damaged gearbox filler plug

[dmsantam]

when I first changed the gearbox oil on my then new to me hexhead GS, I noticed the filler plug seating area was damaged, like somebody had gone at it with a punch. The threads are fine. Using a new crush washer, I managed to get it to seal with a little more than the recommended torque. it's time to change the gearbox oil again soon, and I wonder if you have any suggestions on how to deal with this issue. cheers

[lkraus]

For some reason, BMW used different plugs for drain and fill and it is likely someone once used the wrong wrench.  When the hole stripped out, they then used a punch or chisel to remove the plug.

 

Stuff a rag in the hole to keep chips out and scrape any raised areas down. Fill the low areas with a tiny bit of JB Weld epoxy to re-create a flat sealing surface. Keep the epoxy off the threads. The beginning of the thread is missing in the 2-4 o'clock area.  It won't be missed, but epoxy on the very edge would make it difficult to start the plug.

 

[dirtrider]

2 hours ago, dmsantam said:

when I first changed the gearbox oil on my then new to me hexhead GS, I noticed the filler plug seating area was damaged, like somebody had gone at it with a punch. The threads are fine. Using a new crush washer, I managed to get it to seal with a little more than the recommended torque. it's time to change the gearbox oil again soon, and I wonder if you have any suggestions on how to deal with this issue. cheers

Morning  dmsantam

 

I have delt with similar a few times before, as you mentioned usually caused by someone going wild with a punch or chisel. 

 

In the past I have just used a new (or properly annealed) crush washer, then put some pipe thread sealer with PTFE on the plug threads & a very light swipe of pipe thread sealer with PTFE on each side of the crush washer. 

 

The pipe sealer with PTFE actually seals the threads so the crush washer is just a backup. The pipe thread sealer with PTFE remains somewhat soft so it doesn't make future  plug removal difficult & doesn't  get hard chunks to fall into the transmission. 

 

I usually clean the trans case threads & the plug threads with brake clean so the pipe thread sealer makes a good bond.

 

Never had one leak or become difficult to remove the plug, just don't use a hardening or locking type thread sealer. 

[dmsantam]

thanks guys, I will give the ptfe thread sealant a go, as I have some in the workshop. cheers