Lost XR400 oil drain plug on trail

[blackadder]

Anyone had the oil drain plug at the bottom of the frame down tube vibrate loose and fall out? Mine did that yesterday. My riding partner noticed the oil dripping and stopped me before I ran it dry, and we managed to go back and find the oil plug. That was lucky - and we also found a kind cranberry grower nearby (we were riding in the pine barrens) who gave us 2 quarts of diesel motor oil so we could get moving again.

I'm puzzled about the drain plug. I'm reasonably sure it got torqued to spec at the last oil change. Do I need to safety wire it?

[ghostbuster2]

I safety wire mine. On my offroad race car I would put a dab of RTV on the fastener or threads to keep undrilled semi critical fasteners from loosening up. The drain plugs only fall out when not tightened enough, I use a torque wrench and a new washer everytime I service my bike.

[Trailryder42]

Ya know, I've never heard of that happening. I think the only thing you can be reasonably sure about at this point is that it fell out. I find it hard to believe it could have been caused by vibration. Where-as, vibration is usually the culprit where 2 or more sub-assemblies are held together with fasteners and that's how they get their ridgidity as an assembly. Any flex in the assembly as a whole makes the fasteners susceptible to vibration. The way the frame is put together in the drain plug area, everything is a soild, welded assembly and the drain bolt fastens no other assembly. To my mind, it would take an extremely hi freq. vibration to get that bolt to vibrate loose from a tightened condition. You might not have tightened it completely last time.

Safety wiring it certainly couldn't hurt tho.

[Kev_XR]

How many times did you re-use the crush washer?

I bought a used bike and the crush washer looked like it was hit with a 50lb hammer. It was beyond flat and used up.

[boatxr]

if it was torqued properly with a torque wrench it should not come loose.

[blackadder]

How many times did you re-use the crush washer?

Hmmm, that could be it. I usually don't reuse them, but as I recall I did this time. It didn't look beat, but maybe I just learned something.

[GUMBYXR400]

I seem to remember when mine fell out I possibly may have hand tightened it and not wrenched it down. Pretty funny story.

https://www.thumpertalk.com/forum/showthread.php?t=278880&highlight=oil+plug

[Zappa]

I seem to remember when mine fell out I possibly may have hand tightened it and not wrenched it down. Pretty funny story.

https://www.thumpertalk.com/forum/showthread.php?t=278880&highlight=oil+plug

I was just about to look for that! Good resourcefulness there!

Are you sure you had the torque wrench set properly? It's a weird problem.

[redrider7202]

hum, apparently they should add to the pre-ride checklist "check oil drain plug... tighten as needed"

[Sundog]

hum, apparently they should add to the pre-ride checklist "check oil drain plug... tighten as needed"

Errr...in regards to the thread listed above it should be "check spark plug...tighten as needed".

[Red_Snapper]

Anyone had the oil drain plug at the bottom of the frame down tube vibrate loose and fall out?

I'm puzzled about the drain plug. I'm reasonably sure it got torqued to spec at the last oil change. Do I need to safety wire it?

The frame plug has such a high torque that I wince everytime I tighen it. I'm guessing you spaced out torquing it.

[blackadder]

I just checked the shop manual. It say torque spec for the oil drain bolt is 29 ft-lb. And I probably could have spaced out while torquing it. Old geezers like me do that sometimes.

[Red_Snapper]

Well, don't have a senior moment and torque the engine case drain to that same torque or you will really be singin' the blues.

[XR_RON]

This is not normal,no way it could happen unless you forgot to tighten it.And when you said you were lucky to find the plug out on the trail,you werent just lucky,you were way way beyond lucky,the odds of that happening is about the same as winning the lottery,or getting struck by lightening twice,torque those plugs just to be safe.

[fendermon]

With dry threads I'd imagine.

[XR_RON]

Dry threads on an oil sump plug? that will be a good trick!!!!