Merc high performance gear lube ok for volvo dp outdrive?

[hawkeye9802]

Hi and thanks in advance for any input. I have always run mercury outdrives and am changing outdrive fluid on my first volvo, a 1994 dp-d1. problem is the local marina mostly services merc and only has quicksilver high performance gear lube which the mechanic - who i have had good service from for years - says he puts in all of the volvos he services without any trouble. He is a mercury guy though. I did buy three quarts of it but am having a few reservations about not using the volvo duraplus 75w90 synthetic. I need to get the boat in storage before space fills up and it would take me 10-14 days to have the volvo fluid shipped. Am I being anal retentive or is the mercury fluid fine to use for one season and then switch to the volvo fluid next fall?

 

[dypcdiver]

If it complies to "GL5" then no problem.

 

[Scott Danforth]

the volvo DP's require a synthetic GL5

I have had problems with the Mercury lube, and have long since gone with Amsoil

 

[jerryjerry05]

IF???? there is no water in the drive??
Then just pull the drive and check the u-joints.
WD the heck out of it and put it back together till spring.

 

[scutty]

(The server threw an error on me so I apologize if this gets garbled or is repeated)
I'm very interested in this thread. I hate paying $15-17 per quart, paying for shipping, waiting... The shop manual calls out a Mobilub SHC as an alternative but that is no longer available at least in the north east. They've put "LS" Limited Slip additives in everything. The VP drives have a cone clutch in them so anything with LS additives would be bad. I think this why so many folks have had mixed reviews of the Merc oils. (just a theory) I also like the Amsoil product that is GL5 and has the water absorbing / displacement additives you want in a lower unit. And it's readily available. IMHO the two best choices are oem VP lube or the Amsoil. Looking forward to reading other opinions & advice.

 

[dypcdiver]

Interesting question scutty, I too have been thinking and asking about just that, LS as opposed to SHC.
Mobil will tell you that LS is perfectly suitable for gear and transfer boxes, not just LSD axles. The LS just means that it includes a "friction modifier" that allows the clutch plates in LSD's to work correctly.
Now if LS is fine (according to Mobil) for gear boxes with their brass (yellow metal) synchromesh rings which work in exactly the same way as the cone clutches of the Volvo Penta outdrives, then I suggest as the SHC is only still available in Europe for heavy duty industrial applications that Mobil 1 LS should be OK for outdrives. Your choice.

 

[doyall]

... The LS just means that it includes a "friction modifier" that allows the clutch plates in LSD's to work correctly. ...

The "work correctly" part is the key. "Work correctly" is to allow some slippage so that LSD axles do not chatter in sharp turns. I do not want the cone clutch in my VP outdrive to slip any. I experienced that phenomenon when I used M1 LS gear lube.

ExxonMobil informed me via email that their Mobil Delvac Synthetic Gear Oil 75w-90 is a direct replacement for the Mobilube SHC Full Synthetic 75W-90. I have used the Delvac problem-free for two seasons and about to put it in again. If you shop around you can find it for less than $10/qt. shipped when bought in multi-gallon quantities
.

 

[scutty]

Great lead on the Delvac. As far as I can tell none of these Mobil options are designed for marine use. i.e. Any water that infiltrates will separate out where as marine oils will keep water in suspension. I searched more on this topic and found some comments from the venerable Don S that this is the big difference in available gear oils. Since it is changed every season maybe it doesn't matter much? Any thought about these water absorption / dispersion additives in the marine oils?

 

[dypcdiver]

My outdrive has been fed on Mobil 1 75w-90 SHC for the last 10 years. Strangely just today I have ordered a 20 Ltr drum from France as I use it in my Toyota Land Cruiser too. Although I have to feed the rear axle with Castrol LSD Syntrax as here in Europe Mobil 1 LS is not available, Weird.

 

[billbayliner]

Not to jump off of subject but the DP-D1 drive was not available in 1994. 1994's drive was the DP-C and at the end of the year a few DP-C1 went out. I only mention this so, if the need arises, you do indeed order the proper parts.

 

[Walt T]

Marine oils will help keep your drive alive if water seeps in, but you must find the source of the water and fix it. Using marine oil is not a fix.