640 Differential cover

[Joe_R]

I have a small leak from this cover under my 640 differential. However, I'm unsure of what is behind this cover. Can you tell me it's purpose. I have drained the oil. But can I just remove the five nuts to replace the gasket? Thank you.

 

[shaun wallace]

So happens that is the hyd system. That cover is stuck on VERY good, have not seen one that didnt have to chisel off . The weld bump is a stud up inside with oring on it. I would look very hard for leak somewhere else, that is just where it drips.

 

[Sean in PA]

I believe that's where the relief valve for the 3 point hydraulics is located.

 

[pomester]

That plate covers the pressure relief valve. There is a gasket and O-rings. As has been noted, it's usually on quite tight.

 

[Joe_R]

So happens that is the hyd system. That cover is stuck on VERY good, have not seen one that didnt have to chisel off . The weld bump is a stud up inside with oring on it. I would look very hard for leak somewhere else, that is just where it drip

Glad I asked before trying. I'll look around for a possible leak elsewhere. That is the lowest point and perhaps it's just dripping off of that point. At my age it's a little difficult to get a good look under there. Going down isn't a problem. But getting up can be. Ha-ha. Thank you for the information.

 

[Joe_R]

That plate covers the pressure relief valve. There is a gasket and O-rings. As has been noted, it's usually on quite tight.
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View attachment 2759

Thank you for the diagram. Now I know what's going on in there. Glad I didn't attempt to remove the cover. From the other response it doesn't sound like a leak around there is very likely. Probably something else leaking from above and dripping off of that area. I'll do more investigating but thank you so much for your enlightenment. I never stop learning new things about old things....

 

[Sean in PA]

Use a good de-greaser to remove all of the oil, and then once its' clean and dry. sprinkle some baby powder all over the bottom and sides of the rear axle enter housing. Then run it and raise and lower the 3 point lift a few times. The baby powder will turn dark and clump up at the source of the leak once it starts leaking again.

 

[Joe_R]

Use a good de-greaser to remove all of the oil, and then once its' clean and dry. sprinkle some baby powder all over the bottom and sides of the rear axle enter housing. Then run it and raise and lower the 3 point lift a few times. The baby powder will turn dark and clump up at the source of the leak once it starts leaking again.

Excellent idea. I'll giv'er a try. Thanks.

 

[jrh009]

That plate covers the pressure relief valve. There is a gasket and O-rings. As has been noted, it's usually on quite tight.
View attachment 2758
View attachment 2759

What is this document, I have 2 different manauls but they do not include part numbers

 

[pomester]

What is this document, I have 2 different manauls but they do not include part numbers

 

[jrh009]

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Thank you, going shopping.