ID aftermarket D1105 head?

[Mogman]

As hard as I tried not to I have relented to repairing my sisters RTV1140. (D1105)
It has had a constant history of overheating and even though it has a gauge that does not "save" it....
It obviously has a combustion/cooling system leak but fortunately no water in the oil at this point so it does not look too serious.
The head gasket has been replaced a couple time and the head once.
I am curious how to ID whether the head is aftermarket, and if aftermarket heads give reasonable service.
I am going to go through the entire cooling system but it appears by the "story" the fan fails to run at times.
I think I am going to try and find another place to put an over temp switch in and connect it to a loud horn that cannot be ignored.
Any more tips on this issue would be welcome also.

 

[Mogman]

So nobody has any idea how to ID an aftermarket head? That make me real confident when I head down to the local dealer and lay down $1600 for a head he can get in 4 days for $300 off of ebay, no incentive to cheat there....

 

[North Idaho Wolfman]

So nobody has any idea how to ID an aftermarket head? That make me real confident when I head down to the local dealer and lay down $1600 for a head he can get in 4 days for $300 off of ebay, no incentive to cheat there....

A genuine Kubota head will have the Kubota cast mark on it.
But aftermarket heads can be just as good, just depends where you get it from.

 

[cthomas]

I would verify the radiator is not plugged and take the head to a machine shop to verify it is not cracked and straight. No need to replace the head if it passes. Also take a straight edge and check the block while the head is off. Aftermarket suppliers can be good just depends on the source.

 

[Russell King]

If you have a dealer that is local you could ask them to show you the engine head on a new RTV and see what you see on the head to indicate that it is Kubota part.

Or see if the have a head in stock in the parts department to look at

 

[Mogman]

A genuine Kubota head will have the Kubota cast mark on it.
But aftermarket heads can be just as good, just depends where you get it from.

Do you have an image of this mark?

 

[North Idaho Wolfman]

Circle with a K in it or just a K

 

[Mogman]

I would verify the radiator is not plugged and take the head to a machine shop to verify it is not cracked and straight. No need to replace the head if it passes. Also take a straight edge and check the block while the head is off. Aftermarket suppliers can be good just depends on the source.

Any reputable sources?

 

[Mogman]

I would verify the radiator is not plugged and take the head to a machine shop to verify it is not cracked and straight. No need to replace the head if it passes. Also take a straight edge and check the block while the head is off. Aftermarket suppliers can be good just depends on the source.

What is the max deck warpage? I cannot find that spec.

 

[Mogman]

The deck has no warpage that I can find neither does the head.
I am going to take the head to my machinist and have him give it a once over and put it back together with factory gaskets, the head was bought as a kit so it likely had aftermarket gaskets.

 

[North Idaho Wolfman]

The deck has no warpage that I can find neither does the head.
I am going to take the head to my machinist and have him give it a once over and put it back together with factory gaskets, the head was bought as a kit so it likely had aftermarket gaskets.

Yea most aftermarket heads are fine, but the aftermarket gaskets are almost always poo poo!

 

[GeoHorn]

A genuine Kubota head will cost $1600+ and a cheap aftermarket will be less.



(sorry….couldn’t resist..)

 

[Mogman]

When the manual say to "re-torque" the head after 30 min. do they mean to confirm torque or actually back the bolts off which would be the literal translation of "re-torque"
And I assume they mean cold yes?

 

[whitetiger]

Confirm and with the engine cold.

 

[Mogman]

Confirm and with the engine cold.

Ah a fellow B7100 owner, I have had a B7100D for 32 years, a little rough on the outside but runs like a charm, a new seat every 5-10 years and she still works for me on a regular basis.

 

[Daferris]

Another idea is to get another fan switch and wire it up as a kill switch if the engine overheats. Just has to be at a higher temp than the fan switch. Yet another idea is to wire run whenever the engine is running. Of course both of those assume the radiator, hoses and thermostat are clean and operating as they should.

 

[Mogman]

Another idea is to get another fan switch and wire it up as a kill switch if the engine overheats. Just has to be at a higher temp than the fan switch. Yet another idea is to wire run whenever the engine is running. Of course both of those assume the radiator, hoses and thermostat are clean and operating as they should.

I cannot find any reason this would have overheated, the fan switch and fan circuit are working fine.
The radiator looks fine.
I think they had a bad fan relay originally and cracked the head after chasing the problem.
Then they installed an aftermarket head and gaskets that lasted two years, I think the head gasket just blew.
They are hung up on the fact that the temp gauge would say it was overheating but the fan was not coming on.
After the head gasket blew this would not surprise me as the temp sending unit was on the back of the head and the fan switch is in the thermostat housing, they said it would overheat almost immediately, within driving a few hundred feet, again not surprising with hot combustion gasses filling the cooling passages in the head.
My machinist called after only two days and said the head was ready, I will not be able to pick it up until Wed. but he must not have found much wrong with it, I ordered all new factory gaskets and hoses, a little pricey but I think it will be worth it.

 

[Mogman]

Well after doing allot of research I decided to actually re-torque the head, going in the original sequence, breaking each one loose about a quarter turn then back to the original torque, I was shocked at how much farther each bolt went, about one flat. (1/6 turn) each
I guess time will tell if that was a good move or not.