Oil filter drain plug woes

So get a phone call from a mate today cursing me for jinxing (warning) him about the bottom cover drain bolt and how the threads get damaged etc.

He snapped it in there. Great i thought, I just got my m6 timesert kit in the mail so all should be sweet, drill it out and repair it so its better than standard

Boy was i wrong.

the bushings do not go past the first hole, and the countersink tool most definitely doesnt fit.

Thought, dont worry about the countersink part as it is not necessary for a flush finish as the thread already starts deep in the hole. So we drilled out the outer hole 0.5mm to accommodate the bushing.

Drilled the hole to size, tapped it than inserted the bushing and expanded it with the tool.

Damn thing wouldnt stay in there, upon tightening the screw it would just pull the timesert out

After lots of cursing by the owner (he was doing all the drilling btw as i didnt want to be responsible for any mistakes) he got the shits and drilled out the hole in the cover and used an M8 bolt and "threaded" it with a ratchet while i was watching in horror lol.

It worked well enough to hold but for how long who knows.

Now before i go and attempt this on my bike as its only its last threads so to speak, i have lots of questions

1) how the hell without taking off the side cover where the clutch sits in would you do this sort of repair?

2) If i used an insert long enough to block the hole, i would no longer have oil going there causing problems in the thread? (currently have 9.4mm insert i believe)

3) If i were to do the ball bearing mod, would i not need to block the hole with the insert

4) if i didn't cover the hole, i was reading something about loosing oil pressure, how is this possible? doesnt that hole just go from the filter well to the bolt?

5) is there supposed to be 3 small o-rings and 1 large o ring on the filter cover? Think he is missing one because it leaks wherever he doesnt use an o-ring


Edited by tek_01

  1. I've never used a Time Sert on this particular spot, but others have reported no problems with it. Yours obviously didn't work out. The one I did repair for a guy I used a long enough Helicoil so that I didn't need to break off the "tail" of it, so I did it with the case in place. Best to remove it.
  2. True. If the insert extends past the drain hole, you're good
  3. That's also true.
  4. The bolt hole is open at the inside end. With an insert, the hole is drilled to say 7mm, then install an insert that doesn't reach across the drain hole, that leaves a .5mm gap around the bolt for oil to escape though and run out the open end into the clutch housing.
  5. There's one big O-ring on the cover, and 3 small ones on the face of the case cover

Im almost 100% sure you cant use these from the front. A helicoil yes as the insert and the tool is no bigger than the hole but the timesert has an expanded end that is supposed to sit in a countersunk hole (which the tool itself is too big to fit deep into the hole)

Curious to hear from anyone who has done one from the front

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