TW35 Water In Oil

FOMOCO Farmer · Oct 15, 2019

I was afraid this day was coming. This tractor is getting water in the oil. I'm suspecting cavitation. I have 5 of these 401s and this is the first one that has done this. Tractor is in very good mechanical condition and all it does is plant and pull the grain buggy. I don't have a lot of money in the tractor so, I plan on rebuilding it this winter. I have rebuilt 2 of these in past years so, I'm not totally in the dark. However, the machine shop I have used in the past is out of business. When I start looking for a machine shop, what do I tell them? The block will have to be bored and then sleeved, correct? Will I need standard pistons? Where do the sleeves come from? New Holland? I know that the back 2 cylinders have to be bored with more clearance than the other 4. Learned this the hard way! Any guidance in this matter will be greatly appreciated.

Bern · Oct 15, 2019

My local machinist has made quite a bit of money in the past sleeving 401 blocks for me. At first he was pressing in the standard thin wall sleeves like NH sells, until I spotted one once with waviness in a cylinder. From then on, he installed thick wall sleeves, and then bored those sleeves back down to standard. I have rebuilt more 401s than I care to count, and each and every time I was able to reuse the pistons.

#6 hole needs to be about 1.5 thou bigger than the other 5, as per factory instructions. What I always did when I got the block back from the machine shop was to line up all the pistons on the bench and measure them. The biggest ones would go in the front, and the smallest ones went in the rear. That way #5 was a little on the sloppy side as well.

If you want info on the sleeves, call Tim @ 36zero-three36-9seven22. Tell him Bernie from the college sent you. He will be glad to help you.

FOMOCO Farmer · Oct 15, 2019

Thanks Bern!! I hope to reuse the pistons as the engine doesn't have a lot of hours on it. Somewhere around 5500 hrs. I'll have the head worked. It has good oil pressure. The injection pump has about 50 hours on it. Injectors will be checked. Clutch is new. It'll be a while before I tear it down. Gotta get the crop harvested. I parked the tractor for fear of ruining the motor. Thanks again.

Bern · Oct 15, 2019

I'd be shocked if you can't re-use the pistons. Check the oil pump carefully while you have it apart, specifically the bore that the relief valve slides in. BIG problem area on those engines.

FOMOCO Farmer · Oct 15, 2019

I'm probably going to put a new oil pump in it. My dad would turn over in his grave if he knew I didn't install a new oil pump. He may if he finds out I reuse the pistons!!

Bern · Oct 15, 2019

Suggest ordering the smaller pump for the TW5 engine. I did that once on a 35, and it still pegged a 100 PSI gauge with cold oil. Those oil pumps are way too big for the application, especially on a 35 that do not have a bypass oil cooler.

Unless it's been seriously overheated in its past, the pistons will go forever in those engines.

TW35 Water In Oil

FOMOCO Farmer

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Bern

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FOMOCO Farmer

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Bern

Well-known Member

FOMOCO Farmer

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Bern

Well-known Member

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