Oil seals for 120s

Bavaria 390 · March 14 2022, 22:58

How should the lower oil seals stand in the drive? With springs out or in?
Thanks!

Yngmar · March 14 2022, 23:19

Top option. Manual confirms: "When the seal rings have been installed, the springs in the rings should face away from each other".

If you look closely at the seals, you'll see why - they have a squeeze-out direction and a hold-against-pressure direction. The inner one needs to hold the oil in, the outer one the water out. So they both must be facing spring side towards their respective liquids to keep each one where it should be. That also means the outer (seawater) seal must have a stainless steel spring (the inner one is submerged in oil and it doesn't matter).

Bavaria 390 · March 15 2022, 08:27

Thanks!

Hotzenplotz · March 15 2022, 10:53

Hi,
can you look at the seals if there is a designation on it?
Need to change the seals, too but haven't dissassembled yet.
They are nearly 40€ per pce at Volvo, seems they are made of gold...
It's not about the money, it's just a hobby not to support this price policy...

thanks
HP

Bavaria 390 · March 15 2022, 11:09

Hi! The spring should be stainless, otherwise it is a regular oil seal. The spring can be replaced with a rubber ring.

geoff · March 15 2022, 11:49

If you buy Viton seals from simply bearings they all have stainless springs. The shaft on a 120s will be getting old by now and probably grooved .The original seals are 9mm wide so the total is 18mm, 10 years ago I replaced the 2 seals with 3 6mm wide Viton seals in the same space ,the seal lips fall in a new spot and there are 3,one keeps oil in and 2 keep water out. The mod has stood the test of time and is much cheaper than speedi sleave. Geoff

Hotzenplotz · March 15 2022, 14:03

thanks for the pics and the advise, this is very helpful.
regarding the dimensions: it isn't metric, it's inch (1.25x2x0.25) - right?
have a nice day
HP

SYJetzt · March 15 2022, 15:25

Quote10 years ago I replaced the 2 seals with 3 6mm wide Viton seals in the same space

Great hint and a lot of ingenuity

Bavaria 390 · March 15 2022, 20:58

Quote from: Hotzenplotz on March 15 2022, 14:03
thanks for the pics and the advise, this is very helpful.
regarding the dimensions: it isn't metric, it's inch (1.25x2x0.25) - right?
have a nice day
HP

Yes, I think so too.

Bavaria 390 · March 15 2022, 21:01

Quote from: geoff on March 15 2022, 11:49
If you buy Viton seals from simply bearings they all have stainless springs. The shaft on a 120s will be getting old by now and probably grooved .The original seals are 9mm wide so the total is 18mm, 10 years ago I replaced the 2 seals with 3 6mm wide Viton seals in the same space ,the seal lips fall in a new spot and there are 3,one keeps oil in and 2 keep water out. The mod has stood the test of time and is much cheaper than speedi sleave. Geoff

I squandered the lid housing and moved the oil seals 3 mm closer to the propeller.