Increase Top Speed On Your Gravely ZTHD Zero Turn

Is your zero turn mower slower than advertised? This little trick will help you increase the speed on your Gravely ZTHD or other zero turn mowers, and help you make sure it's going straight when you're going full speed.

[@TorqueWagon]

I learned about this adjustment from a viewer, but it’s in the owner’s manual too. What other tricks do you have for mower maintenance and adjustment before your first mow?

[@salhrtman6822]

Thanks for the info very helpful didn't Know I could adjust the speed, just purchased a 2021 52 ZTHD last weekend and used it yesterday for the first Time I did feel I was mowing kinda slow compared to my other zero turns

[@kevinspahr6632]

It would be much better if you used an Allen wrench and an open end wrench😁

[@PegasusIV]

easier to use the closed side of a box wrench if there’s room. You can also just measure the height of the screw and make both sides match.

[@kevinspahr6632]

Or look at the handle controls and adjust accordingly 😊

[@precisioncutsandtrimslawns6645]

I really appreciate that, I have the same exact mower

[@shawncox485]

This is awesome. Thank you so much!!

[@scottnunya2441]

If you do adjust them, I recommend finding the same starting point (backed all the way out or screwed all the way in) then counting turns, or removing completely, counting threads, and marking the same point. You'll likely need to fine tune them after the first adjustment. For owners of other type Gravely's, you may find this adjustment bolt is horizontal to the bars, facing directly forward in the open, and much easier to access. I have a Pro 160 and the adjustment bolts arrived with them nearly bottomed out already, and it moves pretty quick so no need for me to mess with them.

[@salvadorarreola4729]

mine is a 2020 zt hd 52 but since I remove the screws, the tractor still mowing at 5 to 6 MPH

[@vityaak6898]

is there a way to adjust reverse speed? mine doesn't go in reverse straight

[@robertgraydon4195]

What state do you live in? Looks like a nice area.

[@TorqueWagon]

Thanks. I live in Southern Indiana. It is especially nice in the fall, and the winters aren’t bad either.

[@robertgraydon4195]

@@TorqueWagon Nice! I've never seen that part of the country but I have a couple friends who are from Indiana. I'm in Central Oregon. Lot of rocks. Rough on mowers.

[@rickyrobinson4573]

What's your final setting 3 full turns?

[@SunriseCrawlers]

Another thing you could look into is putting a thicker fluid in the pumps. They are hydraulic motors so in theory a thicker fluid would cause less loss

[@scotthildebrand1904]

What oil weight do you use? And Brand name

[@lissettelopez8331]

For this mower it’s 2qt 10w30 synthetic.

[@paisteplayer1040]

My Gravely pro turn 60 does 8-9mph...

[@greggreen6636]

Top speed supposed be 8 anyway

[@thebertusmcth]

Why not just pull the bolt completely off to get full range of motion?

[@TorqueWagon]

I may have to try that. The way my luck goes, the thing wouldn’t track straight with the bolts completely out of both sides.

[@thebertusmcth]

@TorqueWagon if it tracks to one side slightly just put the bolt back in on the opposite side its tracking to. And just barrrreeeelllyyyy limit the range of motion on that arm. Voila. Should go straight. But atleast then you would know you are getting full speed out of it.

[@TorqueWagon]

Good point. I think the tire pressure can have some effect on the tracking as well, so it’s important to make sure the tires equal pressure.

[@N-1951]

All that just adjusts the steering lever position to keep them even. It doesn’t increase the speed.