rotary cutter deck cracking

[Kaon99]

This past weekend I noticed the deck on my 48" rotary cutter (brushhog/bushhog) is cracking in two places. The deck is roughly octagon shaped. On each side, at the corner where the slant side meets the parallel side, the deck has a 1" crack that seems to be getting bigger. The steel is very thick, so I was very surprised to see the cracks. I have used the rotary cutter in some heavy brush, but I am not aware of doing anything drastic enough to crack the deck. I talked to Terry at Power-Trac and he said he had never seen a cracked deck on a rotary cutter.

I think the deck can be easily welded so I am not too concerned. However, I suspect the deck had a defect in the steel, so am making this post to see if any of you have had a pt mower deck crack. I will appreciate any information you can give me. Thanks- Ken in Mississippi

 

[MossRoad]

Sorry to hear that. /forums/images/graemlins/frown.gif

I have less than 10 hours on our 48" brush hog from PT. No signs of wear on the deck. Just blown out tires(replaced with solid tires) and a missing blade(hit a rock and cracked off the bolt). Other than the tires, I've been very impressed with mine in the short time it has been used. We'll use it more when/if we move to our property.

Do you have a way to take a picture of it and post it here?

 

[smartguyz]

Hi MossRoad -

I expect my Brush Hog's tires will not survive the blackberry brambles that are in its future. Where did you get solid tires, and what size did you get? I think that the tires may be the same size as for the 48" finish mower, so this would leave a spare pair of tires for the finish mower.

Thanks,

Rob /forums/images/graemlins/grin.gif

 

[Kaon99]

Mossroad,

That's a good idea. I will take some pictures soon and post them. I am quite puzzled as to how I managed to break a heavy steel deck. Maybe the pix will generate some theories.

On another topic: I solved my rotary cutter flat tire problem (so far) by putting in heavy duty slime-like sealer from NAPA ($12 for 32 oz - 16 oz in each tire) and pumping the tires up to about 40 psi. I have used the rotary cutter to clear an acre of head-high kudze and to clear out sapllings, thorny bushes, etc., with no further problems.

Look for some pictures soon. - Ken in Mississippi

 

[Kaon99]

Here are some pictures of the two cracks on my 48” rotary cutter. This post shows the right-side crack from a couple of feet away. The following posts show a close-up view of each side. If you have any theories as to what caused the cracks, I would like to hear from you. Thanks. – Ken in Mississippi

 

[Kaon99]

Here is a close-up view of the right-side crack. - Ken in Mississippi

 

[Kaon99]

Here is a close-up view of the left-side crack. As you can see, the two cracks are in the same places relative to the front of the cutter and are practically identical. My guess is either the steel is defective or else I somehow put a terrific strain on the front end of the cutter. At any rate I think I need to make an appointment with the local welding shop.

Ken in Mississippi

 

[SnowRidge]

</font><font color="blue" class="small">( My guess is either the steel is defective or else I somehow put a terrific strain on the front end of the cutter. At any rate I think I need to make an appointment with the local welding shop. )</font>

Ken, I stared at those photos without seeing any obvious cause.

My guess is the steel was under stress from the day it was welded up, and the vibration over time finally caused it to crack, thus relieving the stress--but it's only a guess.

SnowRidge

 

[MossRoad]

Hmm. It almost looks like a tremendous load was placed on the front, causing it to pull out like that. I'd just get it welded up and see if it returns. Do you use the hog in FLOAT? Maybe it came out of FLOAT or something and the entire weight of the tractor went onto the front casters instead of the front wheels. Imagine going towards a steep incline, the curl function of the joystick all the way back and not in FLOAT. The front casters could bear the entire weight of the tractor causing the front wheels to come up. Just thinking out loud. Hmm... Maybe somone dropped it on the front casters in shipping and it is just now becoming apparent. Hmm.. this is puzzling. Thanks for the pictures. I'll inspect mine the next time I pull it out of the garage in a few weeks.

 

[Bob999]

It appears to me that the load and stresses from the front castor wheels on the rotary cutter are trasfered to the plate steel that forms the top of the deck. Excessive loads would tend to cause this plate to flex.The joint you show as cracking would be stressed by any deflection caused by the loads from the front castor wheels. The thing that struck me about the cracks is that there is gap in the lower inch or so that suggests that there was never a solid weld all the way to the bottom of the skirting. It certainly wouldn't be the first case of defective welding.

An alternative theory is that the absence of draft control on the 425 puts higher loads in this area as compared to the decks that are used on the 1400 and 1800 series tractors. The manual for my 1845 says"...weight can cause damage to the gage wheels on the back of the mower and the caster forks on the front of the mower."