Farmall 560 and 660 Diesels

I later got an IH technician involved in pump settings and we achived 105 hp at 2200 rpm. We later cut it back to 90 hp and ran it that way for 11,000 hours. At 11,000 hours it did deposit a couple of pistons in the middle of barn yard, on a silo blower. Interesting part on that one is it was an aftermarket piston and sleeve kit with only very few hours that blew up. I've never been sure whether piston and sleeve kit or the rebuilder was the problem. 560 was still the most economical hp I've ever run. We got a lot more hours out of 656, however it was all at 2000 rpm and 65 hp.

The bottom line is, I've never made as much profit in a given year, as I did in the late 60s, early 70s farming with 560D and 656D. I've never matched it in actual dollars since, let alone give consideration for inflation.

I'm not positive on the specifics, but the 660 was a heavier tractor with different planetary style final drives. Wardner and others can give ya the details as to exactly what the 660 rearend was.

You probably knew that, just thought I'd point it out in case anyone reading wasn't familiar with 660's.

The increased RPM of the 660 is offset with the planetary hubs at the end of the axles. 560's and the 660 have nearly the same top speed. I read somewhere recently that the planetary setup adds 1500 lbs to the 660.

So basically the 660 is different in the taller hood at front of tractor due to the larger radiator. Extension on the cowl dog legs were attached with spot welds. The grill is the same but a cast iron spacer is added beneath it. The badge is obviously different. The fan and shroud are different. Everything else remains the same until you get to the axle shafts, their housings, hubs, wheels, wheel weights, and tires. Attachments like drawbars may be different but I don't know. They are confusing. The 650 (not a typo) and 660 use the same draw bar but carry different numbers. The drawbar struts on the two tractors are certainly different.

One would have to assume that both tractors were built on the same line. At some point, somebody must have adjusted the pumps for the tractor they were installed on.

I think it is safe to say that a 560 and 660 will test nearly the same at the same RPM.

The only differences in the power units that I know of are the radiator and the fan. The 660's radiator is three inches taller. The 560 uses a five bladed fan and the 660 uses a six bladed fan. BTW, I could use a 660 fan. I am currently using a four bladed M fan which works well. I suppose I could find the right fan on a 656 or 706.

Speaking of fans, I was surprised to find that my fanbelt appears to be original. It has an IH part # and traces of red overspray. I am installing a Fisher snowplow pump and had to change it last week.