720d cam idler gear question

JLG

Member
The cam idler gear on my early 720 diesel is starting to eat into the main case. Took the gear off and noticed that the shaft the gear sits on is tight in the main case. The problem seems to be there is no snap ring on the outside of the idler gear bearing, allowing the gear to slide inwards on the bearing over time and eventually get close enough to rub the case. The parts book shows a snap ring on either side of the bearing, plus the little snap ring on the end of the shaft that holds the gear on. I have the inner snap ring and the little ring on the outer end of the shaft, but not the outer snap ring that holds the bearing in place, and there is not even a grove in the gear for this snap ring. The one idler gear has F1901r on it. That number isn't in my parts book, I assume it's a casting number.

Is this the idler gear set for a late 720 / 730? I see that gear looks to be held on with a bolt and washer, does it not have the outer snap ring?

The gear is in good shape. I was going to just have a snap ring groove machined in and put her back together. But there is some slop where the bearing meets the shaft, so I am going to replace the bearing and shaft. If I'm buying a new shaft anyway I'm wondering if I should just get the later 730 style shaft if I do in fact have the later style idler gears?

I guess the bottom line is - is this cam/govenor idler gear set I have from a late 720/730? If so, will the 730 style shaft fit my early 720 main case?

Thanks for any help!
 
If I understand you right, you have an early gear. The late ones start with an R. The later stud is has a larger outside diameter and will fit in the early tractors, if you drill and tap the maincase for the bolt. You will also need the late gear setup. I have reproduced the later studs and I have good used gears.
 
My email is open. Let me know how much for a new style shaft, and a good used gear.

I'm still debating whether I want to just put a new, old style shaft from Deere in, new bearing too, and cut a snap ring groove in mine. Or if I want to update it all. The stud seems to be tight in the main case now, but I want to pull it and make sure it's not oversized already. There's enough slop in the bearing to shaft joint that I want to replace the shaft and bearing. Just not sure which way to go.

Thanks!
 

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