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Stripped sump drain thread

Posted: 04 Jun 2009, 12:27
by DevonAid
On Sunday I borrowed a friends drive so I could do a 'quick' oil change. On re-tightening the drain plug it went all loose on me - official disaster: the sump plug hole had stripped it's threads.

Much nashing of teeth and concerns over this coming weekend's trip being cancelled. There is quite a bit on the forums to help with this (as I always say: this is a great club) but thought I'd add my penneth-worth to help anybody else in the same situation:

1: Best course of action was deemed to be a helicoil repair in-situ. I obtained a kit from AR-sheldon but in actual fact I have since found you can also order it direct from Uni-thread (http://www.uni-thread.com" onclick="window.open(this.href);return false;) and it's a bit cheaper too. Size on my DF engine is 14mm x 1.5 thread. The chaps at Uni-thread are also very helpful/knowledgeable as I wanted to check I had the right kit, they talked me through it and made the good suggestion to practice helicoiling a piece of wood - great idea!
2: The stripped out sump hole was just about the right size for the tap so I didn't use the drill that came with the kit: this was handy as drilling an aluminium sump with such a big drill bit might be hard to control.
3: The kit does not come with a tap handle: my tap handle was just too small to hold the large tap: I used spanners as time was short but this made aligning the tap with the centre axis of the hole tricky. If doing it again I would either get a bigger tap handle or gentle grind the edges off the tap, allowing more control when starting the thread.
4: Plenty of grease on the tap to catch as much of the swarf as possible; pick bits out of the hole as you progress; wind the tap out as you progress to clear the hole
5: Just go deep enough but not too deep to avoid pushing any swarf into the sump.
6: Helicoil insert goes in; it can be cut shorter with side-cutters with it partly inserted as the coil is a little long. Wind the rest of the coil in
7: Once fully 'home', CAREFULLY snap off the break-off tang using long-nosed pliers (don't drop it inside the sump).
8: I flushed out the sump by adding some oil with the plug still out.

It all seemed to go together fine and so far is oil-tight (unlike the rest of the engine). The 'quick' oil change started on Sunday and finished Wednesday night.

Hope this is some help to others. Good luck!

Re: Stripped sump drain thread

Posted: 04 Jun 2009, 12:30
by xpress
damn sounds like a right pain, unfortunately for cars over a certain age it's quite common to have to get into a little metalwork here and there

:S

Re: Stripped sump drain thread

Posted: 04 Jun 2009, 13:48
by ermie571
Same thing happened to Tigs in cornwall.....no helicoil and no recovery....so the suggestion was made to araldite it in...gave it overnight to set, filled with oil the next morning and it got her home!!


Em
x

Re: Stripped sump drain thread

Posted: 04 Jun 2009, 14:01
by Titus A Duxass
so the suggestion was made to araldite it in...
That is an acceptable repair policy for some aerospace gearbox screws.

Re: Stripped sump drain thread

Posted: 04 Jun 2009, 14:10
by R0B
ive seen a spark plug used in an emergency..

Re: Stripped sump drain thread

Posted: 04 Jun 2009, 17:41
by jamesc76
R0B wrote:ive seen a spark plug used in an emergency..
I've seen them not just for emergency's but in for a long while!