I destroyed the gearbox on my brush hog.... help

[5030]

The higher the ratio of the gear box, the more input power it will require for it to maintain efficient operating RPM. So long as you have adequate input power, it's all good, but if it's marginal, I'd stick with the stock ratio.

 

[LD1]

And yes, 1.92:1 is fine on a 5' mower. Gives you a 16000 FPM blade speed as opposed to 12.5k with a 1.47:1 gearbox.

If this were a 6' cutter though, you do NOT want a 1.92:1 gearbox. Too fast. Almost 20k blade speed.

So when saying "looking for a cutter, if it aint 2:1 or close I aint interested" would ONLY apply if you were looking at a 5' cutter

 

[5030]

Can't go crazy with it, but if you want a bolt tight, a breaker bar seems to get a bolt tighter than a short handle ratchet wrench. Given the labor involved to fool around re-tightening bolts, I'd think about installing new bolts, nuts, washers, and lockwashers along with locktight as 5030 recommended. I'd also clean the mounting deck surface in case rust is keeping the bolts from firmly locking in place.

I tend to use a battery powered 3/8" impact wrench, in my case my Bauer 20 volt 3/8" impact to tighten down Locktited bolts as it won't over stress and elongate them like a 1/2" drive high torque will and is better than a breaker bar or hand ratchet because you can get very consistent clamping torque, which is always important with a cast steel or cast iron gearbox flange.

 

[masseyrider]

Everything wears out with time.
I like to replace with new when there is a catastrophic failure. New warranty and all that.
My old neighbor was of the mind to fix it. He had an older 8 foot pull behind that had seen better days.
It cost him almost as much to repair as the new 8 foot Bush Hog I bought at about the same time. 20 years later I'm still mowing and his has long gone to the scrappers.

 

[5030]

I'd say 99% of the replacement gear boxes come over in a container today.

 

[D&D]

overrunning couplers, something you really need for ANY shredder as a shredder will destroy your PTO brake in pretty short order from freewheeling if the PTO is disengaged while the shredder is turning at operating rpm.

You have me thinking that this is a really good idea. Wouldn’t a slip clutch do the same thing?

 

[5030]

You have me thinking that this is a really good idea. Wouldn’t a slip clutch do the same thing?

No. A slip clutch (like a Weasler) for example, only mitigates shock loads and slips when the imposed load overcomes the clamping pressure whereas an over running adaptor will 'ratchet' when the PTO stub stops turning until the implement ceases rotation. It's that freewheeling rotation that destroys the PTO brake. I use them on every implement that can freewheel the PTO stub when the PTO is disengaged and the PTO brake is actuated.

 

[ROUSTABOUT]

You have me thinking that this is a really good idea. Wouldn’t a slip clutch do the same thing?

Slip clutch is nothing like an overrun clutch and has no similar qualities.

 

[ROUSTABOUT]

And yes, 1.92:1 is fine on a 5' mower. Gives you a 16000 FPM blade speed as opposed to 12.5k with a 1.47:1 gearbox.

If this were a 6' cutter though, you do NOT want a 1.92:1 gearbox. Too fast. Almost 20k blade speed.

So when saying "looking for a cutter, if it aint 2:1 or close I aint interested" would ONLY apply if you were looking at a 5' cutter

I can run the engine at lower speeds and get a good cut.

 

[D&D]

No. A slip clutch (like a Weasler) for example, only mitigates shock loads and slips when the imposed load overcomes the clamping pressure whereas an over running adaptor will 'ratchet' when the PTO stub stops turning until the implement ceases rotation. It's that freewheeling rotation that destroys the PTO brake. I use them on every implement that can freewheel the PTO stub when the PTO is disengaged and the PTO brake is actuated.

Right, thanks for confirming