How to break fill and drain tranny nuts loose

[Bilito]

I went to change the tranny oil in My 97 Z3 5 speed and I cannot break the drain and fill nuts loose, any thoughts????

[testify]

PB blaster and a long half inch breaker bar.

[Vintage42]

The plugs are tapered. Don't turn the wrong way to break them loose, or they can split their base.

[raubritter]

And when you're putting them back on... I know there's a torque spec but I cracked my original diff rear case using a torque wrench to the correct spec. Since then, with oil, diff, and transmission plugs I use a short ratchet and tighten until hand tight, then a bit more. Diff and trans cases are aluminum so I'm especially careful.

[Bilito]

They are righty tighty and lefty loosey right

[raubritter]

Yes, they are normal left-to-loosen. I do know I'm not the only one to have cracked a case using the 'correct' spec, so that's why I mentioned it.

[raubritter]

By the way, the first time I took the transmission plugs out they were on really tight and I had to use a breaker bar...

[328 Power 04]

Yes, agreed, and use thread sealant.

[Mr Bingley]

Whatever else you do, loosen the fill plug first--not the drain.

[Bilito]

I am using a 1/2 breaker bar and cannot get them loose, think I will need to get an extension for that. It's a combination of insufficient room under the car while on jack stands and fear of knocking the car off the jack stands. I have never seen plugs on this tight before, could be they have never been off.

[testify]

If theres a Harbor Freiggt near you, you can pick up a long half inch breaker very cheap. Pick up some 6 ton jack stands too. I've got 2 feet of room under my car, not to mention I feel much safer with the larger foot print of the larger stands.

[Bilito]

Went to the local Harbor freight they are pout of the 20 inch 11.99 1/2 inch breaker bars until their truck comes tomorrow

[Vintage42]

They are righty tighty and lefty loosey right

Just saying, in trying to loosen regular stuck bolts, I have knocked them both ways to free any play in the corrosion. Which won't work with tapered bolts.

[bcoffin]

Hit them with pb blaster the night before you do the job. Then eat your wheaties for breakfast and have at it.

I find it helpful to position my body to where I am PULLING the breaker bar to loosen the bolt instead of pushing. I find, while under the car laying on my back, I can pull with much more force than I can push.

[Bilito]

Good tip, thanks

[ixlr08]

I just did mine, I had to put a 1-1/2 ft pipe extension on my breaker bar to get them loose. Fill plug was easier than the drain plug, partially because I was twisting hard enough on the drain plug that was causing car to shift on supports and I didn't want to pull any harder and it was also an awkward position.

[ProductUser]

I've used a small hydraulic jack to apply force to the breaker bar in such cases. I used this technique to break loose the 36mm rear drum nut on my VW bugs. This technique may not apply in this instance.

[Bilito]

Wonder if heat would help, I have a heat gun used for peeling paint

[raubritter]

I was hoping to hear that you'd gotten them loose... Frustrating when stuff like this happens.

Is there any way you could get access to a drive-on lift for a few minutes? That way you'd have plenty of room and not worry about the car falling off jack stands... All you'd need is to break them loose, then you could do the fluid change back in your garage. I wonder if you showed up at an auto shop and (if they wouldn't let you use a lift) asked them if you could drive over one of those things where the car stays at ground level and there's a hole underneath that you can work from?

[ECSTuning]

Whatever else you do, loosen the fill plug first--not the drain.

This is what I came here to say! +10000

-James

[SunzOut]

FYI - New plugs are a different design with seal built in.

[rf900rkw]

Sorry, no. The diff plugs now have a captive o-ring rather than a washer. The trans plugs are still metric taper pipe. You can not change the type without remachining the case.

The problem the OP is experiencing is common. It is caused by the previous person putting the plugs back in "good-n-tight". Taper pipe threads work by bending the metal The metal yields to the direction of rotation, mating and interlocking. Think of it like a bottle brush. You can insert and turn the brush fairly easily. But try to reverse rotation once inserted. The end result, the break loose torque can easily be five to ten times the installation torque.

The answer? Torque. Lots of it. prenetrating oils will only make your wrench slip easier. Heat might help, but will likely make it worse. Get a good socket and breaker bar, and about three feet of cheater pipe. It's the only way. And don't put them back in as tight.

[LannVouivre]

With the car on the stands, shake the car firmly to make sure it's properly supported. Don't be stupid with it, but make sure that you know what you're doing under the car won't unsettle it. If needed, get a level headed person to keep watch. Do not get a panicky imbecile out there with you.

[Bilito]

Wow I never expected this thread to go this far, thanks for all the info, I now have everything I need including an 18 inch pipe extension for the breaker bar, will try to under there tomorrow and see how it goes

[gmushial]

Hit them with pb blaster the night before you do the job. Then eat your wheaties for breakfast and have at it.

I find it helpful to position my body to where I am PULLING the breaker bar to loosen the bolt instead of pushing. I find, while under the car laying on my back, I can pull with much more force than I can push.

This pushing and pulling and left and right is the wrong way to talk about it, because it is all orientation dependent :-( the descriptions need to be: as viewed down the normal vector toward the plug, the plug is rotated anti-clockwise to loosen, and clockwise to tighten.

The other point it: in high torque situation, you never just pull on the wrench or breaker bar, in that in doing such much of the force is going into a) trying to knock the car off the stands, and b) trying to round the head of the bolt/plug enough so that the wrench can slip off (and if you're lucky, only bloodying your knuckles). The correct way in such situation is: one hand on the head of the wrench at the plug head (in this case) and one on the end of the breaker bar, forcing the action to be rotational, and directed at removing the bolt/nut/plug.