damaged transmission drain plug out, fluid changed. Wow!

[DaveMcKenz]

Hi guys,
I wanted to thank the forum for all the good advice. My drain plug was pretty buggered, see pic. The fluid was of unknown vintage, and type. I went with several of the suggestions for removing the plug: remove fill plug first, lapping compound, shop rag, pounded in plug tool, support with jack, and use a cheater bar. Came out, and so did some nasty fluid. I refilled my 84 3.2 915 with Kendall, 3+ quarts.
The shifting is vastly improved. Other oils might have been great too, considering what was in there.
Anyway, thanks,
Dave

[DRACO A5OG]

Congrats, that bolt sure is ugly :-o

[Bob Kontak]

Good job.

I am thinking that plug is going into the Ripley's museum.

Nothing like the feeling when that bad boy breaks free. It's like, "Dear God, thank you for your mercy. I will never let this happen again".

[DaveMcKenz]

Exactly!!

Good job.



I am thinking that plug is going into the Ripley's museum.



Nothing like the feeling when that bad boy breaks free. It's like, "Dear God, thank you for your mercy. I will never let this happen again".

[The cap'n]

"Nasty" fluid? Gear oil is "nasty" right out of the container! The big story is right on the drain plug magnet ...............

The Cap'n

[TheSt|G]

Originally Posted by Bob Kontak

Good job.

I am thinking that plug is going into the Ripley's museum.

Nothing like the feeling when that bad boy breaks free. It's like, "Dear God, thank you for your mercy. I will never let this happen again".

We all have had that moment.

I treated myself to a full new of new drain plugs when I swapped the trans/diff and engine oil for the first time on the 911.

[douglas bray]

Nasty is the smell of LSDA (limited slip additive). It will stay with you for a week if you get a drop on your hand.

[DaveMcKenz]

It does smell bad. For my old fluid it was dark like coffee. The new oil was much more clear. The magnet looked bare but stained a rag when I wiped it off.
Dave

[Jesse16]

Amazing that the plugs can be so tight. Hoping you put the new one on with with more "normal" removable in the future torque. Seems anyone I have who does work on any car I've ever owned tightens bolts much tighter than I do. You might do a second drain and refill to clear the last vestiges of old oil.

[The cap'n]

The drain and fill plugs have a tapered thread. There is NO NEED to tighten them to the degree we often see. "Good and snug" works fine, and no sealant is required. I prefer the external hex plugs over the inhex design. Others may disagree with that, but I can see no reason to favor the latter.

The Cap'n

[KTL]

For some reason Porsche decided to use tapered threads in the 915 plugs. So when you tighten it, it seems nice and snug. Then when you go to loosen it, snug become gorilla tight. I hate tapered threads........

If you can find one, the "outie" style of plug that you use a regular wrench on is easier to put a wrench on. But those are pretty rare. I would suggest getting an aftermarket plug with a smaller, sturdier inhex that is less prone to stripping. The size is M24 x 1.5 tapered thread

Metric Pipe Plugs

Ooops cap'n beat me to it. Sorry for the redundant info

[zippy_gg]

Originally Posted by Jesse16

You might do a second drain and refill to clear the last vestiges of old oil.

+1 on that.

[obscene]

I did mine last night too and forgot how awful the smell is!

[DaveMcKenz]

I was also thinking of a repeat drain and refill, maybe next Summer. I actually used a torque wrench at 17 foot-pounds to get a feel for tightness. Copper antiseize also.
Thanks,
Dave

[Bill Douglas]

Originally Posted by DaveMcKenz

Copper antiseize also.
Thanks,
Dave

That's cheating Dave, just too sensible (and thanks, I'll do that myself next time).

[TimT]

The drain and fill plugs have a tapered thread. There is NO NEED to tighten them to the degree we often see. "Good and snug" works fine, and no sealant is required. I prefer the external hex plugs over the inhex design. Others may disagree with that, but I can see no reason to favor the latter.

+1 and +1 to KTL

This picture could be used in a physics class when Vectors are discussed, it demonstrates handedness and the right hand rule..





A few things are obvious, the amount of force applied by the internal hex was great enough to distort the drain plug metal and allow the bit to cam out..

right hand rule for torque



Another thing that is happening when trying to loosen a previously over tightened internal hex plug... is that the force you apply to loosen the plug is also trying to expand the plug...

This is where it gets really circular, you need more force to turn the plug, the additional force tries to expand the plug more which will require more force to turn..

Out comes a cheater, and all of a sudden you have a plug that looks like the one pictured..

Just check how little meat is between the the surface the hex bears on and the threads..

The fill plug I'd swap out for a external hex plug... the drain... I'd still use internal hex...I'd be worried about catching that plug on something...

[DaveMcKenz]

Thanks guys. I bought the drain plug tool from Pelican. I ground off the rounded end until it was completely flat. I broke the burs but that was all. If you look inside the damaged plug, there is still a hex pattern. I shoved it in with lapping compound in a rad, and lifted the wrench and the transmission with a jack. Only then did I try to unscrew it. Thanks goodness it work.
Dave

[The cap'n]

Originally Posted by KTL

For some reason Porsche decided to use tapered threads in the 915 plugs. So when you tighten it, it seems nice and snug. Then when you go to loosen it, snug become gorilla tight. I hate tapered threads........

If you can find one, the "outie" style of plug that you use a regular wrench on is easier to put a wrench on. But those are pretty rare. I would suggest getting an aftermarket plug with a smaller, sturdier inhex that is less prone to stripping. The size is M24 x 1.5 tapered thread

Metric Pipe Plugs

Ooops cap'n beat me to it. Sorry for the redundant info

VW and Porsche (Audis, too)have used tapered drain and fill plugs on manual transaxles since the very beginning, and 356/912 and pre-40 horse VWs used 'em on the engine drain plugs, too.

The Cap'n