VAG Tdi - Sump Plug

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Sun 11 Aug 2013 21:55
VAG Tdi - Sump Plug - brum

Original sump plug for my 1.9Tdi AHU engine had a replaceable copper washer . Sometime ago the VW dealer stopped stocking these washers and sold me a new sump bolt with a fixed aluminium washer (not very good). The washer sits in a narrow portion of the bolt under the head and so is not replaceable. I've bought a couple more bolts from GSF that have a fixed steel washer (even worse).

My question is - how do they get these washers on the bolt as they have a smaller inner diameter than the thread diameter?

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Sun 11 Aug 2013 23:00
VAG Tdi - Sump Plug - galileo

Original sump plug for my 1.9Tdi AHU engine had a replaceable copper washer . Sometime ago the VW dealer stopped stocking these washers and sold me a new sump bolt with a fixed aluminium washer (not very good). The washer sits in a narrow portion of the bolt under the head and so is not replaceable. I've bought a couple more bolts from GSF that have a fixed steel washer (even worse).

My question is - how do they get these washers on the bolt as they have a smaller inner diameter than the thread diameter?

Rolling the thread (rather than cutting it) increases the diameter of the peaks by displacing material from the bottom of the threads.

Can't offhand think of another means to do it?

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Sun 11 Aug 2013 23:45
VAG Tdi - Sump Plug - brum

Yup, I think you're right. Cunning germans....

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Mon 12 Aug 2013 09:54
VAG Tdi - Sump Plug - Quicksilver

I find the careful use of plumbers PTFE tape on the threads makes the seal oil tight without having to use a lot of force. Copper crushable washers are still the best.

Q.

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Mon 12 Aug 2013 14:29
VAG Tdi - Sump Plug - galileo

Yup, I think you're right. Cunning germans.

Not just Gemans, it's a process the likes of GKN and others have been using for over 40 years. Rolled threads are stronger than cut threads, mechanical properties are improved and there is no swarf produced.

Edited by galileo on 12/08/2013 at 14:29

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Mon 12 Aug 2013 17:06
VAG Tdi - Sump Plug - dadbif
Grip the washer in a vice and screw the sump plug out, reverse the process to fit a new washer, simples...
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Mon 12 Aug 2013 20:50
VAG Tdi - Sump Plug - Cyd

Threads are rolled. Almost all bolts, screws and threaded bar is made this way. Have been for decades.

PTFE tape should seal the thread effectively. Use Gas PTFE tape rather than ordinary (it's thicker and stronger and less likely to leave bits behind in your sump). Or Loctite thread sealer.

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Mon 12 Aug 2013 22:31
VAG Tdi - Sump Plug - focussed

Excuse me all you PTFE- thread-tape-people. A sump plug with a washer, copper crush washer, copper washer, or aluminium washer does not seal on the threads. It seals by compressing the washer between the face of the drain plug and the flat face of the drain hole. The reason that the washer will not come off the threads is not because of rolled threads, it's because the washer has been compressed and squashed and the hole in the washer has got smaller. Nothing wrong with aluminum sump plug washers, been using them for years by the hundreds, never had one leak or come loose.

Just saying.

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Tue 13 Aug 2013 00:16
VAG Tdi - Sump Plug - 659FBE

VAG engine sump plugs have a captive steel sealing washer from new. The washer is rendered completely captive by the thread rolling process. The steel washer does not spread appreciably in use as would a copper or other soft washer, provided the tightening torque specified by VAG is adhered to.

When tightened with a torque wrench as specified, these plugs seal very effectively - all of the parts are accurately machined. The plug/washer assembly may be re-used if undamaged (mine is leak free after 6 oil changes) and replacements are cheap.

Far too many people fail to observe the specified tightening procedure - the consequence is a leak at best, or stripped threads in the aluminium sump. VAG engines do not respond well to the attentions of cowboys.

659.

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