Why am I destroying tail wheel forks?????

CMV · May 17, 2021

OK.....I'm doing something wrong.....way wrong.....and about to install my 3rd tail wheel fork on a 6' Bush Hog BH6 that's almost 3 yrs old. I figured the first one was due to the hydraulic top link failing, leaking down before I noticed, and i was just loading it up too much. But most of last season, I used the standard top link and this failure/damage happened after switching so that's not issue.

As far as I know, I'm not turning and smacking it into a tree, fencepost, some hard object. I have some hills, dips, ruts, and will occasionally dig a front corner into the dirt, but nothing so bad it should be loading up the tail wheel, but all I can think is a small ditch-like area I go over must do it.

I set to cut pretty short - about as high as a typical homeowner riding mower would cut at it's highest setting - 4.5" maybe?. At least i think that's short for a bush hog. On flat level ground the front of the frame (closest to PTO) is about 3" high. I adjust toplink so the back end (tailwheel end) is about 5-6" high. I think I'm doing that right - the rear slightly higher than the front. So maybe I'm overall just too low (I want about a finish mower height, but need something that can stand up to the occasional baseball-sized rock my land likes to just magically sprout). Maybe I need more of an angle and should have the back end more than just a couple inches higher? Not sure....I thought it was just supposed to be a couple inches higher to make it want to discharge rearward vs any random direction.

Anyway for standard cutting on fairly even ground the tailwheel doesn't touch the ground. Only inclines, ruts, hills, etc. I never really notice it loading up on the tailwheel, just that sometimes it does what it should and keeps the back end from dragging on uneven ground.

Nacademus · May 17, 2021

I always have my tail wheel touching the ground.

Do you notice any situations where your tail wheel is maybe at a 90 degree to the ground and when it contacts, it's forced to whip back in line with the tractor? That's all I can think of.

mcfarmall · May 17, 2021

Hmmmm. Interesting question. Maybe it's BECAUSE the tailwheel isn't touching the ground all the time. I have a 30+ year old King Kutter on its original tailwheel, fork bearings, etc. and it gets about 60 hours a year of mowing and rough treatment. Tailwheel firmly planted on the ground the whole time.

bearthebruce · May 17, 2021

I set our tail wheel to be on the ground. Set the front to 3" clearance under the guide shoe, the rear to 4". Never run it with the wheel off the ground.. cut 15 acres 2x per summer. Bush Hog is 3 seasons old... going into its 4th with no visible wear on the wheel.

Is the wheel pivot greased and free to spin?

Is the wheel greased and free to spin?

Can't think what else would tear up the wheel.

WranglerX · May 17, 2021

Maybe if you figure it out, you have solved the issue with the wobbly wheel on the shopping cart and need to tell the grocery industry how to fix their carts...

I actually though the tail wheel was a portion of height adjustment so you did not scalp the area being cut... Do you have rigid top link where mower is not allowed to flex as mower/tractor combo goes through dips and hollows putting excessive down force on tail wheel...

bcp · May 17, 2021

Or, you could take it off. The rest of the world seems to get by without tail wheels.

Bruce

Henro · May 17, 2021

CMV said:
OK.....I'm doing something wrong.....way wrong.....and about to install my 3rd tail wheel fork on a 6' Bush Hog BH6 that's almost 3 yrs old. I figured the first one was due to the hydraulic top link failing, leaking down before I noticed, and i was just loading it up too much. But most of last season, I used the standard top link and this failure/damage happened after switching so that's not issue.

As far as I know, I'm not turning and smacking it into a tree, fencepost, some hard object. I have some hills, dips, ruts, and will occasionally dig a front corner into the dirt, but nothing so bad it should be loading up the tail wheel, but all I can think is a small ditch-like area I go over must do it.

I set to cut pretty short - about as high as a typical homeowner riding mower would cut at it's highest setting - 4.5" maybe?. At least i think that's short for a bush hog. On flat level ground the front of the frame (closest to PTO) is about 3" high. I adjust toplink so the back end (tailwheel end) is about 5-6" high. I think I'm doing that right - the rear slightly higher than the front. So maybe I'm overall just too low (I want about a finish mower height, but need something that can stand up to the occasional baseball-sized rock my land likes to just magically sprout). Maybe I need more of an angle and should have the back end more than just a couple inches higher? Not sure....I thought it was just supposed to be a couple inches higher to make it want to discharge rearward vs any random direction.

Anyway for standard cutting on fairly even ground the tailwheel doesn't touch the ground. Only inclines, ruts, hills, etc. I never really notice it loading up on the tailwheel, just that sometimes it does what it should and keeps the back end from dragging on uneven ground.

I don’t use my brush hog that much but as mentioned above by someone, or maybe several people, my understanding is the tail wheel is a tail wheel. You don’t run with a solid top link. You want the brush hog float on the tail wheel.

If you’re locking the back of the brush hog in place with the top link, you’re going to stress the fork assembly when it hits the ground during a dip, or at after a rise where the back of the mower wants to raise and can’t. (Same thing I guess)

My Woods BB60 brush hog has a hinged link where the top link is connected, so you cannot lock the BB60 (or tail wheel) in position.

jeff9366 · May 17, 2021

I adjust toplink so the back end (tailwheel end) is about 5-6" high. I think I'm doing that right - the rear slightly higher than the front.

Anyway for standard cutting on fairly even ground the tailwheel doesn't touch the ground.

Reset the tail wheel so it just touches the ground when you mow. Not with the TPH Top Link but by changing bolt positions in the tail wheel frame.

MoKelly · May 17, 2021

bearthebruce said:
Is the wheel pivot greased and free to spin?

Is the wheel greased and free to spin?

Can't think what else would tear up the wheel.

^^^^ This would be my guess. Easy to check.

I had the exact issue you had and found the pivot was not spinning properly. It was sticking. Drug the wheel and tore it up pretty fast.

I had to remove the existing zerk and put in a new one to get the grease inside properly. Once that was fixed all has been great.

I felt foolish but things happen.

Good luck.

MoKelly

CMV · May 17, 2021

Yes greased. Will have to get a pic. It's like the fork was smashed straight down from the top. Wheel spins freely, shaft pivots freely.

bcp · May 17, 2021

From:

https://bushhog.com/wp-content/uploads/2020/01/OP_MANUAL_-_BH4-BH5-BH6_PUB_10-19-1.pdf

Bruce

ning · May 17, 2021

My guess is that the top link is extended too far so there's not enough "float" in the system and sometimes you back it up something steep (or drive up somewhere that steepens rapidly). Something's got to give.

kneedeep · May 17, 2021

Use a big chain with big clevis for toplink. Adjust it to cut level with tailwheel carrying the mower and lift arms supporting the front.
You can still lift it when needed, no more smashing tailwheel.

kirkawilson · May 17, 2021

Only other thing I might suggest is to raise the tailwheel when making big turns to keep the torque off the tailwheel assembly and 3ph.

dirttoys · May 17, 2021

CMV said:
OK.....I'm doing something wrong.....way wrong.....and about to install my 3rd tail wheel fork on a 6' Bush Hog BH6 that's almost 3 yrs old. I figured the first one was due to the hydraulic top link failing, leaking down before I noticed, and i was just loading it up too much. But most of last season, I used the standard top link and this failure/damage happened after switching so that's not issue.

As far as I know, I'm not turning and smacking it into a tree, fencepost, some hard object. I have some hills, dips, ruts, and will occasionally dig a front corner into the dirt, but nothing so bad it should be loading up the tail wheel, but all I can think is a small ditch-like area I go over must do it.

I set to cut pretty short - about as high as a typical homeowner riding mower would cut at it's highest setting - 4.5" maybe?. At least i think that's short for a bush hog. On flat level ground the front of the frame (closest to PTO) is about 3" high. I adjust toplink so the back end (tailwheel end) is about 5-6" high. I think I'm doing that right - the rear slightly higher than the front. So maybe I'm overall just too low (I want about a finish mower height, but need something that can stand up to the occasional baseball-sized rock my land likes to just magically sprout). Maybe I need more of an angle and should have the back end more than just a couple inches higher? Not sure....I thought it was just supposed to be a couple inches higher to make it want to discharge rearward vs any random direction.

Anyway for standard cutting on fairly even ground the tailwheel doesn't touch the ground. Only inclines, ruts, hills, etc. I never really notice it loading up on the tailwheel, just that sometimes it does what it should and keeps the back end from dragging on uneven ground.

I think previous replies are dead on.

1. Let the mower rest on the tail wheel.
2. Use a chain for top link.

If you still break 'em the place is haunted

Best,

ed

DieselBound · May 17, 2021

Picture?

I've got an older BH, a 286. I busted the tail wheel on it not long after I'd had it. Got it welded with extra gussets (great suggestion by Xfaxman): it's held up fine since, in which case I am sure it'll never break again. I'm slamming into all sorts of stuff, backing into brush and finding all sorts of logs, root mounds and generally immovable objects. Though I operate in "dangerous waters" I try to go slow and feel my way.

pjbci · May 17, 2021

Might wanna adust the rate of drop for the 3ph.

WranglerX · May 17, 2021

CMV said:
Yes greased. Will have to get a pic. It's like the fork was smashed straight down from the top. Wheel spins freely, shaft pivots freely.

Down force applied because no flex in top link to rear of cutter.... Replace bar with a chain and try that.... chain allows cutter to float on tail wheel...

cqaigy2 · May 18, 2021

I don't have a tail wheel, but on my rough cut mower, the front wheels swivel and changing direction, forward/backward will sometimes get the wheels sideways.

ericm979 · May 18, 2021

That cutter comes with a pivoting link that you attach the top link to. The pivot link is supposed to give the cutter some play to move up and down at the back end, pivoting around the pins attached to the lower links. If you're not using the pivot link or connecting the top link to it so that the cutter can't move up and down at the back, the cutter will instead have to move the entire 3pt linkage up when the wheel encounters a rise. That will put more force through the tail wheel.

This type of pivot link does not have much travel. If you're mowing really hilly areas (like driving into a dip) or backing up to a bank you may be asking too much of it.