Grinding Sound in Transmission

[krazzyman]

Just finished the Engine rebuild and the cub is running in one piece! such a relief. There is another problem though. This was present before we did the rebuild and it was a grinding sound in the back of the tractor and it has gotten worse. Here is a video of the sound. about half way through the video you can hear the abnormal sound.

https://youtu.be/LZ82z1Jx8XM

Any ideas what it might be? We have never opened the Transmission up before and it has been oiled correctly. I'm guessing I will have to open the differential and have a look. can you just take the back plate off of the PTO to have a look or is there more to it?

We wont be running it till we have this figured out.

Thanks

Ammon

[Slim140]

I'd say you have a bad bearing (or two) in the tranny.

[TallCoolOne58]

Most common ill, is worn input shaft rear bearing, which can cause other issues, like gear clashing and trans whine. Do you hear a grinding noise from behind the shifter with engine running and trans in Neutral (with clutch engaged)? If so, probably the culprit. However, may not be the only issue.

If you can safely jack up rear trans/ diff to get the tires off the ground, and run thru the gears, you may be able to pinpoint noise, esp using mechanic stethoscope. Sometimes the bearings and gears will only make a noise under pressure with a load on them. Exactly when the noise occurs is also helpful in the diagnosis, always, when driving uphill, or only downhill etc. You can research YouTube on trans/diff diagnosis to get a handle on the probable cause or causes, to give you an idea what you're up against, before you rip and tear for a visual inspection.

[egwhite77]

Both are good suggestions and I would also check fluids in both final drives and transmission. If you find metal in one of those locations it could be a good place to start looking. I am working on a 52 now and was going to just rebuild the engine and use it around the yard. A year later, the 52 is morphed into a total restoration. I glad I chose to go all the way. There were final drive bearings and seals bad, a chipped pinion, and as Tallcoolone58 suggested the the rear input shaft bearing was completely gone. So bad I had to purchase a new shaft. I have rebuilt both left and right differentials and will start putting transmission together next weekend. Engine is rebuilt and soon this project will look like a cub. Good luck.