Clunking in Geared Hub

[AntiBNI]

Hello everyone, I am posting here as my last resort because I can't figure out why my geared hub is clunking.
I replaced both the upper bearings where the shaft mates and one of the races (the input side race) because it was rusty. None of my other 3 hubs do this, this is the only one. I can keep throwing more money at it and replacing all bearings but I want to make sure its not user error but an actual issue with the hub.

Any tips, insights, anything will be of great help at this point I want to get my baby back on the road.

Here is a video of the clunk: https://photos.app.goo.gl/2hJQzgbgh7TUew8R7

Model: M1123
Geared Hub: 12k
Replaced: 2 bearings on input side, 1 race on output side (cover side).

 

[Mogman]

A couple things, one you do not have the spindle nut locked in correctly, never re-use the locking tabs, second you have the hub upside down so I am assuming you replaced the spindle (upper) bearings, why only one race? I usually always replace bearings in sets, third did you disassemble the input bearings and inspect them, did you use new shims and set the input bearing preload with a dial indicator?
EDIT, when you turn it backwards the noise is running about 2:1 with the spindle so I would look at the input (pinion) bearings.

 

[AntiBNI]

Hey Mogman, Thanks for the reply.

"one you do not have the spindle nut locked in correctly, never re-use the locking tabs,"

Yeah, I have new lockwasher and spindle nut, I am re-using the old until I can figure out what is going on, its like the 3rd time I take the hub apart.

"second you have the hub upside down so I am assuming you replaced the spindle (upper) bearings, why only one race?
usually always replace bearings in sets"

Yes, I replaced both bearing of the drive gear BUT I did not check backlash assuming that it had the correct amount of spacers and should be ok, guess not lol. That hub was repaired not so long ago in Fort Sill, LCR but when I bought the M1123, it was missing the drive shaft for that hub, the input hole plug fell ,it got some moisture and developed some rust in bearing and the one race I replaced was pitted, the other bearing and race is pretty much new.

"hird did you disassemble the input bearings and inspect them, did you use new shims and set the input bearing preload with a dial indicator?"

This is what I did not do, I will buy one right now and check the backlash on both drive and driven gears.[/QUOTE]

 

[AntiBNI]

I looked on eBay and bought a new hub for cheaper than some people are selling used ones. I will prob just sell this one for parts.

 

[Mogman]

Hey Mogman, Thanks for the reply.


Yeah, I have new lockwasher and spindle nut, I am re-using the old until I can figure out what is going on, its like the 3rd time I take the hub apart.


Yes, I replaced both bearing of the drive gear BUT I did not check backlash assuming that it had the correct amount of spacers and should be ok, guess not lol. That hub was repaired not so long ago in Fort Sill, LCR but when I bought the M1123, it was missing the drive shaft for that hub, the input hole plug fell ,it got some moisture and developed some rust in bearing and the one race I replaced was pitted, the other bearing and race is pretty much new.


This is what I did not do, I will buy one right now and check the backlash on both drive and driven gears.

[/QUOTE]
What you are measuring on the pinion shaft is the bearing preload, you set that preload on the spindle shaft when you torque it.
There is a procedure for checking the gear backlash but you can't do anything anyway about it, so if the gear teeth look OK I would not worry too much about that.
SO if you have inspected all the bearings and they are ether good or replaced and have a "tight" spot you may want to check again to make sure all the races you did replace are fully square in the case.

You can pull the spindle shaft AGAIN (I know been there) and see if the pinion shaft feels like it has a tight spot and work your way from there.

 

[springer1981]

No specific words of wisdom here but general troubleshooting ... since you have obviously had it all apart a couple of times, I would remove each part individually and see if anything is still making a clunking noise. For example, remove a gear and spin the remaining to see if the clunk persists. Maybe this will help you identify the source.

 

[AntiBNI]

No specific words of wisdom here but general troubleshooting ... since you have obviously had it all apart a couple of times, I would remove each part individually and see if anything is still making a clunking noise. For example, remove a gear and spin the remaining to see if the clunk persists. Maybe this will help you identify the source.

Yeah that is what I did, and it only clunks when both gears are in place. and it only clunks in 1 spot lol.
I just bought a new hub just to move along with my project but I will double check the races, including the ones I left to see if they are square like Mogman suggested.

 

[MarkM]

Preload is oh so important so the gears will mesh properly.

Very good recommendations on the above posts.

Mark