Walter RV 40 V drive fluid change

[ron54]

New to me 1985 3697 Mariner with Crusader 454 ch350, Velvet Drive 1:1 to RV 40s.

Have the Velvet drive trannies done, now to the V drives which are independently mounted and easily accessible through hatches in the salon. Have found several manuals for procedure, only real question is fluid type. I have read 30 weight HD motor oil which I can only find in detergent type. Others say non detergent 30w which is available at Wally World and part stores. I called Walter and they said 30w motor oil, either detergent or non is fine. Another manual states to add 2 oz. Molybdenum disulfide (molykote) for break in, not needed after that but good to add. To confuse things further my original Crusader manual lists EP68 or APG-80 gear lube, both difficult to find.

Probably overthinking this, will go with what Walter company said, but any thoughts welcome. Also thoughts on the Molykote.

[bud37]

Out of curiosity, what is in them now......what general color is it and does it look clean in there. FWIW old gear oils generally have a distinctive odor.

Yup do what Walter says.

Sometimes you can find gear oils like that at tractor supply places in bulk, equipment dealers etc.

[ron54]

Not sure what is in there, looks pretty clean seems to be motor oil.

[ron54]

Attached is the portion from the manual. Sent Walter an email to clarify about the Molykote and oil.

Here is response

“ No need for molykote, it can hurt more than help.

You can use SAE 30 heavy duty motor oil, either detergent or non detergent.”

Interesting that they longer recommend molykote.

[km1125]

I think more interesting is the comment "it can hurt more than help". Wonder why they say that?

I could see them not recommending it, as it could be "overkill" and unnecessary with the increased shear strength on modern heavy-duty oils.

[bud37]

Ron , can I suggest, my advice would be and this is how I would handle it .....with whatever fluid you choose to use.....flush the case with it.

By this, I mean drain and fill, run, then drain again and fill again a few times.......that way you will be sure of what you have in there. This only applies if you have no idea what is in there now and will ensure consistency.

[ron54]

Yes I suppose the moly must not be needed anymore. Also I think the flush is a great idea, I will get some sae 30 HD at Wally World for the flush then some better quality. Did some research and the Valvoline VR1 straight sae 30 supposedly has a lower detergent content but higher zinc and phosphate (zddp) like the oils did back when this drive was made. May go with that.

That begs a question about engine and genset oil, I probably should post a new thread for future reference.