Worn out oil drain thread

[Etienne B.]

Hi chaps,

Quite a long time without any involvement in Mark's forum, and in any Mini adventure that is - too much work and a new baby. But I managed to achieve my S wiring and electrical upgrades in order to attend Le Mans Classic this week-end. Started first time without any trouble, until ... after draining the old oil and changing the oil filter I tried to refit my oil drain plug - in vain. The casing is just worn out.
The previous owner - or a previous owner - had fitted a strange plug - looking like a Renault one, with what seems to be a metric thread. I made - poor quality I fear - pictures along a SPi plug I had in the shed ...
I believe fitting a helicoil would be the best choice, but I am reluctant to do it without stripping the gearbox as you can't see how the helicoil has been bedded in. Plus I haven't found a place in France to find the right one.
Has anyone here had any experience with Mini Spares DP2 self tapping plug ? How does it behave ? Can you really unplug and replug it for changing oil any other time ?? I am tempted because it could allow me to run the car while I am building a new engine - which might take me a while as usual !!!!
I would appreciate any help ! Rich ???!!!!
Cheers,
Etienne

[Vegard]

I'd Helicoil it, no doubt. You can buy a kit from Minimania rather cheaply.

[IAIN]

I would Helicoill it. I have had to do a number now all have worked well, stronger than the original and you use the original sump plug. If you are worried about swarf, drain the oil and get someone else to slowly pour the oil back in the engine as you drill the hole, the oil will bring out the swarf. An old tooth brush can be used to get any thing that might be left before fitting the Helicoil insert.
Just make sure you drill it square.

[Chalkie]

I had mine welded up then redrilled and retapped just easy as casing went off to be machined anyways

[Tim]

I had mine drilled and tapped to a larger size and fitted a different plug.

Tim

[251 ENG]

Get a time sert fitted , much beter than a helicoil .

We fit them all the time

[Vegard]

Simon, just for clarification. Do you find Time-serts better than Helicoils for all purposes, or just this one? If so, why? Just curious as there seems to be an never ending debate. I've never used Time-serts personally.

[mk1]

"get someone else to slowly pour the oil back in the engine as you drill the hole, the oil will bring out the swarf"

But fill your drill with oil!!!!!

I have helicoiled a good few Mini gearboxes in situ & have never had many problems getting the swarf out.

Whats a "Time-sert"?

[mk1]

Having had a google about I can now answer my own question.

A "Time-sert" is a solid thread repair insert.

I have not used these, but have made many similar inserts & can see no reason why they shouldn't be as good if not better than a helicoil.

[IAIN]

[quote="mk1"]"get someone else to slowly pour the oil back in the engine as you drill the hole, the oil will bring out the swarf"

But fill your drill with oil!!!!!

I did say 'slowly'

[Etienne B.]

Thanks guys,

Just to be sure : the thread we are trying to restore should be 5/8" - 11 UNC, shouldn't it ?

I am concerned by drilling/tapering the thread for the insert SQUARE with the casing - hard to achieve in situ ...
How did you do Mark ?

Those Time-sert are interesting, at least for their "collar" which forms a nice square surface for tightening the plug and the washer.
Am I wrong thinking that to fit one of those insert with Loctite might overcome the proofing difficulties that may be obtained with fitting the simpler Helicoil "unsquare" ? (sorry for this poor English - hope you understand me) ?

Made a few calls this morning : there is no way I can bought a Helicoil kit in UNC thread in France, unless I order (and wait for) a few hundreds coils, which is perfectly understandable but would seem slightly extravagant for my purpose ...
Do you know a good place to buy online those UNC solid inserts or eventually Helicoils in England or mainland Europe ??

Cheers,
Etienne

[Vegard]

I bought this as mentioned:

http://www.minimania.com/web/item/TOOL08/InvDetail.cfm

Very cheap and Minimania is always a pleasure dealing with when it comes to shipping, both price and time.

[Etienne B.]

Yes I saw this one, thank you Vegard, but the automatic shipping cost device of Minimania web site gave me a, say, "convincing" figure !!!! I should maybe drop them an email.
Minisport has a similar kit as well, slightly cheaper, although I am not sure it is a proper Helicoil.

Did you already fit a helicoil IN SITU in the past, Vegard ?

Edit : I forgot to mention that a parcel from america will be retained by the french customs until I pay the usual import tax, which adds to the timeframe.

[Ronnie]

Check these out! http://www.ebay.co.uk/sch/i.html?_nkw=+ ... &_osacat=0

PS Also try your local Wurth dealer or Snap on if you have them Wurth definitely do imperial Time Serts over here! The inserts for sale in the above link marked as 1.5 D are Std inserts which are 1.5 x the dia long but they are easy to cut to length!

[Etienne B.]

Thanks, I called Würth France, but there is no way I can buy Imperial Time Sert kits in a reasonable time frame - they only stock metric kits for the french market.
I only found Helicoil or Recoil kits in the UK yet.

[boxofbits]

Had the same problem recently but luckily I noticed that someone had fitted an oversize sump plug which was not even straight before I rebuilt the box, which was not in the car.

I opted to have a steel insert machined and fitted, which was then tapped to alllow fitment of the original sump plug.

[mk1]

If time is the issue. Why not find an oversized sump plug & drill / helicoil your gearbox for that new size.

I have only ever done this actual job once & I don't remember having any problems getting it in straight. It certainly didn't leak afterwards.

[251 ENG]

We use a combination of Time serts or Helicoils depending on how damaged the thread is . Normally use time sert on sump plug as it is normally done with engine in car . Put some grease on the drill and tap to collect the swarf . I have found that the imperial helicoils are not of the quality they used to be . Time serts are a good system , but the kits are expensive.

Where both systems fall down is if you have threaded hole that has previously been " butchered " and is greatly oversize or elongated . This is quite common on engine steady holes or the extra head stud hole near the water pump. It this case the engine will have to be stripped and the damage corrected on a milling machine . I have had these holes out to 3/4" UNF to clean them up and then make my own inserts and drill and tap back to STD size .

[Ronnie]

We use a combination of Time serts or Helicoils depending on how damaged the thread is . Normally use time sert on sump plug as it is normally done with engine in car . Put some grease on the drill and tap to collect the swarf . I have found that the imperial helicoils are not of the quality they used to be . Time serts are a good system , but the kits are expensive.

Where both systems fall down is if you have threaded hole that has previously been " butchered " and is greatly oversize or elongated . This is quite common on engine steady holes or the extra head stud hole near the water pump. It this case the engine will have to be stripped and the damage corrected on a milling machine . I have had these holes out to 3/4" UNF to clean them up and then make my own inserts and drill and tap back to STD size .

Do you use Armstrong inserts?

[251 ENG]

Use whatever supplier sends , normally come in clear plastic bag .