Gearbox Thumping

[simowills]

Hi All,
General advice needed. My 2014 750D with DCT has developed a thump in the transmission. Sounds BAD, something trying to get out, by the sound of it. I'm thinking out a replacement engine gearbox unit if something is available somewhere. I am in Melbourne Australia, there were only a small number of these sold here, can't find anything in wreckers, thought I would just ask the question here about the possibility of something there?????
The bike has about 75,000 km's on the clock so a low km replacement sort of makes sence.
thanks

Simon

 

[dduelin]

The engine and transmission are one combined unit in the NC700/750 series. A few are listed on eBay right now with manual transmissions.

 

[simowills]

The engine and transmission are one combined unit in the NC700/750 series. A few are listed on eBay right now with manual transmissions.

Thanks I will look again.
Simon

 

[davidc83]

You sure it is in the transmission and not behind the front sprocket cover? Does your chain have tight or frozen links? The front sprocket cover has a tab on the backside. A stiff/stuck/frozen links will hit this tab and sound like a bad thump from the transmission area. Don't ask me how I know.....

 

[simowills]

Thanks David, I have had that cover off to check "stuff", but I will check again.

cya.

 

[simowills]

Thanks I will look again.
Simon

Thanks I will look again.
Simon

The engine and transmission are one combined unit in the NC700/750 series. A few are listed on eBay right now with manual transmissions.

Hi dduelin, no NC, complete engine assemblies are on the Australian eBay site, cams, gearsets etc, but no assemblies. If you have links i could use???
Thanks
cya.

 

[670cc]

I’ll second davidc83’s suggestion about checking the final drive chain. Just yesterday my NC, with a very old chain, developed the knock again. It‘s a very loud knock/thump at seemingly random intervals when riding at low speed, clearly audible over engine sound and through ear plugs. It may knock a few times in succession, then skip a few beats, then knock again once or twice. I know it’s the chain because I’ve experienced it before. Today I’ll be swapping out the drive chain.

 

[davidc83]

I’ll second davidc83’s suggestion about checking the final drive chain. Just yesterday my NC, with a very old chain, developed the knock again. It‘s a very loud knock/thump at seemingly random intervals when riding at low speed, clearly audible over engine sound and through ear plugs. It may knock a few times in succession, then skip a few beats, then knock again once or twice. I know it’s the chain because I’ve experienced it before. Today I’ll be swapping out the drive chain.

Yep, I use this thump as a sign to buy a new chain. Simon, check your chain for kinks. More than a couple, buy a new chain. If the engine starts and you can ride it, doubt it is the engine or tranny.