D950 head bolts .. stretch ?

[squarethumps]

I have a Kubota B8200 with the D950 engine. I replaced the head gasket about 4 years ago, and now it is absolutely puking black water out of the exhaust pipe. This is after the shower o' sparks that went flying into the night sky like a Gettysburg fireworks display. I believe that the sparks are from the head gasket itself being destroyed and bits getting into the cylinder.

The first time I did the head gasket job I did not have the head tested or checked for cracks or anything. This time I am going to get it checked and milled or whatever it needs. In any case .. 2 things .. I did not re-torque the head bolts after .. I dunno .. 10 hours or 20 hours of use like I probably ( definitely ) should have. I tried to turn one of the head bolts and it turned ( too ) easily. So the question here is ..after how many hours should I re-torque the head bolts and should I re-torque them on a regular basis ?

The second question I have is -- do the head bolts on these tractors get stretched and should I replace them all ?

Thanks.

 

[Motion]

Four years and how many hours? Was the engine running hot? I would be good to have the head checked. As always check your manual. I don't believe they need to be re-torqued, it certainly wouldn't hurt to replace the head bolts with new from Kubota. Use a thread restorer and clean the bolt holes thoroughly. Do as you feel is best but I like to use Permatex #3 on the head gasket. Be sure to use a little oil on the bolts. Just my .02

 

[squarethumps]

oh ... quite a few hours .. this tractor is the main little work horse for my little farmette. Snow plowing, hauling everything. Probably 500 hours on it, maybe more.

 

[Motion]

I recommend getting the old head off, so the head and cylinders can be thoroughly checked then formulate a plan.

 

[squarethumps]

So I've gotten the head off, and .. I dunno .. the rings of the head gasket looked all in tact, but there did seem to be some missing material on the head gasket. Regardless, the cylinders were filled with water / oil mix. I'm going to take the head to the shop to get tested / worked / etc. The head bolts did come off very easily, almost too easy, making me think that they did come loose, but I'm not sure.

First question :
There's a bit of sludge inside the valve cover so I imagine there is more. What are the best techniques to clean out the oil pan ( without removing it ) and the rest of the block from any of this sludge ?

Second question :
On these 4x4 models I can't imagine I should, but should I have to remove the front drive shaft or otherwise move the shaft housing at the front of the drive shaft in order to remove the oil pan drain plug ? I had to use a wrench and turn the bolt to get it out and the housing was in the way. The bolt was digging in to the housing as it was on it's way out, and I can't understand why that would ever be, but there's no way I'm getting it back in like that. It was digging a good bit / scraping hard on the side of that housing.

Thanks.

 

[squarethumps]

The head is cracked. Anyone know where is the best place to get a new head. I've heard that aftermarket heads are not worth the money, and the best thing to do is get a new OEM head ? Again it's a D-950 engine.

Thanks.

 

[squarethumps]

So a new head from Messicks is like 1150. I'm not afraid to buy it, but I am afraid to buy an aftermarket one from somewhere else. Also -- I'm hesitant to reuse the valves and springs, but I suppose I should really take them off the old head and thoroughly inspect the seats on the valves to look for any pitting or anything that can't be smoothed out with normal lapping. But the springs ... should I just get new ones or should I re-use the old ones and save the $ ?

thanks.

 

[hagrid]

Wow. For $1150 I'd expect the head to come with new valves and springs.

 

[squarethumps]

.. and a reach around.

ya .. It's a chunk of cash. With the freeze plugs, valves, springs, gaskets ( dang head gasket is 80$ ), and new head bolts, the total is around 1500. But I've not found anything that I'd trust at this point. I've dealt with Messicks before, and I've always had good experiences with the quality of parts and the customer service.

and 1500$ is still way less than a new tractor. lol

 

[GeoHorn]

Valve springs DO lose strength over time. If it’s in your budget, I’d install new springs.

 

[dlsmith]

If you have the service manual for the engine, I'd check the go - nogo specs for the springs.
It should give you a certain amount of pressure at a given compressed height. If they meet specs, you can reuse them.

 

[squarethumps]

I doubt I have the tools or measuring devices to gather such accuracy ? I'll do some research and see if I can find that information on how that might be done for a .. second rate garage lol.

 

[leveraddict]

For a few hundred more I would spend the 1500 and get all new parts. Dont want to have problems again after you put it back together!

 

[squarethumps]

So I ordered all the parts for the head including the valves and the springs. I only kept the keepers ( kept the keepers lol ) and the spring retainers and the rocker stuff. Everything else is new, and I'm not even going to take a chance on a mistake, I'm taking it to the shop for assembly. I'm using the old injectors and glow plugs as well. Even though the shop generally works on vehicle engines, they recognized the head the moment I laid it on the counter, so they clearly have experience with them. Until the parts arrive, I'll just wait and work on one of the other 100 projects I have going on lol. Flush the radiator and such. Oh .. the oil plug I described at the beginning of this thread .. I was able to get it back in and it must have been something to do with the way I had the axle on the jack stand or something, because after I placed the tractor on it's wheels, that must have squared up the axle and thusly the front drive shaft with the rest of the tractor, because I was then able to get the oil plug in with no issues. So that's all done. I shudder to think about the sludge that might be in the oil pan. Any good ideas on how to clean that all out without taking off the pan ?

 

[GeoHorn]

. I shudder to think about the sludge that might be in the oil pan. Any good ideas on how to clean that all out without taking off the pan ?

That’s what your filter is for. Don’t worry. Be happy.