Case 680CK-B Need Piston

[pre-emissu]

Hello. I have a 1969 Case 680ckb backhoe with a 267 cubic inch diesel engine. #3 piston was melted yet the backhoe would start right up and dig a lot. My understanding is this machine had a three year production run ending in 1969. Late in the production cycle some changes were made to the piston and rod. Early models had a 1.358" wrist pin. My piston has a 1.5" wrist pin. I'm searching hi and lo for a new or used piston to replace the destroyed one but no luck. I have a kit with new pistons but they have the smaller wrist pin. My rods accept a 1.5" wrist pin. If I can't locate a piston I am considering having the new pistons machined to accept the 1.5" wrist pin or having custom machined bronze bushings that will allow me to use my rods with the new pistons. The original part # of the piston for my machine is A24488. The serial plate is missing off the engine. The tractor serial # is 9103232. This is an inframe build and I am currently changing the main crankshaft bearings. Thank you and I look forward to suggestions and advice.

 

[Alan]

That engine still running strong after melting a piston says something about how tough those old diesels were built. Machining the new pistons or making bushings both sound like real options if you can't track down an original. Would you be able to post a photo of the melted piston and the two rods side by side so we can see the size difference?

 

[pre-emissu]

That engine still running strong after melting a piston says something about how tough those old diesels were built. Machining the new pistons or making bushings both sound like real options if you can't track down an original. Would you be able to post a photo of the melted piston and the two rods side by side so we can see the size difference?

 

[pre-emissu]

A third option could be to replace the piston rods to the ones that accept the 1.358" wrist pins. That would eliminate these problems. All other dimensions are the same. Notice the rod does not have a hole for oiling the wrist pin. Maybe that's why the piston got smoked. The earlier version has that hole.