Volvo DP Question

[Dave Patterson]

I recently bought a 28' steel hull work boat on Lake Superior. It has the 271 C engine. The upper gear box is a 1.61 290A but the lower gear is a DP-A as far as I can tell, based on the Volvo i.d. chart and the shape of the duoprop nose cone. This seems to be mismatched because the 290A specifies using engine oil and the DP-A specifies 90w gear lube. I drained the outdrive and it had gear lube in it. What would be correct refill lubricant. I forgot to mention that the boat was built in 1988 and the outdrive seems to be approx. the same vintage.

Thanks

 

[Don S]

Re: Volvo DP Question

It's been converted from a 1.61 single prop drive to a DP, use the GL-5 Synthetic gear lube, not engine oil for your now DP. PS: It should now be a 1.95 gear ratio. It changes in the lower, the uppers are all the same.
You will find OEM service manuals for your engine and drive up in the Adults Only sticky at the top of the forum.

 

[robjen1019]

Re: Volvo DP Question

Don, why do they use different fluids for the dp and sp. I know there are 2 props, but why not gl 5 in the sp.

 

[Don S]

Re: Volvo DP Question

Don, why do they use different fluids for the dp and sp

Because that is what Volvo recommends.

 

[zbnutcase]

Re: Volvo DP Question

And the DP works under heavier loads. 'nutcase

 

[Dave Patterson]

Re: Volvo DP Question

Don,
So the 1.61 290A i.d. plate on the upper gear case only refers to the ratio of the lower gear? Is there any marks on the replaced lower that would tell me if it's a 1.78, 1.95, or 2.30? Also, is the upper gear fully compatible with the DP lower?

Thanks again!

 

[Don S]

Re: Volvo DP Question

So the 1.61 290A i.d. plate on the upper gear case only refers to the ratio of the lower gear?

Yes

Is there any marks on the replaced lower that would tell me if it's a 1.78, 1.95, or 2.30?

Possibly, look on the propshaft bearing carrier under the anode.

Also, is the upper gear fully compatible with the DP lower?

Yes, the lower is also what determince the gear lube type, the upper doesn't care.

 

[Dave Patterson]

Re: Volvo DP Question

Don,
1.95:1 right where you said it would be. Thanks again.