1968 D15 seriesII rebuild

Our dads D15 developed a knock recently as well as low oil pressure if going down a hill. Charlie pulled it in the shop yesterday and we began to diagnose its issue. He had checked the compression last week and the 2 middle cylinders were around 15 lbs lower than 1 and 4. 132,116,117,134 if I remember correctly. So we went after the oil pressure issue first by dropping the pan. Not good news, the sump pickup was laying in the pan. Unsure how it had come loose from pickup tube as the keeper is still attached. No shavings in the pan which was good news. So that explains the drop in oil pressure going down hill. Engine has never been apart and has been a really good and reliable tractor. Pulled the head to check cylinders only finding a slight ring groove which is normal. Pulled the rod caps and there was some wear but no scouring until we got number 4 piston out. Bearing had some damage but the crank wasn’t gouged. Not taking any chances, will be pulling the crank out to have a look at it. Can’t feel any scouring with a finger but will need to mic it for rebuild kit anyway and possible repair. Haven’t pulled the mains off yet. Looking for suggestions of a good quality rebuild kit, sleeves, pistons, rings, gasket kit.

Alex, who was the manufacturer of the kit you used? I have never heard of having to modify bearings before.

Yes, piston #4 has some side damage probably due to the low oil pressure that occurred while going down hill. The bearing also showed some damage. Other 3 have a little marking on the sides but we are not going to take any chances. While its down she will get the whole rebuild. This tractor has been a work horse for us for 52 years, everything from a 3 bottom plow, disk, corn picker, sickle mower, hay rake duty, bailing hay, pulling the allcrop 60, wagon mover, and any other chore that you can think of. It was dads main tractor until he bought the 6060 in 1981. Used to farm over 200 acres back then. Hopefully our children and grandchildren will get another 50 years out of her.

Edited by Alex09(WI) - 05 Jan 2021 at 6:32pm

We rolled the axle out and used the chain hoist to hold the bolster. Came out fine, no issue really from there. Just a tight squeeze at the power steering assembly. Have the engine out, sleeves removed. Crank definitely needs to be checked.

We put the oil float pickup back on to see how it came off. If the carter key is in a certain position it will slide off. Wear of 52 years has worn it slightly and it will slide by. Really a poor design IMO. Sure caused some serious damage. Piston is from #4 as well as the crank position. A good days work, great spending time with my 2 brothers as we take care of dads 1st AC tractor that he bought new in 1968. No major problems in countered so we are happy. A pretty normal overhaul and she will be ready to go for hay season.

Might want to enlarge the cotter pin hole to use a bigger pin so the pickup doesnt work its way out again. Looking good!

When I had the engine out of my D 15 the oil pump pick up had what looked like steel wool in it ? Does yours ? Thanks !

Rick if you have read the post you know we will need one of your awesome clutch packages while we have it apart.

Edited by AC720Man - 10 Jan 2021 at 4:30pm

AGKITS has the overhaul kit they are Reliance

Robert I just went through your post on your D15 and I must say your a gifted and talented man. Very impressive work. Some good information that we can use for sure. Thanks for letting me know. And can’t wait to see the final product.

AC720Man,

I hate broken bolts, but on equipment as old as we are working on its expected. Good luck getting that rascal out of there! The one I just took out of the F40 had just enough to weld a washer to the bolt then a nut to the washer. I let it cool and worked it back and forth to get it out.