So on my birthday last week I take the day off and drive my recently aquired 1970 914 4 into the village.. I pull up to my favorite breakfast spot and my exhaust manafold is on fire.. The plug to the rear differential is missing and leaked oil onto the exhaust.. Hence fire.. Bring her into the shop n the threads are pretty beat up and my mechanic thinks that if he tries to tap in a bigger plug it'll crack the casing..
Anyone have any thoughts...

Thanks
Mark

Have a pic of the plug in question? I would just re-tap the threads and install the proper plug.

How about an expandable rubber drain plug?

"Rear differential"? Might wanna ask again, using terms with which we're familiar here in 914 land. AWD cars have rear diffs, BMWs have rear diffs, 914s don't. Pix would be nice.

The Cap'n

Cap'n
I appologize for my ignorance.. Ill take some photos and get back to you..

Bleyseng
do you think there is a chance of the case cracking when tapping new threads?

Racer
will the rubber plug keep it tight with the threads damaged and isn't there a possibility of it melting.

thanks
Mark

No, not if you do it right.
I see want to see a pic of what you are calling the rear diff....
Is it a 17mm drain or fill plug on the transmission or on the tail cover?
People strip the small bolt that holds the speedo drive in all the time. Easy to fix

if its the fill or drain plug your f'd replace the case.
seems strange though

Click to view attachment

Click to view attachment

Click to view attachment

Click to view attachment

These are the exploded diagrams of the transmission (tail shift) exterior. Your 914 has a "transaxle" so it includes both the gear stack and the differential and the lubricant is shared between both. Don't drive if you are loosing/low on oil.

So, before we speculate too much, where in the images above is it leaking from?

Items 17 and 18 are the fill and drain plugs.

Richard

Easier to replace the case....or get another one.

If it can be tapped, do that first.

Click to view attachment
Thanks for all the help, please bare with my ignorance, biologist.. but I'm learning
Here is a pic of the plug

-Mark

drill and tap it one size up, no sweat.

Even easier...Richard Castro or Dr Evil may have a used rear piece of the transmission to sell you...just replace that piece.

Rich

Would you have a used replacement available?

Unless I am missing something, that looks like a 914/4 tailshift end cover in which some creative surgery has been performed. If you notice in the parts diagram up above it shows that section as just having a smooth nipple shape. I am guessing that someone previously cut the end off for some reason and then attempted to thread and plug the hole.

My suggestion is to get a used replacement end cover. I think either Mike (Dr. Evil) or myself have what you need. I think Mike is closer to you so you might want to check with him first otherwise I can help.

Richard

Thanks Richard.. Just sent a pm to Mike, I'll let you know if he doesnt have one available
-Mark

If they can't help you, I have a number of those laying around.

The Cap'n

I'm sure I have one here. We can do the swap easily too, if you brought the gearbox (or the whole car) here.
We're about an hour from the New London Ferry.

You need more than the tail cone. That was caused by the large bolt that holds everything together on the pinion shaft, coming loose and boring its way through the cone with the speedo drive gear. I have a cone for ya, but that needs to come out, have the stack assessed to make sure no permanent damage was done, and put all back correctly. I wish I had better news for ya. I would be happy to do this for ya

Forget my last! Head in butt, just off of work. Wrong place for pinion bolt. Yes, you just need the cover. Not sure why that was the way it was. DAPO? You will need a new gasket. $5 from mikey914