Transmission noise in 2nd and 3rd gear.

[fishcop 126]

I'm restoring a 1949 Cub and have encountered a clanging noise in 2nd and 3rd gear while in motion. No noise in 1st or reverse. When I had the tractor apart I flushed the transmission and differential with diesel fuel 3 times until all of the gunk came out and then put in new 90w. The clanging doesn't seem to affect the forward motion of the tractor. I've posted a short video to youtube of the noisy condition. Any hints or assistance will be welcomed!

[John *.?-!.* cub owner]

the you tube link does not work for me, but the clanging in 2nd and 3rd would possibly indicate a problem with the shifting fork. Loose, bent, or broken. That will be the fork on the left side of the transmission.

[Jim Becker]

I fixed the youtube link.

[fishcop 126]

I'll take a look at that. When I got the tractor it was a rust bucket but the shifter/transmission cover was yellow and appeared to have been changed at some point. Thanks for the information, I'll let you know if that was the issue!

[John *.?-!.* cub owner]

After listening to the You Tube, my first idea still seems reasonable. A broken tooth on a gear would be a possibility, but on 2 gears highly unlikely. Might try jacking it up and see what it sounds like with both wheels off the ground. You can block the clutch and put pto in gear to turn the shaft. It almost sounds like a piece of metal stuck between the teeth of one of the gears.

[fishcop 126]

Thanks John, That will be something I'll look at. I did look at the gears that I could see when I had the shifter cover off. Didn't see anything broken but I didn't completely disassemble the transmission. I will check the shifter fork assembly first and go from there.

[Crimson Tim]

Am I right in thinking that 2nd and 3rd gear share a shaft that 1st and Reverse do not use? I would look first explicitly at that shaft.
I would:
- Block up one back wheel off the ground
- Take the cover off the transmission
- Tie or block the clutch pedal fully depressed
- Put in second or third gear
- Spin by hand the wheel that is in the air
- Observe and listen for anything unusual going on in the transmission.

It seems like whatever is going on should be readily apparent with the top off.
Caveat: I have never been into a cub transmission personally, so this is offered with in the spirit of adventure and exploration. If the top is off the transmission, does that pull the shift forks out? Dunno. Probably. If so, you'll have to manually hold it in gear with a screwdriver or something while someone else spins the wheel.

It's strange that the noise should pop up after doing nothing more that flushing the gunk out. May a broken gear tooth was suspended in the gunk safely out of the way, but now it is free to move around and is touching something it shouldn't? I will be very curious to see what you find.

[RaymondDurban]

Am I right in thinking that 2nd and 3rd gear share a shaft that 1st and Reverse do not use? I would look first explicitly at that shaft.

All gears ride the same upper input shaft and same lower countershaft.

Caveat: I have never been into a cub transmission personally, so this is offered with in the spirit of adventure and exploration. If the top is off the transmission, does that pull the shift forks out? Dunno. Probably. If so, you'll have to manually hold it in gear with a screwdriver or something while someone else spins the wheel.

Pulling the shifter cover will not remove the shifter forks. To switch gears with the cover off will require a large screwdriver or small prybar and they should stay in that position (detent) until forced back to neutral.

Did the transmission have this noise before restoration? Without any other information, I agree with John, look for a bent/cracked/misaligned second/third shifter fork.

[pickerandsinger]

If you didn't leave a crescent wrench in there I'd go with John also…. Dave

[havoc1482]

Sounds like my Super A. The only reason I don't do anything to fix it is because I know that its a chip in my oiler gear. Meaning: its non essential.

That being said, I'd have to agree with John, you may have a chip in a gear or worst case scenario a broken tooth.

[fishcop 126]

Yes Ray Durban, it was noisy before restoration, I only ran it briefly before I started working on it and I thought flushing the gunk out of the transmission might have solved it but it didn't. And thanks to all for the good suggestions of things to consider. I'm a handy guy but by no means a mechanic.