411 gearbox oil leak...

[Dubs]

Hi again folks...looks like I need to call on the collective wisdom of STF again..

After I moved the car out the workshop I was faced with a small puddle of gearbox oil....a quick glance underneath showed it to be coming from the front so I assumed it was going to be the selector shaft seal....however on closer inspection it looks to be coming from higher up than that..

I whipped the cover of under the rear seat and this is what I am looking at..



It looks to be coming from the casing behind the bracket. I seem to remember reading that 411 boxes have a breather hole in the front of the nose cone, would that be about where it is? And if so, what would cause it to leak oil other than being over filled?

Strangely, if you go for a run and then park up and have a look it doesnt appear to leak, if you just leave the car stationary and run the car for about ten mins while you try and fix the running problems it does leak..

Anyone got any ideas?

Cheers in advance

[raygreenwood]

As you noted....other than overfilling...not much can cause "excessive" case pressure in the 004 four speed.

But there are a ferw things to think about.

1. Have you been hearing any excessive noise from the transmission? The reason I ask is that if the counter shaft bearings are going (and they all will sonner orlater...they and their shaft are replaceable wear items)....it increases the oil flow through the counter gear which can overflood the tail cone area. Sadly....if the counter gear had better oil flow the excessive wear may not even happen.

2. If the oil slinger shield on the mainshaft ballbearing has cracked or is wearing loose it also can overflood the tail cone housing where the vent is.

3. It may not be the vent. very close to the vent hole is a plastic plug that is the shift linkage vertical pivot shaft housing. It can crack with age and be a leak point.

4. And you need to check this.....it may be leaking from the screw in main shaft plug threads themselves. If so..it means that the special lock nut on the end of the main shaft may be coming loose. It will knock against and turn outward....the plug. When it finally goes tyo far...the threaded stud on the end of the mainshaft will almost instantly drill a hole in the cap...and cause the shaft to pop backward out of the driveline splines....it will stop your forward progress dead and scare the hell out of you!
been there...so check it!
Ray

[Dubs]

Cheers Ray.

I Had the chance to look further into it today. it was indeed running from the breather hole, so I crawled underneath and took the filler plug out and a good half to three quarters of a litre ran out up my arm and onto the floor! I guess the box must have been filled while it was on its side out the car or something.

with it all cleaned up I ran it up and the problem seems to have gone so fingers crossed, that's all it was.

The box doesn't make any excessive noise and shifts smoothly so It's looking good for now.