75w90 or 75w140 gear oil in lower unit?

[USA_boater]

2004 VP SX...I figure I'll change the gear oil on this first winterization of this boat since I've got it. The PO changed the oil before it was stored in 2013 and then it was never used again until I bought it in 2018. Before I took it out this summer I did check the level but decided to run the 5yr old "new" oil until I put her away for the year. Now its that time and I wondered if since the boat is run only in warm whether, and is an older boat, if anyone thought 75w140 would be okay? The plan is regardless to try and find some that doesn't spec for limited slip full-fills. I've heard the OEM VP oil doens't have any LS additive in it and that if you use anything else you should try and avoid the LS additive?

 

[Horigan]

Manual calls for 75W90. I would run either Volvo or their suggested alternative Mobil1.

 

[Scott Danforth]

2004 VP SX...I figure I'll change the gear oil on this first winterization of this boat since I've got it. The PO changed the oil before it was stored in 2013 and then it was never used again until I bought it in 2018. Before I took it out this summer I did check the level but decided to run the 5yr old "new" oil until I put her away for the year. Now its that time and I wondered if since the boat is run only in warm whether, and is an older boat, if anyone thought 75w140 would be okay? The plan is regardless to try and find some that doesn't spec for limited slip full-fills. I've heard the OEM VP oil doens't have any LS additive in it and that if you use anything else you should try and avoid the LS additive?

use synthetic marine gear lube NOT automotive lube.

I personally run Amsoil Marine gear lube in my drives

 

[BRICH1260]

75-90w is what you want, synthetic without the limited slip additives. I`ve found that Volvo and Amsoil are acceptable. I personally use Amsoil, but primarily because the VP oil is hard to find locally.