Gearbox Dip Stick length

[Palikary]

i have a 1983 Beta Coupe 2000 with Manual Transmission. I changed the gear oil and was expecting to only use around 1.8L of gear oil. I wasn't getting any reading on the dip stick at 1.8L. It took around 2.5L to get it to show on the max line.

I want to confirm that my dip stick length is accurate as the rubber stopper may have moved or not in its right position.

Its 11cm from the flat rubber to the Max line and 11.5cm to the Min line. Is this correct?

[Nigel]

You're correct that it should take 1.8 litres.
If it took 2.5, it's probably overfilled, question is why?

Is it possible you misjudged the quantity?
Did you fill via the dipstick hole? That's the only spot available.
Your measurements match a dipstick I have here.

I would check it again after a drive, after letting it settle.

Nigel

[Palikary]

Yes, it was filled thru the dip stick hole.

I have driven it a few times since and let it settle on flat ground and its showing correctly right upto to the max line with the 2.5L.
Is the 1.8L meant to be upto the max line or min?
I definitely used 2.5L as I bought a 5L bottle of the gear oil and there is 2.5L showing left.
When I drained the oil I opened 2 drain plugs. One below and the one of the side of the gearbox to get both chambers. Is that correct process?

I'm tempted to drain it again and measure a new batch of 1.8L and don't go off the dip stick reading this time.
The only reason why I'm checking this is I'm getting a whining noise from the gear box when I am off the throttle so it could be from the overfill so I can rule that out before looking at anything else.