Help please, 09 TYM T330 hydrostat with ratcheting sound from the rear.

[Vmax540]

Hello, I have a 2009 TYM T330 with a LT300H F.E.L and backhoe and tires are loaded. With front bucket edge vertically down to back drag and level a ground pile of hard clay and rock in low range and all of a sudden I hear this metal like gear ratcheting/skipping sound from the rear. Tractor still moves in all ranges fwd/reverse without any sound. It is only when under fairly heavy load will it ratchet or skip. On another note as I have mentioned before the front tires spin in or out of 4wd. This sounds expensive... Thanks for any help.

 

[K5lwq]

I would start by marking the rear tires to the rims. With loaded tires it is not uncommon for the rims to spin in the tire and could make a sound like you describe. Try working it again then see if the mark moves. Solution is put a little more air in the rear tires.

 

[JTKub]

Have you checked the filters/oil for metal?

 

[Vmax540]

Thanks for the replies, it really does sound like metal on metal although I can't imagine any main gear('s) slipping on each other and still operate normally in all ranges with no sound unless under heavy load. Also, one would think the hydrostat would go/slip before steel gears strip ? Even though it only has ~900 hours I still change the transmission filter each fall so, I will go ahead and do it now. I marked the tires.

 

[JTKub]

Does it make the noise in all ranges, plus 2wd and 4x4? Does the diff lock make a difference? Does the sound change when you turn the front wheels hard in either direction while you back up? Like you say, being HST, nothing happens in reverse in the gear case other than the HST changing direction and making the transaxle spin in reverse.

Just throwing stuff out there to help pinpoint.

 

[Harry in Ky]

It's quite possible you noise is external not internal at all. Check the wheel bolts where the center dish bolts to the rim. This is a common problem. I've replaced many of those bolts on many different tractors. The nuts may be tight on the bolt threads but the parts themselves can be loose enough to slide around as the wheel rotates. Look for signs of movement where the dish contacts the rim. If it has been sliding around the paint will be gone and bare metal will be showing. That condition will definitely make some strange noises while driving.

 

[boomer1025]

Check the diff lock linkage. Make sure it's fully disengaged.

 

[Vmax540]

Thank you to all for the suggestions, sorry it's been a while to reply (family....). Looked at differential lock linkage and it is intact on the outside of rear end. Now the latest, pushing into a road berm pile left by the state the rear tires will not turn under heavily load although the front tires spin and ratcheting occurs, especially in reverse, this can not be good... Again thanks for any help.

 

[Harry in Ky]

You're right. It's not good. Does the tractor pull at all when in 2WD? I've seen similar situations with small tractors where the ring gear bolts shear off. Not a simple fix.

 

[Vmax540]

The tractor moves fine in all three ranges locked in 4wd or not and only skips under very heavy load. Also I’ve mentioned it here before that the front wheels spin digging dirt with the lever in or out.