ZF Gear: No Oil Pressure

[Dan Mapes]

Does not go into gear. Zero oil pressure.

Wow. That certainly says something if the other gears can shift. The Capitol gears we had did not have a filter. Just a screen inside the pan on the hose going up to the pump. The pump was external and all of the hoses etc. were as well.
If you have access to any of the oil lines to/from the pump I'd pull them, inspect them, and crank for a second or two and see what happens. Be ready for a spray and make sure the engines don't start.
When I pulled the gears out of ours all I did was fill it up again and the pump took care of the rest.

[dsharp]

Missed the post about the second oil pump. That would be the easiest way to prime the system. I’d be interested in seeing a picture of that setup.

[racclarkson@gmail.com]

I’m not familiar with Covington’s or ZF gears. Do they have gear coolers on the front of the engine? Breaking the vacuume to the gauge may have let all the oil drain back to the sump. I’m betting that the pump lost it’s prime. Can you get oil to the pump from the cooler lines?

Thanks. The pump is driven by the transmission. I intend to get underway on good engine and freewheel shaft to ensure prime via the prop shaft driven pump. The oil system is common, so either pump will fully prime. But it's looking more and more like I'll need a pump or a pump rebuild.

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[Dan Mapes]

I'm wondering if you had a pressure blip that blew out the hose. Is there a regulator you can unscrew and have a look at?

Our gears came out because the clutches were dumping debris. They jammed the regulator and fortunately I caught it before things went really south. As it turns out the oil cooler was plumbed in AFTER the regulator and it was dropping the pressure significantly. While the regulator maintained the pressure correctly, the tranny never saw it. They had to spray weld/machine the input shaft to build it up again and install new clutches.

[Avenger]

Is the engine driven pump external? Might be time to split it open and see what is going on. Or before that maybe you could pull a connector off and look to see if the gears are visible. Look while someone is cranking the engine to see if they are turning.

[racclarkson@gmail.com]

I’m not familiar with Covington’s or ZF gears. Do they have gear coolers on the front of the engine? Breaking the vacuume to the gauge may have let all the oil drain back to the sump. I’m betting that the pump lost it’s prime. Can you get oil to the pump from the cooler lines?

I'm wondering if you had a pressure blip that blew out the hose. Is there a regulator you can unscrew and have a look at?Our gears came out because the clutches were dumping debris. They jammed the regulator and fortunately I caught it before things went really south. As it turns out the oil cooler was plumbed in AFTER the regulator and it was dropping the pressure significantly. While the regulator maintained the pressure correctly, the tranny never saw it. They had to spray weld/machine the input shaft to build it up again and install new clutches.

Possible on hose blowout, but unlikely. It’s pretty old and brittle and blew at the swage where the line was easy to disturb over the years.

[racclarkson@gmail.com]

I'm wondering if you had a pressure blip that blew out the hose. Is there a regulator you can unscrew and have a look at?

Has regulator, but not the issue. It won’t even fill up the filter chamber. Regulator is downstream.

[racclarkson@gmail.com]

Is the engine driven pump external? Might be time to split it open and see what is going on. Or before that maybe you could pull a connector off and look to see if the gears are visible. Look while someone is cranking the engine to see if they are turning.

Planning on that after I see if the prop shaft pump pressurizes. That should take care of any issues like pressure regulator or stoppage in the plumbing. I am trying to find out what I’m dealing with before potentially creating new variables. I’m not smart enough anymore.

[racclarkson@gmail.com]

Missed the post about the second oil pump. That would be the easiest way to prime the system. I’d be interested in seeing a picture of that setup.

Here you go.

[krush]

You have manual with the fluid flow diagram? Post it