AC 8550 Transmission HELP

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   Hi there, we recently bought an 81 AC 8550 with around 7000 hours.  The tractor runs and worked perfectly for about 30 hours of field work this spring for us.  We were rolling beans yesterday and just as we kicked the foot button on the floor into high after turning a corner it started grinding very badly and the tractor stopped moving.  It makes a high grinding sound kind of like when a starter is grinding on the ring  gear but louder.  It doesn't make the sound out of gear, only when the tractor is put into gear.  I am wondering if any of our have a diagram of the parts  you feel this would be or if you have some knowledge of this and if there are weak points in these tractors.  looking in my service manual, it looks like there are some couplers in between the drop box and the transmission.  If anyone could elaborate on this I would really appreciate it. My manual is a copy and you can't see the pictures worth a hoot.  Also if anyone would have or know where parts for this would be would be great.  I thank all in advance.  Thanks

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bkrapp Members Profile Send Private Message Find Members Posts Add to Buddy List Bronze Level Joined: 10 May 2010 Points: 2	Post Options Post Reply Quote bkrapp Report Post Thanks(0) Quote Reply Topic: AC 8550 Transmission HELP Posted: 10 May 2010 at 9:56am
	Hi there, we recently bought an 81 AC 8550 with around 7000 hours. The tractor runs and worked perfectly for about 30 hours of field work this spring for us. We were rolling beans yesterday and just as we kicked the foot button on the floor into high after turning a corner it started grinding very badly and the tractor stopped moving. It makes a high grinding sound kind of like when a starter is grinding on the ring gear but louder. It doesn't make the sound out of gear, only when the tractor is put into gear. I am wondering if any of our have a diagram of the parts you feel this would be or if you have some knowledge of this and if there are weak points in these tractors. looking in my service manual, it looks like there are some couplers in between the drop box and the transmission. If anyone could elaborate on this I would really appreciate it. My manual is a copy and you can't see the pictures worth a hoot. Also if anyone would have or know where parts for this would be would be great. I thank all in advance. Thanks

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7060 Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 16 Sep 2009 Location: Missouri Points: 1148	Post Options Post Reply Quote 7060 Report Post Thanks(0) Quote Reply Posted: 10 May 2010 at 11:31am
	You can go to www.agcopartsbooks.com and look at the book online. I think the 8550 still had the same transmission as the 7000 series tractors and same drop box as 7580 but they had different gearing. Does it move in any combination of gears or ranges, maybe even in neutral. Does it want to die when the clutch is let out? How was the oil level in the transmission?

DrAllis Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 12 Sep 2009 Points: 20947	Post Options Post Reply Quote DrAllis Report Post Thanks(0) Quote Reply Posted: 10 May 2010 at 11:45am
	8550/4W305 are a totally different tranny and parts might be hard to come by. I do know they are good at drop box failures of some kind....may be the issue here/?

bkrapp Members Profile Send Private Message Find Members Posts Add to Buddy List Bronze Level Joined: 10 May 2010 Points: 2	Post Options Post Reply Quote bkrapp Report Post Thanks(0) Quote Reply Posted: 10 May 2010 at 11:50am
	No it doesn't move in any combination of gears. It doesn't wnat to die, it just grinds like something stripped out. The oil level was good. Thank you for the info and any help you can give me. Blake

DrAllis Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Access Joined: 12 Sep 2009 Points: 20947	Post Options Post Reply Quote DrAllis Report Post Thanks(0) Quote Reply Posted: 10 May 2010 at 12:03pm
	Shift the 5 speed into any gear and leave the range lever in park.....see what the sound is like then with the clutch pedal up.

Cb NwO Members Profile Send Private Message Find Members Posts Add to Buddy List Bronze Level Joined: 02 Jun 2010 Location: Bowling Green O Points: 5	Post Options Post Reply Quote Cb NwO Report Post Thanks(0) Quote Reply Posted: 03 Jun 2010 at 12:22pm
	Where did you get this 8550 from?

robo123 Members Profile Send Private Message Find Members Posts Add to Buddy List Bronze Level Joined: 03 Jun 2010 Location: Durand, Wi Points: 3	Post Options Post Reply Quote robo123 Report Post Thanks(0) Quote Reply Posted: 03 Jun 2010 at 2:18pm
	Sounds to me like maybe you striped the splines out of the middle of the Power Director clutch hub.

Matt MN Members Profile Send Private Message Find Members Posts Add to Buddy List Orange Level Joined: 14 Sep 2009 Location: Silver lake MN Points: 1491	Post Options Post Reply Quote Matt MN Report Post Thanks(0) Quote Reply Posted: 07 Jun 2010 at 11:33am
	Here is a posibility for some parts. 8550 Parts tractor
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