividing line temperature being 32 degrees F. In the winter in WV we can have days on both sides of that line. I'm guessing they didn't have the multi-viscosity oil available in the mid-70's that they have now and was wondering if I could use something like the 15W-40 year round in the dozer instead of the SAE 30W in summer and then switching to a lighter viscocity in the winter (which wouldn't be good for the days above freezing).

[Lavoy]

Yes, by all means. Keep in mind, that manual is 40 years old or so, and oil technology has changed.
Lavoy

[Pushrod]

Thank you. That is what I thought.

[Frankdozer]

I have a similar question in that can I use full synthetic oil in my 1984 John Deere 455D crawler loader? And would I use 15w-40 for year round use..Thanks, Frank

[Lavoy]

Synthetic will likely be a 5W-40, but yes you can.
Lavoy

[crawler123]

I've got 15-40 rotella in mine. But in Montana winters it's not going to start unless you got some kind of block heater arrangement.