Need Advice, Water in The Transmission (NV4500) (1 Viewer)

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Need expert advice since I am trying to save $100 on the NV4500 oil if possible. Tranny was completely rebuilt after running it with no oil. I filled it up with 5 quarts of redline mt85. Ran out of time to begin the install so I left it next to the truck, some heavy rains/wind came down overnight and most of Wednesday. I had put a nitrile glove over the top shifter hole, then a trash bag with a jackstand on top (for weight). well, the next day trash bag/jack stand were gone and the glove had a couple of slits so I have to assume that water went in. would you drain and buy new oil? or drain and try to separate water from oil and reuse/refill? or, (I understand that with water/oil mixture. the oil will float to the top) should I just try to drain some of the water out?

I would hate to ruin or shorten the life of the tranny (and blow another $1300) by not doing the right thing.

TIA
 

rhah

Admit it, your cruisers jealous
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Gear oil is cheap, even if it’s synthetic

FDE9C4BE-C3BE-4D4C-90E4-5077F9DFE445.jpeg
 

OSS

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If there's any water now in the transmission, it's pooled into a tiny puddle at the bottom of the case — maybe at the drain plug.
Manual transmissions don't have oil pumps or sumps so the oil lubricates everything by getting splashed around by the spinning gears. There's probably an inch or more of clearance between the largest gear in the case and the bottom of the case.
It's hard to imagine the oil getting whipped up enough that the biggest gear could fling that little bit of water up into to gears.
If the truck was tilted back so that the drain plug was the lowest spot in the transmission and the drain plug opened a tad - any water would likely come out first.
<just guessing on this>
 

OSS

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Just for reference: Toyota calls out SAE 90 weight GL4 gear oil for the original transmission--- and that exact oil has never been available in the USA
 

GLTHFJ60

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Definitely change the oil.

The nv4500 does take unicorn blood for fluid. Sucks, but I'd definitely drain and replace. Any water in the case will circulate and cause damage.

There's no drain plug which sucks. If there was, I'd say drain till you see oil, then top up.
 
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I’d drain it and fill it with the cheapest spec’d oil. Rock it around a bit and drain it again. Inspect for water and repeat until it comes out clean then put the good stuff in once you know it’s free of water.
 
Joined
Aug 24, 2005
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Need expert advice since I am trying to save $100 on the NV4500 oil if possible. Tranny was completely rebuilt after running it with no oil. I filled it up with 5 quarts of redline mt85. Ran out of time to begin the install so I left it next to the truck, some heavy rains/wind came down overnight and most of Wednesday. I had put a nitrile glove over the top shifter hole, then a trash bag with a jackstand on top (for weight). well, the next day trash bag/jack stand were gone and the glove had a couple of slits so I have to assume that water went in. would you drain and buy new oil? or drain and try to separate water from oil and reuse/refill? or, (I understand that with water/oil mixture. the oil will float to the top) should I just try to drain some of the water out?

I would hate to ruin or shorten the life of the tranny (and blow another $1300) by not doing the right thing.

TIA
I think I would suck it up and pop for new oil. But if you are set on reusing, drain the oil into a milk jug, let the oil settle and place the jug into a freezer overnight. Pour out until you get to the ice. Or you could try heating the oil on a hot plate and boil off the H2O. I think 250 degrees should do it. Either way would be a cool science project.
SimS
 

GLTHFJ60

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I’d drain it and fill it with the cheapest spec’d oil. Rock it around a bit and drain it again. Inspect for water and repeat until it comes out clean then put the good stuff in once you know it’s free of water.
You really can't do that with nv4500s. Nv4500s use carbon fiber lined synchros which burn up real quick if you use the wrong fluid. Gotta use something spec'd specifically for nv4500s, and it's always expensive, like $20+ per quart. Nothing cheaper exists within spec.
 
Joined
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You really can't do that with nv4500s. Nv4500s use carbon fiber lined synchros which burn up real quick if you use the wrong fluid. Gotta use something spec'd specifically for nv4500s, and it's always expensive, like $20+ per quart. Nothing cheaper exists within spec.

I will add that to my GTK file for future reference.
 

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