Blowing out transmission filter gasket

[rfwineguy]

Greetings, I have had a 1963 Ford 3000 selecto shift tractor for about 15 years. Last March when grading our farm lane the transmission filter gasket blew out. Assuming an old gasket with loose bolts, I replaced the gasket, filter and torqued properly. Upon start up, same thing, blown gasket. I towed it to our shop, and with the service manual as a guide, removed the transmission cover, upper trans manifold, and checked the alignment of the selector shaft. I disassembled and cleaned the manifold and I also checked the main pressure tube from the filter to the manifold. Same issue, the filter gasket keeps blowing. Apparently there is a blockage somewhere not mentioned in the service manual. Any ideas out there???

 

[Bern]

If your SOS filter uses a gasket, then your tractor is a 1965 or newer. If the gasket blows, either the pressure is too high or else the cover is warped. A pressure test will quickly tell you if the pressure is too high.

 

[rfwineguy]

Thanks for your assist. The cover plate is cast iron and flat. I'll do a pressure check. but suspect a blockage in the lower manifold. Does the lower manifold come out or just the upper half? The service manual only describes the upper half.

 

[Bern]

Thanks for your assist. The cover plate is cast iron and flat. I'll do a pressure check. but suspect a blockage in the lower manifold. Does the lower manifold come out or just the upper half? The service manual only describes the upper half.

When you say "upper and lower manifold", I assume you're talking about the control valve? If so, then yes, both pieces come off of the distributor. But do a pressure test first. I would also find a copy of a repair manual if you don't already have one to make sure that, at a minimum, you get your cable adjustments correct. Said manual will also show you fluid flows so you can pinpoint the possible point of obstruction, should a pressure test reveal high pressure.

 

[rfwineguy]

Got it. I'm in the process of setting up the pressure test. I have the repair manual. However, I don't believe I can run a pressure test without blowing the gasket (for the third time). The cable adjustments are fine. I set the control valve in Park with the cam closing the starter safety switch. Is there a way to check the distributor for blockage with the control valve off other than compressed air? I've disassembled the control valve, cleaned and reassembled. I did not find any obstructions. What would be the best way to clear the main pressure tube from the filter to the control valve if that is the problem. I can get air through the tube but I'm not confidant it's 100% clear.

 

[Bern]

Got it. I'm in the process of setting up the pressure test. I have the repair manual. However, I don't believe I can run a pressure test without blowing the gasket (for the third time). The cable adjustments are fine. I set the control valve in Park with the cam closing the starter safety switch. Is there a way to check the distributor for blockage with the control valve off other than compressed air? I've disassembled the control valve, cleaned and reassembled. I did not find any obstructions. What would be the best way to clear the main pressure tube from the filter to the control valve if that is the problem. I can get air through the tube but I'm not confidant it's 100% clear.

You should be able to take the control valve off and blow air backwards in the main supply tube and into the filter housing. I'd be shocked however, if that tube was actually plugged.

 

[rfwineguy]

Yup, did that. Even ran a flexible cable through. Tube seems ok. The control valve has a 7/16 hex bolt on the underside. The repair manual states in bold type not to remove "two" bolts from the control valve without describing a location. There are 7 bolts on the top to remove from the distributor and one underneath. I assume the underside bolt fastens the two halves of the valve. I suppose I should check this out for an obstruction inside the valve. I'm thinking a piece of the old filter dislodged and traveled into the system. This all started quite suddenly without any warning, noise, etc. Tractor running fine, then bam, oil all over.