bigwinged sump issues

[PAUL V]

Bit of long shot but wondering if someone has noticed this.

On my Big wing sump, some of the flange bolt holes where the speedo drive cover bolts on is open to the sump oil, has anyone ever noticed this ?

I did on assembly and thought it was strange but think i put some RTV on the threads.

The issue is only after 400 miles i am getting what i think it engine oil into the speedo cable !

I have yet to take the speedo cover off to prove this, but i cannot see any other reason how oil can find its way up into the speedo

[VADreamer]

I noticed the lower two bolts on my big wing sump now penetrate into the sump wing. But, I don't see how an appreciable amount of motor oil could seep into the speedo gear housing. I don't have mine on the road yet, but, looking at my assembly pics, there are two possibilities, however unlikely, that I see.
1. Overfilled front diff.
2. The cross shaft tube inside the sump is cracked or missing.
Again, not likely, but all I got.
cheers,
Boyd

[PAUL V]

I noticed the lower two bolts on my big wing sump now penetrate into the sump wing. But, I don't see how an appreciable amount of motor oil could seep into the speedo gear housing. I don't have mine on the road yet, but, looking at my assembly pics, there are two possibilities, however unlikely, that I see.
1. Overfilled front diff.
2. The cross shaft tube inside the sump is cracked or missing.
Again, not likely, but all I got.
cheers,
Boyd

Thanks for taking the time to reply, your response did help me as i was going down the rabbit hole of the sump being the issue.

What i had left out was the initial problem was thought to be the diff breather, but on sticking a camera up i could see the 3mm hole in the side of the Quaife diff case ( this was new along with the diff all supplied by and all assembled by Bara).

Now checking the diff oil level which was not overfilled i thought i would put some air into the filler hole and see if it came out of the speedo drive, sure enough it came out of the centre, BUT the pressure was building and the key point i could not hear any air coming from the breather hole !

Dropped the front diff inspection plate off and to my surprise the there was no hole in the diff case for the breather. I managed to get a 90 degree air drill in from the outside and drill the existing hole thinking that would do, but no, it took me 2 more attempts and i managed to break through into the case in the right place.

Bit pissed about it all if i am honest, it it lucky that i took the clocks out to fix the Tacho that i found the oil, if i had left it would have gotten into a big mess under the dash / pedal box area .

[VADreamer]

Happy you figured it out. Had a similar experience with a old motorcycle.
cheers,
Boyd