Thread: LT230 - whine in high gears

LT230's are known to whine, and be just fine for a very long time.

I find however that the whine on mine (lets have a rhyme) has nothing to do with what gear I am in, it just gets more audable the faster I go.

Drop the oil, remove the cover plate and eyeball the gears. If it looks OK, try a quality oil and hopefully it will shut up some. Alternatively you could have a go at changing the bearings. No idea how easy/hard that is - I just bought an ashcroft rebuild... and it whines!

Gear noise results from loss of conjugate action. That can result from poor accuracy of the tooth profile during manufacture or wear.

Gears rarely wear in to improve the profile accuracy. This is because they are subjected to rolling contact close to the pitch line with sliding contact increasing toward the tip or root. Also because the pressure and contact stress change over the tooth profile.

The wear and noise will get worse with worn bearings because they can't maintain the mating teeth in proper alignment. The misalignment also affect strength and wear, as do the dynamic forces created by loss of conjugate action. Replacing worn bearings will help, both strength and noise, but won't prevent worn gears from creating noise.

Check the input shaft bearings. These get the least oil. I regret not checking mine last time I had the case out.