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General => Douglas Motorcycle Discussion => Topic started by: Pallijen15 on 21 Nov 2021 at 18:32

Title: Gearbox battery carrier fixing
Post by: Pallijen15 on 21 Nov 2021 at 18:32
Hi, on my MKV the threaded holes which attach the battery carrier to the gearbox have been butchered. I want to put helicoil inserts in (1/4" BSF?). Would it be okay to do this with the gearbox in situ in the frame? Any help appreciated. Thanks,Paul J
Title: Re: Gearbox battery carrier fixing
Post by: My 4th bike on 21 Nov 2021 at 21:58
I don't see why not.
All I can add is use an insert at least twice the diameter (2.0D) or as long as possible.
Title: Re: Gearbox battery carrier fixing
Post by: eddie on 22 Nov 2021 at 06:43
Paul,
        Be careful if using inserts - the holes are blind and quite short, and it can be problematical installing the short inserts. If the bottom holes break through, you may generate another leak. On my bike, I just re-tapped the holes the next size up (5/16"BSF) and opened out the holes in the battery carrier to suit.

  Regards,
               Eddie.
Title: Re: Gearbox battery carrier fixing
Post by: Pallijen15 on 23 Nov 2021 at 16:38
Okay thanks for replies. Are Keenserts and Timeserts any better? Don't really want to tap these out to a larger size, what about studs and high strength loctite? Thanks, Paul J
Title: Re: Gearbox battery carrier fixing
Post by: My 4th bike on 24 Nov 2021 at 20:43
I like coils if I have to use any.
You could watch this, It may help your decision.
“Thread Insert Deathmatch! Helicoil vs TimeSert vs key locking insert vs BigSert”
https://www.youtube.com/watch?v=LpDduCVUy6w
I support Eddie’s method, retap 5/16 BSF.
¼ BSF stud with thread locker, if there’s enough thread left for support it, could be your first try.
Title: Re: Gearbox battery carrier fixing
Post by: Vitesse on 25 Nov 2021 at 09:36
Save us all 32 minutes - what was the outcome and why?
Title: Re: Gearbox battery carrier fixing
Post by: My 4th bike on 25 Nov 2021 at 22:16
Coils win.
If you thought to watch there are short cuts included.
If you want to skip the intro and go straight to the good stuff...
The torque tests start at 5:20.
The pull out tests start at 13:02.
Title: Re: Gearbox battery carrier fixing
Post by: Pallijen15 on 26 Nov 2021 at 15:16
Yes, good video that was. I've sorted it now anyway. One of the holes already had a metric helicoil insert in. But since it was only the  first two or three millimetres of the holes that were damaged I just fitted some longer bolts, there were enough good threads left. But I'll probably go for the helicoil kit if I need one in future. The video was very informative.
 Thanks, Paul J
Title: Re: Gearbox battery carrier fixing
Post by: Vitesse on 26 Nov 2021 at 20:14
Okay - worth thew half hour to watch!

Interesting that the steel bolt straight into the alloy was better in the pull out test than several of the inserts, though terrible at resisting over torquing. So, don't try to be clever and exceed the stated torque and the thing will hold!