7040 power director
Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=204604
Printed Date: 18 Dec 2024 at 3:50am
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com
Topic: 7040 power director
Posted By: HagerAC
Subject: 7040 power director
Date Posted: 17 Dec 2024 at 2:49pm
I posted this on facebook yesterday but thought I'd post it here as well. I have a customers 7040 with a 4 post ROPS on it that I fixed the internals on the range shift and a bunch of other work the past couple months. I thought I had it pretty well wrapped up but I noticed driving it that when I take off especially in a higher gear that the power director will slip a little bit and then will grab decent and won't slip. Checked pressure and its good, on the lower side but 190-195. Only slips on the low side, if you shift to high while its slipping in low it grabs good and will kill the engine. I have the valve off now and haven't found anything out of sorts there like i had hoped for. I'm guessing the pd needs resealed. Wondering if there is anything worth trying to try to get it working without splitting it down. He's spent more than he anticipated already on a tractor that he should have left where he found it. The oil in the transmission had a lot of water in it, and I did change all the fluids in the tractor, but it's still pretty milky and will need changed again. Someone mentioned that I should try running ATF in the tranny and maybe it would soften up the seals? Also would it be worth trying to bump the pressure up a little bit. Do I add shims in the relief valve in the pd valve or down by the gerotor pump? If it slipped constantly I would no doubt take it apart, but thought maybe we could try something to try to get it working like it should again since it only slips momentarily.
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30+ A-Cs ranging from a 1928 20-35, to a 1984 8070FWA, Gleaner R52
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Replies:
Posted By: DrAllis
Date Posted: 17 Dec 2024 at 3:19pm
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Seals on the low range clutch piston are probably as hard as a rock. ATF ?? a waste of time. You could try some automatic transmission magic elixer for a car. It would take about three cans as your compartment is 7 1/2 gallons. And, you would need to operate the tractor at near full throttle in LOW range for quite some time to get the seals to react to the magic elixer. The transmission is FULL of oil sitting on the level, right ???
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Posted By: HagerAC
Date Posted: 17 Dec 2024 at 3:54pm
Yes it is full, but still a bit milky. He decided to put a cheaper oil in it for now because he figured we'd have to change it again.
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30+ A-Cs ranging from a 1928 20-35, to a 1984 8070FWA, Gleaner R52
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Posted By: Lynn Marshall
Date Posted: 17 Dec 2024 at 10:13pm
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The transmission oil pressure light is a useful tool in checking for a slipping power director clutch. with the tractor up to operating temperature, the red light should be on at lower RPMs. As you increase the RPMs, the light should go out. It should go out at the same RPMs , whether you are in the low or high side of the PD. If it takes more RPMs in the low side to go out, then the seals are likely leaking in that side of the clutch. You can also put the tractor in low range,4th or 5th gear, and apply the brakes to see if it slips in one or both sides of the PD. If it slips severely, the red light will be on and if you lose power steering at the same time, then the torque limiter is slipping. Sometimes a good old fashioned slipping of the torque limiter will make it burn off any oil that might be on it and make it reseat itself. That may cure it for awhile, but will likely start slipping again. Everything in that area needs to be leak free. Regardless, it requires a split to fix it right and I would be looking at both the torque limiter and the power director clutch assembly while in there. On a rare instance, the clutch cable could be so stiff that its not letting the pedal and corresponding hydraulic spool return to full pressure in the up position.
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