7040 Power Director

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   Good afternoon. I have a 7040 apart for a slipping low side. Best I can figure, I was losing pressure through old hard seals, and piston return bolt (sleeve) holes. The inner seal was partially hidden behind the piston lip, which likely would have added to the problem. I have a black belly book, and it mentions a running update to the pistons where the inner seal sits. I also see mention of different low side pistons between a 7020 and 7045, mainly to account for an extra separator and friction disc. Can I have the piston machined down to allow room for an extra steel and friction disc, or are the housings different. Looking through the parts diagram, I highly suspect it would work, but I wanted to check with the knowledgeable folks on here.  

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joe Members Profile Send Private Message Find Members Posts Add to Buddy List Bronze Level Joined: 30 Nov 2009 Location: SW Ontario Points: 146	Post Options Post Reply Quote joe Report Post Thanks(0) Quote Reply Topic: 7040 Power Director Posted: 12 Feb 2025 at 12:30pm
	Good afternoon. I have a 7040 apart for a slipping low side. Best I can figure, I was losing pressure through old hard seals, and piston return bolt (sleeve) holes. The inner seal was partially hidden behind the piston lip, which likely would have added to the problem. I have a black belly book, and it mentions a running update to the pistons where the inner seal sits. I also see mention of different low side pistons between a 7020 and 7045, mainly to account for an extra separator and friction disc. Can I have the piston machined down to allow room for an extra steel and friction disc, or are the housings different. Looking through the parts diagram, I highly suspect it would work, but I wanted to check with the knowledgeable folks on here.

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DrAllis Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 12 Sep 2009 Points: 21392	Post Options Post Reply Quote DrAllis Report Post Thanks(0) Quote Reply Posted: 12 Feb 2025 at 2:09pm
	Since 1976, I've been drilling six 3/32" small holes from the inner seal lip area thru the oil side of the piston. This allows the oil to flood the seals lip and work much better. A-C machined a chamfer on the piston groove oil side to accomplish the same thing. I think you can add a 4th disc to low range by changing the piston thickness if there's enough room for the separator plate to retract that far to allow one more disc and plate.

Lynn Marshall Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 13 Sep 2009 Location: Dana, Iowa Points: 2343	Post Options Post Reply Quote Lynn Marshall Report Post Thanks(0) Quote Reply Posted: 12 Feb 2025 at 4:53pm
	I have had a local guy chamfer the pistons, with his lathe, several times. I also had at least one of the thick pistons milled down to the thin dimension and then added another friction and separator plate. Works fine. Edited by Lynn Marshall - 12 Feb 2025 at 8:08pm

tbran Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 14 Sep 2009 Location: Paris Tn Points: 3482	Post Options Post Reply Quote tbran Report Post Thanks(0) Quote Reply Posted: 12 Feb 2025 at 5:20pm
	Yes the housing is the same as the ones for the extra plate - will have to measure the plates - separator and clutch - and take that much off the piston. 70268367 is the plate the separator is 70268794 and the wave spring is 70267408. The seal kit is 70272374 and it will sub.
	When told "it's not the money,it's the principle", remember, it's always the money..

tbran Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 14 Sep 2009 Location: Paris Tn Points: 3482	Post Options Post Reply Quote tbran Report Post Thanks(0) Quote Reply Posted: 12 Feb 2025 at 5:31pm
	Will try to get a print thickness off of piston if it exists.
	When told "it's not the money,it's the principle", remember, it's always the money..

joe Members Profile Send Private Message Find Members Posts Add to Buddy List Bronze Level Joined: 30 Nov 2009 Location: SW Ontario Points: 146	Post Options Post Reply Quote joe Report Post Thanks(0) Quote Reply Posted: 13 Feb 2025 at 11:43am
	As I've continued to look into parts, etc, I came across talk of the scavenger pump. This tractor still has a pump, and I'm seeing talk of updating it to a gravity return system. What is involved in this? I assume a new cover, but there must be more than that. Edited by joe - 13 Feb 2025 at 11:48am

DrAllis Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 12 Sep 2009 Points: 21392	Post Options Post Reply Quote DrAllis Report Post Thanks(0) Quote Reply Posted: 13 Feb 2025 at 5:34pm
	I think I have changed over every tractor we ever sold as time went on. This avoids the possibility of the scavenge pump failing and damaging the lower countershaft gear. It also sees to it the gerotor pump never starves for oil when the nose of the tractor is pointed down a very steep hill. Any black chassis tractor with the 16 or 20-speed Powe r Director trans has all the parts. Later models maroon chassis have it too.