Unstyled A transmission gear noise

[Derweibhai]

To all those with a 34-38 Deere A. How noisy is your transmission? I have a number of classic tractors and I am concerned about the amount of gear noise from my 36 A. While pulling the drive side of the gears is pretty significantly noisy. Of ccourse when coasting or with no load it goes nearly silent. From what I recall my 36 B and 39 H are pretty quiet. My Case SC transmission is pretty noisy in 3rd and 4th, but they are known for that. With the 36 A any amount of driving under load without hearing protection will cause damage to your ears.

 

[JIM MN]

What weight transmission oil are you using? You may try a heaver weight transmission oil, as SAE 140 plus a heavy oil additive. The transmission gear teeth are worn causing your noise. Gear teeth are meshing off causing the noise. Shaft bearings could be rough and loose? Heavier oil will help your noise problem.

 

[Derweibhai]

I am running 140wt specifically for that reason. I plan to pull it all down soon and replace any worn parts with ones out of a 37 parts transmission. Just wondered how loud they normally are.

 

[620 John]

Is the noise always there or is it only certain gears???

Most of the time on a two cylinder the gear noise is from the first reduction gear.

Earlier this year I had the RH countershaft bearing go out on my 37 A while pulling a spring tooth drag through the field. Put new bearings in the top shaft, countershaft, and first reduction shaft. After that the first reduction gear made more noise than before I tore apart the transmission. I think the new bearings changed the gear contact. Haven't had a chance to put it to the test with a heavy load yet. The noise isn't what I would consider terrible though.

My 620 on the other hand is another story... That thing howls pretty bad at the first reduction gear. I'm just waiting for the day that thing shells itself out because it's got a lot of hours on it and I don't think it's been rebuilt before. Hopefully I can get around to it before that happens.

All in all you could go through and put new bearings in it and the noise might not change. But at least you know it won't self destruct. I even had a bearing out on my 51 B and didn't even know it. It was the RH sliding gear shaft bearing. It might have been out before I owned the tractor though.

 

[Derweibhai]

All gears equally when under load. Talking anything from pulling a wagon so heavy it will stall out down do driving up an incline unloaded. The noise is always there unless coasting or dead flat ground.

 

[620 John]

If it's making the noise in all gears then most likely it's the first reduction gear making the noise. Good possibility the outer ball bearing that sits in the cover has worn the housing a bit which causes the first reduction gear to run crooked. So far I've gotten by with putting in a new bearing and peening the housing with a center punch then assemble with green loctite. But once again, the gear will probably still make a bunch of noise because the teeth wear pattern has changed.