'37 D2 Oil Change

Hello,
Working on a family heirloom. Finally got engine running. Now need to know what is the correct oil filter and what type of oil? Brakes & gas tank issues are next on the list.
Thanks for your help.

I put 30 wt valvoline racing oil in my D-2. Look for zddp on the bottle. The old flat tappet engines need that additive so the camshaft will live. There's probably enough of that stuff in the engine after all these years but why take a chance.
If your engine has the add-on bypass oil filter look for a tag or name on the cannister. Otherwise you can pull out the filter and try to match up. I live in a huge ag area so my local full- service auto parts store stocks these in WIX. NAPA is great, too. Find the oldest experienced parts counterman you can.
Modern oil doesn't have the zddp anymore along with some other things because the additives were slowly ruining modern catalytic converters.
Can we see pics of the family heirloom?

I was assuming it would be 30wt, but wondered about it being flathead, additives (zddp), etc... Photos coming soon. Thanks for the info.

I was assuming it would be 30wt, but wondered about it being flathead, additives (zddp), etc... Photos coming soon. Thanks for the info.

30 Wt NON-DETERGENT oil.

This is very important unless you have had the engine down,hot tanked,and put back together. Put modern detergent oil in a old engine and decades of gunk will bust lose and clog your oil passages and even your oil filter.

You can buy it at any NAPA,Advance auto,etc,etc,etc.

In my long career as a mechanic, I have never seen an engine lost to the switch to detergent oil. Detergent oil doesn't "scrub" the inside of the engine, rather it keep dirt an muck in suspension so it can be removed by full flow filters. Older engine didn't have full flow filters, so the bottom of the sump was where most of the junk ended up. Non-detergent oil allows the heavyer stuff to drop out. I'm not saying it can't happen, but that I've never seen it happen.
when I rebearing'd my K-7, I dropped the pan (easy to do) and pulled one cap to see what size bearings it had. I cleaned the pan, then re-installed and ran it for a few weeks until the bearings came in, dropping the pan again , I was very supprised in how much more gunk was washed out, so instead of replaceing the bearing, I cleaned and re-installed the pan for another few weeks, again there was more gunk washed out but less then before, re-bearing'd and it has been fine ever since. I don't know about the GRD, but the BLD uses a "floating oil pick-up, that "floats" off the bottom of the pan, allowing the muck to biuld up there and not effect the rest of the system, it was their way of dealing with it back then.
To expect that the previous owner only put non-detergent oil in since the 50's or so when detergent oil came out is not realistic. More then likely, the "old truck" got whatever oil the owner had on hand at the moment.

I agree.

In my long career as a mechanic, I have never seen an engine lost to the switch to detergent oil. Detergent oil doesn't "scrub" the inside of the engine, rather it keep dirt an muck in suspension so it can be removed by full flow filters. Older engine didn't have full flow filters, so the bottom of the sump was where most of the junk ended up. Non-detergent oil allows the heavyer stuff to drop out. I'm not saying it can't happen, but that I've never seen it happen.
when I rebearing'd my K-7, I dropped the pan (easy to do) and pulled one cap to see what size bearings it had. I cleaned the pan, then re-installed and ran it for a few weeks until the bearings came in, dropping the pan again , I was very supprised in how much more gunk was washed out, so instead of replaceing the bearing, I cleaned and re-installed the pan for another few weeks, again there was more gunk washed out but less then before, re-bearing'd and it has been fine ever since. I don't know about the GRD, but the BLD uses a "floating oil pick-up, that "floats" off the bottom of the pan, allowing the muck to biuld up there and not effect the rest of the system, it was their way of dealing with it back then.
To expect that the previous owner only put non-detergent oil in since the 50's or so when detergent oil came out is not realistic. More then likely, the "old truck" got whatever oil the owner had on hand at the moment.

I remember in the 50's when they started using detergent oil it was common to have engine bearing problems as the detergent would remove the carbon buildup from the bearings that kept the clearances and they would then start to 'rattle or knock'. I think this happened more in the babbited bearings common then.

Not completely on subject but as a mechanic we've used high detergent cleaners like BG Products on customer's vehicles.
New vehicles hydraulically change cam timing wih oil pressure.
No one seems to want to change oil regularly and valve timing gets stuck.
This cleaner will allow the cam timing to change again.
However, it will also plug up the oil screen in the bottom of the pan!
I wouldn't leave this stuff in a dirty engine for more than a few minutes.

In my long career as a mechanic, I have never seen an engine lost to the switch to detergent oil. Detergent oil doesn't "scrub" the inside of the engine, rather it keep dirt an muck in suspension so it can be removed by full flow filters. Older engine didn't have full flow filters, so the bottom of the sump was where most of the junk ended up. Non-detergent oil allows the heavyer stuff to drop out. I'm not saying it can't happen, but that I've never seen it happen.

When I bought my 1957 Ford tractor it was holding 40 psi with no smoke,and I couldn't figure out why the landscaper that sold it to me (young guy) had put it up for sale and bought one of those new little dozers with the arms that lift the bucket overhead.

I mostly used it to pull and power a bush hog once every couple of weeks,or to move stuff around in the yard,so it took a while for the oil pressure to drop. It gradually dropped down to around 5 psi,and I figured I needed crank kit and the previous owner had STP'ed it to death to get oil pressure to sell it.

Since I needed to use it right then I decided to just change the oil and filter (both looked new when I bought it) and see if that helped. When I unscrewed the oil filter from the side of the block it was so heavy I couldn't believe it. Evidentially the previous owner had changed the oil and filter when he bought it,and panicked when the oil pressure started dropping,and then changed it again to sell the tractor because once I put a new filter on there and filled it with 30wt non-detergent oil,the oil pressure went up to 50 psi at idle warmed up. It started to drop again after running it for several hours,so I just changed the filter again and added a quart of 30 wt non-detergent,and haven't had a minutes worth of trouble with it since.