pictures of d4 or rd4??/

oh duh ... the number is 4G 4637 W.

its a 1937 RD4

that's very good to know.... lazyfarm was kind enough to look up some info also and we were thinking it might be a very early D4... but it has no tags on the radiator and no holes were they might have been affixed, so it made it a bit iffy. He did state that the serial number was within a set of numbers that are said to be in the sequence when Cat changed from the R to D4. Actually the number on our Cat is only 179 from the first of the "Magic" numbers.... so it made it a bit exciting to think we have one of the first "D" series... apparently the 4G was of some signifigance and the W at the end denoted a extra wide unit and of course it has the wide tracks making for a pretty stable platform.... anyway thanks ,,, the reason for all the research is I'm trying to find a schedule for lube and the like.... nice site by the way, informed thanks again.... Doug

it could be an early D4 but my information says that all 4G series tractor were RD4 with the first D4 to start with the 7J series.
Someone else will need to confirm.
I do not have anything stating what the exact tractor number was when the "R" was dropped from the RD4

I know a local company that has a 4G4770 RD-4, so they went at least that high with the RD-4's.

thank you... now that gets us much closer ,,,, so I would have to suspect it is an RD4... cool.... any thoughts on why there are none of the markings therein... I still have not found any drill holes for attachment of emblems of tags of any kind around the Radiator.... being as now it's time to start power washing it ,,, be interested to see what else shows up.... by the way when one goes to start a D4 is the lever directly below the pony motor supposed to be engaged or pulled up before starting the pony motor,.... because it sure is hard to get it to pull up after the pony is running and yet sometimes you can't get it to engage before starting the pony.... Doug

Possibly the Radiator has been replaced with a later one.
With the pony pinion , the other lever is the clutch ,Engage it one way the other way to disengage , If it is adjusted right,pull the lever to engage the Clutch brake , That makes emgaging the pinion easier .

it could be an early D4 but my information says that all 4G series tractor were RD4 with the first D4 to start with the 7J series.
Someone else will need to confirm.
I do not have anything stating what the exact tractor number was when the "R" was dropped from the RD4

[quote="chriscokid"]it could be an early D4 but my information says that all 4G series tractor were RD4 with the first D4 to start with the 7J series.
Someone else will need to confirm.
I do not have anything stating what the exact tractor number was when the "R" was dropped from the RD4[/quote]

I'm not sure where the change to D4 was, but both my 4G's are D4. Our old 4g that has been the family since new is in the 8000 SN range. No radiator change. The other one is about 75 numbers away it's a D4 as well. I'm not sure on its history but it sure looks unaltered.

It would be interesting to know when the change happened

Bp