Bushhog crazy wheel frame bent. Help

[Green Acres Homestead]

New to bush cutting. Bought a new mk martin bushhog. Works great but as I went forward to reverse I watch the wheel swivel and I thought that the crazy wheel frame is going to bend. I tried picking up the bushhog when changing direction but I forgot sometimes. It bent. I’m pounding it back straight.

Anyway I’m thinking of reinforcing it so it doesn’t bend but I’m thinking I may weld something so the wheel does swilvel 360 degrees. When I’m backing up I’ll just keep the wheel off the ground. Do you think this will work? When you change direction do you let the grass eventually swivel the wheel then drop it to the ground or do you just let the wheel stay on the ground and let the wheel swivel happen at full weight and pressure?

 

[japody]

New to bush cutting. Bought a new mk martin bushhog. Works great but as I went forward to reverse I watch the wheel swivel and I thought that the crazy wheel frame is going to bend. I tried picking up the bushhog when changing direction but I forgot sometimes. It bent. I’m pounding it back straight.

Anyway I’m thinking of reinforcing it so it doesn’t bend but I’m thinking I may weld something so the wheel does swilvel 360 degrees. When I’m backing up I’ll just keep the wheel off the ground. Do you think this will work? When you change direction do you let the grass eventually swivel the wheel then drop it to the ground or do you just let the wheel stay on the ground and let the wheel swivel happen at full weight and pressure?View attachment 978787

I never lift the BH when backing up. The wheel should swivel as you turn. When backing up, it should flip around 180'. Have you greased the grease fitting to make sure it swivels easily?

 

[WranglerX]

I find it odd the tail wheel does not swivel 360°.... And rubberized canvas curtain looks kind of cheesie....

Personally I don't think it is designed very well, seems to be manufactured very cheaply.....

 

[jyoutz]

I never lift the BH when backing up. The wheel should swivel as you turn. When backing up, it should flip around 180'. Have you greased the grease fitting to make sure it swivels easily?

Agree. I seldom lift the cutter when I’m reversing and often mow in reverse when necessary in tight spots. As you said, keeping the rear wheel spindle greased is important. Also, not hanging it up on immobile objects such as stumps. (Ask me how I know,) I just had to repair my tail wheel mount and swivel myself when I hung it on a stump and tried to power my way through.

 

[BackRoad]

1. Are you greasing the zerk on the spindle every 8 to 10 hours of use?

2. Does the wheel assembly (vertical shaft) rotate easily with a full 360 degrees when the mower is lifted?

3. Looking at the photo specifically at the top of the wheel: it looks like the wheel assembly is bent slightly, so the wheel camber is not vertical top to bottom.

It appears to be a larger gap on the top left side vs. the top right side. It's possible the wheel may not be running 100% straight up and down. Not sure this would contribute to the problem...just flagging a possible contributor...or it may just be the photo angle skewing the view.

4. I'm trying to get my head wrapped around the overall design. It appears that adjusting the angle of the strut holding the wheel assembly is used to set mowing height(?).

Thinking out loud...(which is dangerous)...if the strut was parallel with the ground, the wheel assembly should be able to rotate 360 degrees on it's axis without any significant change in force required.

The more angled the strut is, the more force would be required for the wheel assembly to rotate away from running in the straight forward position. Reverse position would actually require additional force, sufficient to lift the deck higher as the wheel assembly rotated into the full reverse position.

As a test, you might try to simply adjust the strut to be parallel with the ground and the deck. Then drive the tractor forward, try turning and reversing to see if the wheel assembly rotates 360 degrees freely with no issues as you would normally expect.

 

[Sawyer Rob]

Now you know why I NEVER buy that cheapo stuff, it's just not worth it.

Go look at how a decent rotary cutter is made and see how you can change yours to make it stronger.

BTW, Bush Hog is a brand of equipment of which they also make "rotary cutters".

SR

 

[John0829]

As long as the wheel can spin and the wheel assembly can rotate 360 I would not worry about, grease it every time you use the cutter and just keep on mowing. Tail wheels are not precision I have seen a lot of cutters with tail wheels that are not perfectly in line with the pivot point. That lightweight tail wheel assembly is just poorly made from weak/thin metal

 

[2manyrocks]

Many of the tailwheel assemblies I've seen are attached by triangulated frames to resist bending (white arrows).

Also, is your pivot tube entirely vertical or is it set an angle?

 

[mjw357]

New to bush cutting. Bought a new mk martin bushhog. Works great but as I went forward to reverse I watch the wheel swivel and I thought that the crazy wheel frame is going to bend.

Do you have a side view photo of the rear wheel assembly? It looks like it does not have any caster built into it.

 

[oosik]

Many of the tailwheel assemblies I've seen are attached by triangulated frames to resist bending (white arrows).

Also, is your pivot tube entirely vertical or is it set an angle?

View attachment 978886

Thank you - 2manyrocks. I've been looking at getting a rotary cutter. If I do - it will probably be a Rhino TW35. This one has the triangulated rear wheel assembly. I kind of thought this was for added structural strength.

Still have to avoid immovable objects.

 

[masseyrider]

I never lift the BH when backing up. The wheel should swivel as you turn. When backing up, it should flip around 180'. Have you greased the grease fitting to make sure it swivels easily?

My mower, a Bush-hog is a semi-mount with 2 tail wheels. I don't have the option of lifting it. I've had it aboot 20 years. Other than greasing the tail wheel shafts and wheel bearings I've never had an issue.
Yours may be cheap build/poor design.
I've never heard of a MK Martin.

 

[Midniteoyl]

The tailwheel looks to have a more extreme rake to it than I'm used to seeing.

 

[Mtsoxfan]

I received a NorTrac brush hog mower with used tractor. I really bent the main post and the frame. I have looked at a replacement, but can't find one that fits, anywhere. Main issue is the post length.
Sending off to a body man with right tools to try to salvage it. Bending an 1 1/4" post back into place won't be such an easy task, considering the design of fork.

 

[oosik]

I have one major problem to overcome - if I buy a rotary cutter. For 40+ years I been clearing my fields/meadows of large rocks.

Two guesses where I put them. AH - in the brush at the edge of the fields/meadows. This is the brush I want to chop down with a new cutter.

The real concern - do I want to spend the time moving all these rocks again. OR - just be happy with things the way they are.

 

[ericm979]

Lift the cutter with the tractor and check that the wheel can rotate 360 degrees. Usually there's a visible gap on the shaft above the wheel between the tube the shaft rides in and the retainer on the top. From the pic it looks like the retainer on the top is right down on the tube. If that's true it may be why the wheel is not swiveling when you back up.

The bent wheel bracket shouldn't affect that but once you figure out the problem it's probably worth bending it back into shape.

My Kodiak rotary cutter has a similar single square tube supporting the tail wheel. It's really sturdy and I back it into trees and bushes all the time. You change the wheel height by removing one bolt and letting it pivot up or down, then inserting the bolt at the new position.

 

[Mtsoxfan]

In my case, it spins freely, I must have been backing up and hit an immovable object, then kept trying to back up. Not fast, just applied the "gas".
The post is out of whack in two directions, not by much, but with as thick the post is, it might as well be. Frame is similar to OP.

 

[chim]

Looks like the yoke is just a narrow flat strap in the picture. Not a very robust piece of that's the case.

 

[ArchonOSX]

I agree, the design looks weak at the top. The legs of the wheel Fram are too long without any support to prevent racking.
I would weld a piece of 1/4" flat steel across the top front of the wheel frame to act as a gusset for both of the vertical wheel mounts.
Make it as wide as you can and still have clearance for the wheel.
It should never bend like that again.
If you want to really overkill it then weld a gusset on both the front and the back of the wheel frame.
Happy Day!

 

[Cycledude]

I usually raise the mower before backing up especially if I’m worried about hitting something that could cause trouble. Mine is a Woods Dixie cutter and it appears to be much more heavy duty than the MK Martin that started this post. Bought mine new about 40 years ago and haven’t really ever had any trouble with it, cost about $800 . Mine has a slip clutch and I don’t think there are any shear pins at least if it does have shear pins I have never had to replace one, my gearbox also appears to be built much more heavy duty.

 

[masseyrider]

Mine has a slip clutch and I don’t think there are any shear pins at least if it does have shear pins I have never had to replace one, my gearbox also appears to be built much more heavy duty.

If you had shear pins you would know it. When I had one with shear pins I could hardly finish my field talk about 40 years of cutting.