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Thanks. I think someone had recently done an oil change on their tranny, before issues, but I don't remember if that was your discussion, or if I'm mixing them up.

What does the kit include? As you said, not cheap, but way less than a new tranny!

I've been doing a bit of reading on servicing my tranny. It's not that it's "weak", it does normal stuff just fine. But pulling an implement, the implement got stuck, and it couldn't spin the ATV tires (just got a bunch of tranny noise), which disappointed me a bit. I did then also notice some odd recent behavior with my bypass control, it didn't release fully (to make the transmission drive normally) until I cycled it maybe 5-10 times quickly. So it has me wondering if something a bit weird is going on internally.

If I take it apart this winter, areas that I will look at closely include the bypass valve, and the checkvalves. Aside from the pistons & cylinders, and the valve plate (? the flat surface with some curved slots, which mate with the cylinders), it seemed like those valves could also be a source of internal leakage, or bypass.

I saw specs in the Hydro-Gear service manual for piston diameters. I'm sure all the sliding surfaces should be smooth, and no grooves, of course. But if micrometers were available, service documentation might give you a spec for what the piston outside diameters should be. I don't think my digital calipers would be accurate enough to measure them, but micrometers should do it, if you were interested. It might at least give an indication of whether they'd be considered accceptable, to better understand the parts you're replacing.

Hopefully the machine pulls like an ox after this! And any pictures of what you find would be interesting to see.
 
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thanks for posting the pic. more would be appreciated! I'd also like to see how the diff. lock is designed so I know when engaging it how much beef is in the parts I'm loading up!
 

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Discussion Starter · #63 ·
thanks for posting the pic. more would be appreciated! I'd also like to see how the diff. lock is designed so I know when engaging it how much beef is in the parts I'm loading up!
there is a large C-shaped arm that rotates when the differential lock is engaged (first pic, kinda hard to make out, but it's the dark steel piece on the left side) to prevent the differential from being a differential lol. It fits into a slot next to the drive gear (marked in red) that when engages does not allow the differential assembly slip out and function. that steel arm and the whole mechanism is very robust looking. I'm not a mechanic but this appears how it functions.

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thanks for posting that! I see how the fork engages the clutch dog but still not real clear how much beef in the dogs that actually transfer the power! I'm always leery about hitting the lock when going up a hill with loaded cyclone rake and tire spin occurs! I prefer to keep the momentum going instead of stopping to apply the diff. lock.
I probably shouldn't worry about it because traction at that point is minimal and likely won't break anything [i hope}
 

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I probably shouldn't worry about it because traction at that point is minimal and likely won't break anything [i hope}
Hmmm, that is actually what the manual cautions against doing. You need to hit the button before one wheel spins. It is the speed difference that the diff-lock has to stop. So, going straight, with good traction, there is no speed difference, no stress on the diff-lock. Turning with good traction, one wheel is going faster than the other. Straight with poor traction, the wheel with the least traction is going faster. The diff-lock has to now bring them both to the same speed to lock them. That is some stress, but clearly less than when turning with good traction.

IMPORTANT: Avoid damage! To prevent damage to traction assist, do not engage traction assist at high speeds.

Not sure what is considered high speed for a K72.
 

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Yeah, I know Cub says not to engage the diff-lock while spinning, at least. Maybe even while moving, though I'd have to check (I don't have that feature). It sounds like engaging the lock while spinning isn't doing the tranny any favors, at least.

Stopping and losing momentum is free, a blown transmission is definitely not :) I'd rather stop and engage it. Or, maybe better yet, just engage it proactively if you risk losing traction, before anything actually spins. That may go easier on the grass too, if you avoid spinning a tire in the first place.
 

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good idea changing the filter with a rebuild! but years ago a service tech told me changing the filter as preventative maintenance is pointless, if the filter is plugged with material the trans. is already trash!
 

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good idea changing the filter with a rebuild! but years ago a service tech told me changing the filter as preventative maintenance is pointless, if the filter is plugged with material the trans. is already trash!
As a former trans tech, I concur.
 

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Discussion Starter · #70 ·
Yes the filter gets replaced. That is the brand new filter right there. The old one didn't look all that different either.
 

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Discussion Starter · #71 ·
IT'S ALIVE!!!!!!!!!! Transaxle repair complete... test run up and down the driveway confirmed no loss of power. I'm going to put the 48" deck on tonight and mow the front lawn and put it through it's paces. I can't tell you how relieved I am that it appears to be functioning correctly!!!

I also noted the steering on this machine is far more easy than the other x500 I'm in possession of, so now another thing to trouble shoot and figure out.

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Glad you got it working. So now there is documented evidence that even the K72 isn't invincible. It also shows that it is possible to rebuild it and get it back to functional. That is reassuring. Thanks for reporting back. Many people never do.
 

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Awesome! That's great, congrats!! I'm sure that's a big relief. Are these power steering, or manual?
 

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Discussion Starter · #75 ·
Glad you got it working. So now there is documented evidence that even the K72 isn't invincible. It also shows that it is possible to rebuild it and get it back to functional. That is reassuring. Thanks for reporting back. Many people never do.
I think the original trans issue was from poor maintenance on me and the previous owners, tossed in with a touch of bad parts from the OEM. but, all that said once you troubleshoot all the other issues out, $400 to repair a $2000 trans is not a bad deal in my opinion. No special tools required, just some simple hand tools only. There are some tricky parts but again I'm no mechanic and it ultimately wasn't that hard. I didn't buy the repair kit from TT (saved about $70), but it ships directly from them. I want to run it some more to make sure it's all set before I can hopefully sell it before winter. Reassuring to know that if I have issues on the other machine, it's pretty easy to fix and I won't be dependent on the dealer and their high costs to fix.
 

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I think the original trans issue was from poor maintenance on me and the previous owners, tossed in with a touch of bad parts from the OEM. but, all that said once you troubleshoot all the other issues out, $400 to repair a $2000 trans is not a bad deal in my opinion. No special tools required, just some simple hand tools only. There are some tricky parts but again I'm no mechanic and it ultimately wasn't that hard. I didn't buy the repair kit from TT (saved about $70), but it ships directly from them.
That's great! In hopes of learning a bit from your experiences, what did you find when taking it apart, and comparing the old parts to what came in the rebuild kit? And what did the rebuild kit replace?

I'm glad you were able to get it fixed, I hope it will continue to impress. That's a really nice cost savings, vs needing to replace it!
 

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Discussion Starter · #77 ·
That's great! In hopes of learning a bit from your experiences, what did you find when taking it apart, and comparing the old parts to what came in the rebuild kit? And what did the rebuild kit replace?

I'm glad you were able to get it fixed, I hope it will continue to impress. That's a really nice cost savings, vs needing to replace it!
I still have the old parts that were replaced. I'll try to get some pics. From the naked eye there is nothing glaring, but in the hydrostatic application I think .001's make a huge difference in the unit making power vs oil flowing past and not making power. as heat buildup occurs with lower oil levels there is more friction which undermines those very tight tolerances, and then it starts to fail. slowly then more pronounced. monitoring your trans fluid level and drain/refill fluids at the recommended intervals will pay huge dividends in the end. about a $500 lesson here for me. No big deal as I can now take apart a trans and put it back together in about 20-30 mins, hope i never have to again.

the leaky cap under the fan/pulley is a huge issue on older (mid 2000's to mid 2010's), it's junk, cracks easily, spews oils, and should be replaced if leaking asap, maybe even before it leaks as the new part is more robust and should last a lifetime. it costs $6 to replace.
 

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only john deere could make a higher model number with less options! x570 no p.s./air cooled. 540 has p,s. and lift and liquid.
I'll be waiting to see the inside of an 72B next and see how that auxilliary pump works, my wife uses the 500 at home and ps would be nice for her. i drive the 540 but i cut about 15 times as much grass a week at the club.
 

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Discussion Starter · #79 ·
only john deere could make a higher model number with less options! x570 no p.s./air cooled. 540 has p,s. and lift and liquid.
I'll be waiting to see the inside of an 72B next and see how that auxilliary pump works, my wife uses the 500 at home and ps would be nice for her. i drive the 540 but i cut about 15 times as much grass a week at the club.
On the 2009 x500 I have the manual steering is pretty easy to be honest, the 2014 I have it's noticeably more difficult, but not horrible either. I'm sure PS would be nice. My next tractor is going to have it without question, hopefully it's a x7
 
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