OIl drain plug

Started by tsumini, June 10, 2020, 07:17:34 PM

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tsumini

So i decide to change the oil mainly due to carboning of cylinders and darkened oil. Has less than 200 miles on rebuild and breakin.
Din't have 15/16 socket so tried a cresent wrench. Plug wouldn't budge so ran over to my son's and borroed a 15/16 socket. Tied it and still wouldn't budge and would't budge without a breaker bar. So i apused to think about this.
Plug is steel and gearbox is aluminum so probably corroded. (once had a aluminum hose connector that corroded on hose bib and needed a pipe wrench to get off). So I am half scared to break it loose and ruin the gearbox.
Any suggestions? Breaker bar and hope? Don't know of any other ideas. except that a would have impact wrench access.

tsumini

#1
Nevermind I got it with my torque wrench which has a longer arm 18" vs 9 " rachet arm. needed about 150 ft lbs.  I'll have to check the torque requiremenmts.

edit: hmmm... Minimania lists torque at 25 ft lb

94touring

That is scary and a lot of torque.  Changed my oil a couple days ago but all I do is tighten moderately by feel same as I'd do a spark plug.

tsumini


John Gervais

I cringe every time I tighten the drain plug.  I tighten it to approximately 'snug' and pray that the gearbox threads survive.  Years ago, I bought a helicoil & tap repair kit from MiniMania - just in case.  Thankfully, it's sitting in the box o'specialty tools and hasn't been used.

I always use a torque wrench for my spark plugs, tightening to 19-20 lbs/ft.

https://ngksparkplugs.com/en/resources/correctly-install-spark-plugs

I've never tightened spark plugs by 'feel'.
- Pave the Bay -

MiniDave

#5
I never use a torque wrench on either of those - the threads in the trans case are very robust and there's plenty of meat around it, as long as you don't over tighten the plug or cross thread it.

Same with the cast iron head, it's almost impossible to strip the threads in the head with a spark plug - by hand - of course you can strip anything with an air impact wrench!  ;D

The most important thing on spark plugs is to compress the washer fully first, then tighten the plug to it's final torque. I use a 3/8" ratchet - you can't get too crazy with torque with a short ratchet handle
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

gr8kornholio

I now have a baby torque wrench courtesy of father in laws tool box.  Odd little thing in a mountain of diesel pickup tools.
I am the GR8KORNHOLIO! Are you threatening me?

Saussie Aussie 1965 Australian MK1 Mini.
"Beavis" - 07 MY/MY MCS, B/MY Konig Daylites, JCW sideskirts, TSW springs, TSW lower rear control arms -- Exploring the country with new friends since 11/09.

tsumini

I was afraid of corroded threads but turned out to be just overtorqued. Steel plug, copper washer on aluminum is not a good combinatioin.  Almost inevitable that to seal will be overtorqued. Copper washer prob ought to be rubber coated or something. maybe one time use crush washer like spark plug.
Unfortunately there's enough oil leaks allready.

MiniDave

I've never seen corrosion on one of those drain plugs - you're right, dissimilar metals can cause galvanic corrosion - but I guess the frequency that it gets removed and the oil on it must keep it from doing that. I've seen a few that were cross threaded, but you have to really try to do that - or to overtighten it.

I use my 15/16 wrench and I get it plenty tight.

And you're also right about plenty of leaks from other places!   ;D
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

tsumini

Dave this was the first time I've had the plug out so was afraid the last install was a bare Gearbox with raw aluminum that had seen water or alkali clean. I know, worst case and conspiracy. Don't think 25 ftlbs will get it.

MiniDave

Well, you won't have a problem with it the next time! I guess you could always put a little anti-seize on the threads.....
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

tsumini