changing the oil

[Jazzman]

I was going to chage the oil of the car today and the plug is so tight I could not move it!

The drain plug is having a square head. Before I used a normal spanner but it is so tight the spanner started damaging the head.

Is there a special tool for this kind of square heads?

thanks guys!

PS - I have just covered the plug in WD40... lets see if it lubricates a bit.

[CharlieB]

Moss do a special spanner (7/16" square). I find a 1/2" AF 12 point socket usually works.

[npanne]

If the square head gets really bad (like mine did), file it square again, then hammer the drive end of a socket onto it. I used a hex socket, then used a regular socker to turn that.

[Clive]

Tapping the the plug with a small light hammer may help. Not too hard though.
It is possible to get magnetic plugs with a hex head, I think they are used on our gearboxes. Rather easier.

Clive

[heraldcoupe]

If the drain plug has previously been tightened by a gorilla, a Stilson wrench should undo it, failing all else,
Cheers,
Bill.

[99176]

Buy a replacement BEFORE butchering the existing.
Ask for a hex replacement complete with magnet.

[Jazzman]

I am going to try... I will keep you updated. I

t freeks me out to push that hard while under the car. Even though I have stands... I will try to access the bolt from above.

[JohnD]

Jazz,
Freek away - you need to push some wheels under the car while you are under there. Two in a pile, if the car is high enough, but one each side will leave enough room for you to breath if the worst happens.  Best have someone standing by.

I'm a fan of heat for loosening parts - when heated, a bolt expands less than a nut, or in this case the threaded insert brazed into the sump.   You can't get it too hot, as the oil will conduct heat away rather well, but a blast with a blow torch may help.  Mind your fingers!

John

[CharlieB]

JohnD wrote:

when heated, a bolt expands less than a nut

Not if they're both made of the same material, they'll both expand the same.
I think it helps if you can get more heat into the nut/boss

[mark spit]

I recall from a science lesson many moons ago, a ring supporting a ball, both of the same material being heated and the ring expands more so the ball drops through, same as a nut/bolt effectively.

A mate advised of something similar to remove bearing races stuck on shafts or in hubs,  run a bead of weld round the race, if it's on a shaft it'll expand moe than the shaft and come off, if it's internal in a hub, it'll cool down quicker and shrink more than it was and fall out.  Commonly done in the factory where he's a fitter..

Yours
Mark

[CharlieB]

The amount something expands depends on the coefficient of thermal expansion of the material & the temperature rise, the shape makes no difference.
Think about it what if there was another ring outside your ring?
Obviously if you put more heat into one part than the other then thats a different story.

[Clive]

Aha, being a science teaher I have demo'd the very expt MANY times. Its just the ball you heat. A sort of now it fits, now it doesn't to amazed gasps from the audience. I can make that last an hour by the time I've told a few stories about when I was a lad...................................

[JohnD]

Thank you, clifty, nothing like experience over theory.
Heat the ball and the ring falls through.
Or the bolt comes loose.

Same with cooling - there is a well known product, Loctite Freeze & Release, that does the same job 'in reverse'': http://www.ferret.com.au/c/Loctite-Henkel-Australia/Loctite-presents-new-Freeze-and-Release-lubricant-n672370

I don't find it works as well as BIG ROARING FLAME!!!

John

[Clive]

Flames are Fun ;D
Just ask any kid what they like in a lesson. BUNSEN BUNSEN is the chant you get as a reply.
And then theres the teachers. I won't go into detail about the melted fireblanket, the hardwood table with an inch deep burn or the melted sheet steel......

[npanne]

cliftyhanger wrote:

Flames are Fun ;D
Just ask any kid what they like in a lesson. BUNSEN BUNSEN is the chant you get as a reply.
And then theres the teachers. I won't go into detail about the melted fireblanket, the hardwood table with an inch deep burn or the melted sheet steel......

I recollect the joy of discovering that a heated coin would "float" on the smoke that it produced when burning the varnish off a new science lab bench. This could then be flicked around (á la primitive air hockey), leaving burnt tracks behind it.

Sorry !   ;D

[CharlieB]

JohnD wrote:

Thank you, clifty, nothing like experience over theory.

Experience & theory are in agreement, you have to heat one part more than the other which was my original point.

[bodders1]

cliftyhanger wrote:

Flames are Fun ;D
Just ask any kid what they like in a lesson. BUNSEN BUNSEN is the chant you get as a reply.
And then theres the teachers. I won't go into detail about the melted fireblanket, the hardwood table with an inch deep burn or the melted sheet steel......

At our school, we didn't bother with the bunsen burner - we just lit the gas taps in the physics lab.  If the gas pressure was high enough, you could get a 3 foot long flame straight across the desk  ;D  I lost most of the hair on my left arm as a result  :-/

[JET]

Some of you guys are SERIOUS PYROMANIACS.

[JohnD]

But charlie, clifty's experience (and practice) was that he played the flame on the BALL.  If that heated the ball more than the ring, then according your physics the ring would stick tighter.

John

[Burnerboy]

Flames ARE fun! (don't ask why they call me Burnerboy:))

A couple of days before the last La Carrera I was helping my mate to change a crank end oil seal on his Nova. Could we shift the crank pulley nut? Not a chance. Tried heat, long breaker bars on the socket, impact wrenches, everything.
Then another mate gave us some of the freeze spray stuff - absolute magic! Plus you do not run the risk of setting anything on fire....

[CharlieB]

JohnD wrote:

But charlie, clifty's experience (and practice) was that he played the flame on the BALL.  If that heated the ball more than the ring, then according your physics the ring would stick tighter.
John

John, you're not seriously suggesting you heat the ball & it shrinks & falls through the ring!!

No, Clifty please correct me but I assume when cold the ball fits through the ring ("now it fits") then you heat the ball & "now it doesn't" que gasps from kids.
If I'm wrong I better go & join Clifty's class!

The only exception to the expands when you heat it rule that I'm aware of is water that has the unique property of expanding when it freezes to form ice, something to do with crystal structure?

[JohnD]

No, Charlie, the ball sits in the ring when cold, but falls through when they are heated. The ring expands more than the ball.
Of course, when exposed to the same heat source, a solid metal ball will heat up much more slowly than a thin ring around it - surface area and volume - so the ring probably does get hotter than the ball does, which begs the question rather!

But as I mentioned above, intense cold can have the same effect - hence the nut-shifter spray I mentioned above.

John

[CharlieB]

cliftyhanger wrote:

Its just the ball you heat.

I'm obviously not going to convince you John, so I won't try any more but I suggest you google "ball & ring experiment"

[phil866]

The only way to fit a new ring gear is to heat it up and drop it onto the cold flywheel!  Exhaust fitters use oxy acetylene to heat off bolts and sections of exhaust. The expansion and contraction breaks all sorts of stuck seals. Adding energy excites the molecules which then need more room to move around, so the metal gets less dense (and softer) by becoming larger but remaining the same weight.....or something...... Be careful how hot you get the thread in the sump pan as it is only braised in place.

[JohnD]

http://www.youtube.com/watch?v=mMeqxBFFbg8

I can't believe it - none of the kids heated BOTH ring & ball!
I would have done!

John