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VP-270 with 90 wt?

T

Texascrew

New member
Hi, I have a VP-270 SN 27107282 and just drained it......and it has 90 wt in it! I am sure that many of you know the proper wt of oil is 10-30 or 10-40. I recall one person saying that not ALL vp-270 s used 30/40 wt oil. It does not shock me that the local boat dealer serviced this wrong. I just want to see if anyone knows for sure it does not require 90 wt/ Thanks for any help and advice.
I just replaced the bushing for the cooling neck and was putting it back together and wonder if i should put 90 wt in it.
Rick
 
There's no reason to put gear oil in it but it's a really good idea to do the pressure test before you fill it back up with motor oil.
 
Yes, I'd do a pressure/vacuum test prior to adding the oil.
The reason for doing this prior, is that the pressure test will not be accurate if oil is present against the seal lips. The oil actually aids in the lip providing the seal, giving us a false/positive.
The vacuum test doesn't care if oil is present.
These are both Leak-Down tests that involves a time element.
Turn the prop shaft and the eccentric piston while under pressure and vacuum.
The eccentric piston seals are generally the culprit for a breach.

Here's the deal on the AQ series drives regarding GL-4 or GL-5 gear oil -vs- regular 30W engine oil.

The AQ series transmission is cooled via the "cooler" lower unit oil that is pumped up to the transmission.
The oil then gravity feeds back down to the lower unit.
The s/p drive lower unit incorporates a "slinger" pump that is driven from the lower unit "driven" gear.
This slinger pump is a die-cast aluminum impeller pump.

The impeller is keyed to the driven gear via one or two small spring or roll pins.
If heavy gear oil is used, there's a chance that these drive pins will become sheared off from the excessive force against the impeller.
No drive pins, and no slinger pump action, nor any cool oil being pumped up to the transmission.
The transmission will then over-heat on us. :mad:

You may want to pull the prop shaft bearing carrier, and take a look at your slinger pump. See if it is stationary with the driven gear.
If not..... you'll need to pull this apart, and repair the drive pins.
See post #9 in this thread.... it will show the impeller location, and also an image of a puller tool used to remove the carrier.

It's farily easy to do, and while in there, you can replace the two prop shaft seals.
No change to any shim values occurs if you keep the shims as they were....... so no need to worry about that.
Two new seals, two new carrier O-rings, two new O-rings from the dip stick and drain plug are all that's required.
(no fill plug nor fill plug gasket on the 270)


Now, the Duo Prop drive does NOT use the slinger pump. It uses one of the two driven gears for oil pumping.
This drive will require the GL-5 gear oil.
This may be where the shop is mistaken, and where the GL5 is thought to be correct for the s/p drives.
You may want to explain this to the shop that you are discussing this with.
They need to know this so that they don't cause any damage in the future.


BTW, I've repaired these slinger pump drive pins several times over the years.
This is not all that uncommon to see that some knucklehead has not read the OEM manual, and ends up using the wrong gear oil viscosity.

.
 
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Joe, that is a good read for the OP here.

It suggests using the drain port for the test instrument. I'll suggest that either works just as well, and the dip stick port is actually easier to use.
Install a new O-ring on the drain plug prior to the testing.


It suggests turning the prop shaft and the universal shaft....., but makes no mention of rotating the eccentric piston. I always rotate the piston as well.


Side note: We can expect the drive to hold under pressure if all seals are OK.
However, the main drive gear seal is a single lip seal, that faces in a manor that seals well against pressure, but may not hold substantial vacuum.

images


Since this seal resides within environment of the drive shaft bellows, it's not a deal breaker if the vacuum reading is on the low side, IMO.



The eccentric piston seal............
images


and the combined back-to-back prop shaft seals.............
images


are double lip, so holding vacuum is generally not an issue here.


.
 
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