Flush Transmission

[DozerArk7]

I purchased a 1987 JD 450e several years ago and just started to use it recently. I’m a firm believer in preventive maintenance so purchased the tech manuals also. After reading the posts I found that several have similar problems to what I have with the transmission. I have many questions but would first like to start with flushing the transmission fluid from the system. The fluid is milky and when I pulled transmission filter screen it had a lot of junk in it and the canister, hopefully none of it was clutch. The wire was connected to the cap but was broken off 6 inches from the cap. The seals and gasket were in bad shape with pieces missing so I ordered new. My question here is whether the entire system can be flushed and if it can be done how is the best way to do it. I found nothing in the manual for this. It makes no sense to me to replace the fluid, hydraulic filter and install it and the screen if they just plug up again.

[Lavoy]

I would guess you can somewhat flush the crud out of the bottom of the case by dumping diesel or kerosene, but not sure if you dare run it to "flush" it through the system.
Milky is water, so after you decide what to t do, and get fresh oil in it, I would dump in a can or two of Seafoam, and work it til you have the the trans warm for at least half an hour, that should evaporate any remaining moisture.
Lavoy

[Mikeforester]

Hi,
No way to really flush this out. We had a similar situation and drained the fluid, cleaned the transmission screen, and refilled with fresh fluid. (Change steering clutch oil as well as the clutches share sump oil with the trans.) When we went to restart the tractor we disconnected the return line to the transmission at the oil cooler and attached a hose to drain into a bucket. We started the tractor and ran it for a few seconds to let the transmission pump flush out the cooler circuit (it went from milky to clean pretty quick). We probably pumped 2 gallons out of the transmission, but we're able to clean out contaiminated oil in the cooler circuit which would have quickly ruined the new oil. Then we reconnected the return line, put on a new filter, topped off the trans and ran the machine for a few hours on light duty just to get everything warm. We drained the oil overnight just to get as much oil out as we could (clutches too). Refilled with new oil, another new trans filter, and two bottles of Sea Foam. It's been 3 years and the oil is still like new. Water contamination is tough and takes time to clean out of the system. Hope this helps.
Mike