Welcome to the ZK MasterTech! See what it's like to dive into the world of a Master John Deere Ag Technician, Zeth Key. A 2007 Automotive Graduate of Wyotech in Laramie, WY and 2023 WyoTech Hall of Fame Inductee now finds himself working on John Deere diesel tractors and combines in the farm lands of central Illinois.
Working for Sloan Implement in Atwood, IL for over a decade, Zeth has seen just about every failure your John Deere equipment can have. Subscribe to ZK MasterTech to see what it's like to repair some of the most advanced farm machinery you can buy!
Being a John Deere technician is one of the most rewarding and challenging careers you can get into. Just like the whole industry, companies in AG have a hard time finding talented, experienced people. Hopefully this channel will show the world the technical side of agriculture and what it takes to keep the farmers going and to inspire a younger generation to pick up a wrench a start a great career with Sloan Implement!
ZK MasterTech
The rear differential is FINALLY out of the 9RX 640.
What we found on the pinion gear is something none of us expected.
Full video is live now:
https://youtu.be/WQsdG1iU6SY
4 days ago | [YT] | 563
View 10 replies
ZK MasterTech
The next chapter of the 9RX 640 teardown is finally here.
After discovering the failed pump stack that caused the rear axle to lose lubrication pressure, we had to tear half the tractor apart just to get to the rear differential.
Fuel tank, track belts, track frames, final drives, PTO, hitch frame… everything had to come off.
Today at 3 PM you’ll finally see the moment the rear differential comes out — and the damage to the pinion gear is something I’ve never seen before.
This one is wild.
See you at 3 PM. 👀
And as always — keep that green iron moving! 💚🔧
5 days ago | [YT] | 805
View 32 replies
ZK MasterTech
Today’s video is not a routine repair.
This machine came in with zero lube pressure — and what we found inside explains everything.
We’re talking:
• Major drivetrain damage
• Metal where metal should NEVER be
• Cab coming off
• Pump stack removal
• Digging deeper after the first failure revealed even more
This one snowballed fast… and the teardown only gets worse the farther we go.
If you like real diagnostics, real damage, and real decisions that cost real money — this is the episode.
Drops at 3PM.
1 week ago | [YT] | 762
View 24 replies
ZK MasterTech
Just got back from the National Farm Machinery Show 2026 in Louisville and it was awesome meeting so many of you at the Sloan Express booth. Thank you to everyone who stopped by the Meet & Greet — truly appreciate the support.
Once back in the shop, I tackled a catastrophic discharge beater bearing failure on a John Deere S790 combine that melted wiring and took out both bearings.
Then the big project finally arrived.
The 9RX 640 is now in the shop with no rear track drive, zero axle lube pressure, and completely destroyed pinion gears. I walk through the full diagnosis and explain what caused the failure and what it will take to repair it.
This is just the beginning of this major repair series.
Watch the full video here → https://youtu.be/wKKLABIGUmM
2 weeks ago | [YT] | 396
View 5 replies
ZK MasterTech
New video going live today at 3:00 PM.
Last harvest season this S780 came to a stop in the field with low transmission pressure. Field diagnostics led us to the 5 speed feeder house gear case… and once it came apart, the damage told the whole story.
Big teardown, major failure, and a full repair from start to finish. If you like seeing what actually fails inside these machines, you’ll want to see this one.
See you in the comments at 3.
— ZK
4 weeks ago | [YT] | 366
View 1 reply
ZK MasterTech
I’ll be at the National Farm Machinery Show in Louisville, Kentucky Saturday, February 14th!
If you’re coming to the show, stop by and say hi — I’ll be hanging out with the Sloan Express crew at Booth #8943. Always good putting faces to names and meeting the people who watch the videos and keep this industry moving.
We’ll talk diagnostics, repairs, equipment, content, or whatever green iron problems you’re fighting this season. I’ll have some merch with me too while supplies last.
Looking forward to meeting you guys in person. See you Saturday 👊
#ZKMasterTech #NationalFarmMachineryShow #FarmMachineryShow #LouisvilleKY #JohnDeere #AgMechanic #DieselTech #FarmLife #AgTech #SloanExpress #KeepThatGreenIronMoving
4 weeks ago | [YT] | 242
View 0 replies
ZK MasterTech
It’s finally time.
The last chapter of the John Deere 9520 engine saga goes live today.
After everything this tractor went through, it all comes down to one moment and one turn of the key.
If you’ve followed this series from the start, thank you — this one’s for you.
If you’re just finding it now, buckle up… nothing about this was guaranteed.
Video drops at 3:00 PM.
See you in the comments.
Which video did you like the best so far in the 9520 engine series?
— ZK
4 weeks ago | [YT] | 139
View 8 replies
ZK MasterTech
NEW TIKTOK ACCOUNT!
www.tiktok.com/@thezkmastech?is_from_webapp=1&send…
Just an FYI I had to get a new TikTok account because the overlords and bots from China decided to accidentally permanently ban my entire TikTok account when I was filing copyright infringement reports against fake accounts. So, I appealed to no success, they didn't even respond. I made a new account and I will be posting content to that account. Please give this account some followers!
www.tiktok.com/@thezkmastech?is_from_webapp=1&send…
4 weeks ago | [YT] | 71
View 10 replies
ZK MasterTech
REMINDER!
New video drops today at 2:30 pm!
In case you missed the previous videos to catch the whole story in depth, I put all the videos on the 9520 engine in a playlist here- www.youtube.com/playlist?list...
4 weeks ago | [YT] | 60
View 0 replies
ZK MasterTech
🚨 New video drops TODAY at 2:30 PM 🚨
This one’s a big one.
I take you through the complete 12.5L long-block build on a John Deere 9520, start to finish. What began as a catastrophic engine failure caused by coolant intrusion from a failed water pump turned into a full complete block assembly build on the stand — and I show everything.
Injectors, valvetrain setup, timing, seals, turbo, fuel system, oil system, and final prep before install. No shortcuts, no guessing, just real-world shop work done the right way.
If you like long, in-depth builds and want a true look at how big iron gets saved, make sure you’re here for this one.
⏰ 2:30 PM today
4 weeks ago | [YT] | 446
View 3 replies
Load more