Model 60 with coolant in one cylinder

[Tom Schaech]

Hi everyone...
I"d like some input from folks who have more experience working on these than I do--my business is air-cooled small engines.

I recently bought a JD60 NFE. PO told me they were sure the head gasket was blown--found coolant behind one spark plug. Got it into the shop, tore it down. Found neoprene part of gasket badly shriveled. Little water and surface rust in left cylinder. Cleaned all up, installed new gasket and reassembled. Fired up easily enough, but spit coolant out of the exhaust for a few minutes. Thinking it had to warm up and seal well, let it run for a while. Shut it down and started next day; same thing.

Pulled back into shop and tore down again. Found small amount of coolant on top of left piston. No external leaks of any kind, no oil in coolant when drained both after getting it and before this recent teardown.Changed oil during initial rebuild; no water in oil.

I"m thinking either I didn"t properly torque gasket or crack in cylinder head. Inspected block for cracks in cylinder sleeves--none. No crack between cylinders. Took the head to a machine shop and am awaiting report.

I read somewhere that 60s were "famous" for cracks in block. Any thoughts or experience here? There are no welds or anything that I can find to indicate a freeze crack.

Would appreciate any feedback!


Thanks!

Tom

 

[Anonymous-0]

Tom....the JD60's I've seen with cracked blocks have small cracks in the cylinder bore near where the stud bolts are located. Almost as if someone over torqued the head bolts/nuts and the stud is being pulled out of the block and cracking the block in the process. JD60's are also noted for loose clutch drivers that eventually ruin the crankshaft splines.

 

[toot]

Should be torqued 150 ft lbs. work from center stud out, try some good stop leak. Dont go jerking blocks out yet.. check around studs for stress cracking from overtightening. Use a light coat of permetex 3 on gasket.. recheck torque after running. The 60 block is virtually the same as a late "A".. heard other stories bout 60 probs, but never heard that.

 

[Mike Aylward]

The 60 tractors are not "known" for having loose clutch drivers. They are known for having operators that let them get loose. They do not have an inherent problem with these anymore than any other two-cylinder tractor. Lack of maintenance is the problem. Mike

 

[ramtuff]

Had the exact same problem.Did the same thing you did.I took the guy"s word for it,he said it was the head gasket.The 2nd time I tore it down I took a mirror,found block cracked 1 inch down 2in. long from top.Pulled engine had it bored an sleeved to std.No problems for 10yrs,When you torque the head back,let up about 10lbs on the center head bolts.I"ve heard over torquing the middle bolts will crack the block.

 

[Larry in WNY]

If you remove the studs use permatex sealant on the threads in the block and lead washers on the nuts. Some use permatex or copper coating on the head gasket too. A John Deere mechanic said they put them on dry so that's what I did on my 60. So far it's still good. The head and block need to be fairly flat to seal well. Torque the nuts in increments (25, 50, 75 100, 125, 150 ft/lbs etc) in the pattern from service manuals. Hopefully, you won't find any cracks in it. I'm not sure if the gasket should be re-used once compressed. Maybe others have experience with that.

Larry

 

[Tom Schaech]

Everyone:

Thanks for the replies. I feel I"m on the correct track. I will apply Permatex #3 to the gasket before reassembly (whichever head I can use or purchase).

I will post the results once complete.

In the mean time, any additional comments most welcome!!


Thanks again to all!!

Tom