Oil Filter Lower Bolt thread damage prevention

After coming across this thread http://www.thumpertalk.com/topic/548754-preventing-thread-damage-to-the-lower-filter-cover-bolt/, ironically due to someone posting in the WR forum who had a YZF, it got me thinking about mine, and why I wasn't aware of this, and why its not in the stickies.


The lower bolt on my 08 '450 has always been a bit stiff so I decided to take a look

Thankfully the thread look OK, but running a tap down it, did get a surprising amount of aluminium crap out of the threads and stuck to the tap

When I checked the hole, it was a bigger diameter than that quoted in the thread above (0.120" / 3mm). Its unlike GrayRacer to be wrong so perhaps WR's or European bikes have bigger holes.

The hole in my bike was bigger than 4mm, but less than 4.2mm.

As 4.2mm is the drill size used when tapping a hole to M5 x 0.8 thread size, I decided to run a tap down it and put a grub screw in the hole, as I already had some M5 grub screws


The hole is about 12mm long, so I tapped the thread about halfway down, to enable the grub screw to bottom out in the thread and allow some torque to be applied to it

Standard length taps do the job just fine, as they are long enough to reach past the top oil filter housing and get a tap wrench onto them

A bit of loctite 270 on the grub screw and the job is perfect


I wouldn't recommend doing it on the bike, as the swarf from the thread tapping does seem to get into the most unlikley places

It only takes 10-15mins to get the cover off so better safe than sorry

I put some pvc tap over the oil feed hole to stop and swarf going in there

There advantage of taking the cover off is that you can blow any swarf that's fallen in the oil filter bolt hole straight through out and onto the bench.



Edited by GuyGraham

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