gear oil seeping past the drain plug

[thegarzacomplex]

Hi Everyone, I recently drained and refilled the gear box, but after tightening the drain plug beyond what i was comfortable with, it still leaks - drip, drip, drip.
I did reuse the copper washer, only because i could not locate new ones from any of the well known parts suppliers.

Any suggestions?

thx, scott

'89 Alfa grad
'98 Ford Contour SVT
'02 Mercury Mountaineer

[ghnl]

The copper washer becomes work-hardened over time (repeated use) and thus doesn't conform to small irregularities allowing leaks. Try annealing the washer (or buy a new one). Link to instructions: how to anneal copper washers

[Geezer]

I wouldn't call the rough cast surface that the copper washer is expected to seal against as having small irregularities. A copper washer should seal against a smooth machined surface.

It's too bad the engineers at Alfa didn't pay attention to the details when designing the transmission case. A simple machining step to to give the drain plug a clean surface to seal upon or a simple counter bore around the opening to provide for an O-ring would have been all it would take. The next time my trans is out the case is going to the machine shop to do what Alfa should have done years ago.

What I do now is put a small bead of silicone sealer in the cervace between fillet of the drain plug and the ID of the copper washer to seal up the drain & fill plugs. Perhaps an O-ring would also work or possibly a washer that has a built in sealing ring in the ID of the washer.

[aldo]

Try some teflon tape on the threads.

[msiert]

Mine weeps too and like you said I wouldn't dare tighten it anymore either.............IMO it normal and nothing to worry about past getting a new copper washer.

[msiert]

Mine weeps too and like you said I wouldn't dare tighten it anymore either.............IMO it normal and nothing to worry about past getting a new copper washer.

[Alfar7]

Aluminum Washer!

[msiert]

Quote:

Originally Posted by Alfar7 Aluminum Washer!

[Gary Knox]

I used a new aluminum washer when I drained and refilled my transmission and differential cases with no leakage upon tightening to torque spec. I used synthetic lube when refilling as well.

Gary Knox
West Chester, PA
'91 SV, 19.8 K miles

[WopJob]

[quote=Gary Knox;479173]I used a new aluminum washer when I drained and refilled my transmission and differential cases with no leakage upon tightening to torque spec. I used synthetic lube when refilling as well.

Speaking of lube. I'm about to change the gearbox lube. I just changed the diff with valvoline 75-90 synt. reading the specs on this oil it seems like it will also work on the gearbox too. Yes I know that spirax HD 80-90 (I have this in now) is the preferred oil for the trans but shifting the trans is really awfyll in this cold weather. I'm thinking that the "75" will give me bettere cold weather shifting. Thoughts?

[Bill]

[quote=WopJob;479210]

Quote:

Originally Posted by Gary Knox I used a new aluminum washer when I drained and refilled my transmission and .... Thoughts?

[WopJob]

[quote=Bill;479240]

Quote:

Originally Posted by WopJob Tony, Thats one heck of a nice Flounder in your avitar!!! (or is that a small Halibut? ).

[Zunige]

Quote:

Originally Posted by WopJob Speaking of lube. I'm about to change the gearbox lube. I just changed the diff with valvoline 75-90 synt. reading the specs on this oil it seems like it will also work on the gearbox too. Yes I know that spirax HD 80-90 (I have this in now) is the preferred oil for the trans but shifting the trans is really awfyll in this cold weather. I'm thinking that the "75" will give me bettere cold weather shifting. Thoughts?

[WopJob]

Thanks Enrique. I haven't seen Valvoline 75-90 mentioned here for the tranny. I have no particular allegiance to Valvoline or Redline. Just that I can get Valvoline easier at my NAPA. If I don't get any negative feedback about the Valvoline I'll change it this week end. I was wondering what Alfa used at the factory. As you might know I owned an 86 new from the factory and drove it year aroung in NJ. never really had a problem.

[papajam]

I would not use the Valvoline 75-90 in an Alfa gearbox. Not because it's Valvoline but because it's a hypoid gear oil with EP (Extreme Pressure) additives. These additives make the oil too slippery for the syncros to work properly. There are numerous threads on what oil works well with a preference, I think, toward the Redline (although I don't know which kind since I've always used straight 50 weight engine oil in an Alfa gearbox).