Drain plug

[Robbie693]

My gearbox is leaking from the drain plug, I've tried tightening it as much as I dare but it still drips...

I'm using a big adjustable spanner which is not ideal, can I get a socket to fit the square plug so I can use the torque wrench? Tried searching the net but found nothing...

Alternatively, I thought about putting some RTV on the threads of the plug. Good idea?

[ncm]

Have you considered using PTFE tape ? Available in all the DIY sheds!
Cheers, Brian.

[CBUEB1771]

Sockets for square-headed pipe plugs are quite common. Generally they are supplied in eight-point configuration as seen at Snap On's web site (specialty sockets section). I prefer an old fashioned pipe thread sealant such as RectorSeal. My gearbox drain and fill plugs remain dry as a bone using this sealant. (Let's see how many clever responses we get with the more colorful puns around RectorSeal.) I find PTFE tape to be less reliable than the emulsion type sealants.

[Robbie693]

Russ,

I've got some Loctite copper RTV, is this an emulsion type sealant ?(forgive my ignorance)

[CBUEB1771]

Robbie,
I am not sure about the Loctite product you have. The emulsion type pipe thread sealants are an extremely fine powder suspended in a mixture of alcohol and perhaps a light oil. In recent years many of the manufacturers have used a teflon powder. I bet some fine clays were used in years gone by. If your Loctite container indicates the product can be used to seal pipe threads then go ahead. I am a little doubtful because Loctite makes teflon emulsion sealers specifically for pipe threads. Loctite 545, 565 and 567 are examples. RTV materials are better used to augment gaskets where the joining surfaces may have minor defects.

[GrUmPyBoDgEr]

Don't go too mad with the tightening bit.
The plug has a tapered thread, you don'twant to put a split in the casing.
The thread sealants mentioned are a good idea. You will have to drain the gearbox & ensure that the threads are degreased (free of oil). Most modern sealants cannot cope with oil contaminated threads; the degreasing agents being deleted due to "health & safety".
When I was putting my car back together I used plumbers PTFE tape, which you can buy from DIY stores. It worked well for me.
John

[Robbie693]

Ok, thanks all for the replys. Thread sealant is the way to go then.

Cheers

[GrUmPyBoDgEr]

Have just read through the thread again & if you use a Loctite sealant I can recomend either 542 or 510 or 515.
All are recomended for such automotive applications and are used by the industry.
Good luck.
John

[CBUEB1771]

Have just read through the thread again & if you use a Loctite sealant I can recomend either 542 or 510 or 515.
All are recomended for such automotive applications and are used by the industry.
Good luck.
John

I don't mean to be difficult but Loctite 510 and 515 are intended to be used as an alternative to gaskets where machined flanges mate. Loctite 542 is a reasonable choice but 565 and 567 are specifically intended for tapered pipe threads. Loctite's web site is very useful for determining the correct product for an application.

[GrUmPyBoDgEr]

Thanks Russ,
I bow to your superior knowledge
I seem to remember that the ones you mention tend to lock the thread a bit, possibly causing removal difficulties. (It's long time ago though).
Cheers
John

[CBUEB1771]

I seem to remember that the ones you mention tend to lock the thread a bit, possibly causing removal difficulties. (It's long time ago though).
Cheers
John

John,
You raise a very good point. Some Loctite products can be too much of a good thing at disassembly time. Their 565 PST pipe thread sealer is listed as having "controlled strength". This is odd language to describe a sealant that does not set up too hard and thereby eases disassembly.

[iain.hamlton]

Any idea why it's leaking? Damaged plug, or damaged threads in the case? These things usually seal very well. Might be worth a close look, and possibly changing the plug before doing anything too drastic. After all, it's something you will remove again fairly soon.

best regards, iain

[Robbie693]

Hi Iain,

I don't know why it was leaking, I've changed the oil now and the plug looked fine. I sealed the threads and the plug screwed back in smoothly so I think there is no damage there.

I think it's ok now (time will tell).

Actually the last Plus 2 I had started leaking after I changed the oil too. I think I used Hylomar to fix that one. Can't remember if it worked though..