Tiller gearbox repair

[Aggie66]

I’m pretty sure the gearbox on my tiller has an internal problem. I’ve never gone into a gearbox like this and if someone has, I would appreciate conversing with them on exactly how to proceed. Mine is a 70 inch tiller by TMG industrials thank you.

 

[Harry in Ky]

More details. What's "a gearbox like this"?

 

[CliffordK]

I'm guessing you have something similar to this.

https://www.tmgindustrial.com/products/70-working-width-rotary-tiller-3-point-hitch-mount-gear-driven

It seems to indicate that they do sell parts, but I don't see an actual parts diagram.

TMG-RT175 70" Working Width Rotary Tiller, 3 Point Hitch Mount, Gear Driven

Product Manual Download here

parts.tmgindustrial.com

The ad seems to indicate 100% gear driven.

So, what to expect.

Coming off of the PTO shaft, for the 90° gearbox, I think there are two choices. Either a ring and pinion, or a worm drive. You might be able to estimate which you have based on symmetry. A worm drive may be slightly more symmetrical than the ring and pinion. Ring and pinion is probably the most likely.

The box on the side can be either belt drive, chain drive, or gear drive. Everything seems to indicate that it is actually a gear drive. My guess is that you have 3 gears. An upper gear, middle idler, and lower tiller gear, with the shaft for the idler gear being visible in the photos.

 

[CliffordK]

As far as faults, we're just guessing here. You should have 2 gearboxes that may have different symptoms.

Broken teeth? Gears pushed apart so they don't mesh properly? Bad bearings or bushings? Oil leaks?

 

[Aggie66]

This is the gearbox. I’m fairly certain there is gear damage inside if I take the PTO input shaft and turn it the times were turned, and then the shaft will start to slip and you can hear teeth, not mashing inside. I know I can remove the rear plate, but I’m certain whenever I take that off there’s gonna be a beer bearing suspending the input shaft gear so I don’t know how to proceed from there to be able to look inside the gearbox cavity to see what’s wrong. Do I just punch out the input shaft forward remove the seal and punch it out then pull the bearing. Is it a pressed fit bearing I just have not been able to find anybody that has actually done a repair on something like this and being my first time to do it I just was hoping to have someone say this is what you Gotta do

 

[Harry in Ky]

Having been through a few hundred gearboxes I can assure you they're all similar. yet all different. You have to start somewhere. Take the back cover off and see what that shows you. I suspect you will need to actually remove the gearbox to make repairs which will probably involve the tube and shaft to the outer side gearbox as well unless you can remove enough of the left side framework to allow the box to separate to the left. I can't tell enough from the one photo to make that call.

 

[CliffordK]

Also save your oil. That may help you discern what is going on. Chunks of metal? A little metallic reflections? Does a magnet pick up anything interesting.

 

[true temper]

Your problem isn’t that box. It’s the one on the side with the chain in it.

 

[jigs_n_fixtures]

This is the gearbox. I’m fairly certain there is gear damage inside if I take the PTO input shaft and turn it the times were turned, and then the shaft will start to slip and you can hear teeth, not mashing inside. I know I can remove the rear plate, but I’m certain whenever I take that off there’s gonna be a beer bearing suspending the input shaft gear so I don’t know how to proceed from there to be able to look inside the gearbox cavity to see what’s wrong. Do I just punch out the input shaft forward remove the seal and punch it out then pull the bearing. Is it a pressed fit bearing I just have not been able to find anybody that has actually done a repair on something like this and being my first time to do it I just was hoping to have someone say this is what you Gotta do

Is there a nameplate on the gearbox with the manufacturer and model? Given those you can sometimes find instructions and exploded diagrams online. Not knowing you experience level, try not to mangle seals and bearings as you disassemble it. Seals and bearings will normally have a manufacturer and model number on them, which can be cross referenced to parts from other manufacturers which parts houses such as NAPA can get for you.

 

[Aggie66]

Your problem isn’t that box. It’s the one on the side with the chain in it.

Thanks. I had to replace the seal on the driven side and it’s gear driven and all are good. Thanks for the advice.