Frothy Gear Oil - M813

[Wreckclues]

While draining my Spicer 5 Speed the oil came out frothy. Is this normal?
I had just done a short run, ran through the gears with the transfer case in neutral then drained the oil preparatory to a diesel flush. The oil also started draining from the filler port first. I checked for water with Gasoila which was negative.

Backstory, 8 months ago I mixed an 80/90 GL4 with what I assumed was the original 80/90 GL1 and the transmission did not like it. Ran through the gears fine for the first half mile then lost all power in all but first and barely creeped home. After a fruitless search for an 80/90 GL1, I settled for a 90W GL1 to refill after draining. After this everything seemed to be fine, but just to be sure I wanted to do a diesel flush.

 

[Mullaney]

View attachment 926469View attachment 926470

While draining my Spicer 5 Speed the oil came out frothy. Is this normal?
I had just done a short run, ran through the gears with the transfer case in neutral then drained the oil preparatory to a diesel flush. The oil also started draining from the filler port first. I checked for water with Gasoila which was negative.

Backstory, 8 months ago I mixed an 80/90 GL4 with what I assumed was the original 80/90 GL1 and the transmission did not like it. Ran through the gears fine for the first half mile then lost all power in all but first and barely creeped home. After a fruitless search for an 80/90 GL1, I settled for a 90W GL1 to refill after draining. After this everything seemed to be fine, but just to be sure I wanted to do a diesel flush.

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So, I am just fishin here but you shouldn't have gear oil flowing out of the filler port. I mean oil will swell a little when it gets warm - but not like the stream you have pouring out of the filler port. I am also a little concerned that your "Oil after 8 Months" looks so black. Maybe if you get a similar cup like your "New Oil" it will look similar? Looking at the oil coming out of the drain - it looks milky (maybe frothy?)

An overfilled transmission will "froth" up the oil. You should fill it to "about a knuckle" below the fill port.

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[Wreckclues]

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So, I am just fishin here but you shouldn't have gear oil flowing out of the filler port. I mean oil will swell a little when it gets warm - but not like the stream you have pouring out of the filler port. I am also a little concerned that your "Oil after 8 Months" looks so black. Maybe if you get a similar cup like your "New Oil" it will look similar? Looking at the oil coming out of the drain - it looks milky (maybe frothy?)

An overfilled transmission will "froth" up the oil. You should fill it to "about a knuckle" below the fill port.

I may have overfilled the transmission last time. My driveway is on a slight grade. The truck was pointing up hill when I filled it last. I'm pointing downhill now so if I fill it level with the port, that should be about a half knuckle when level?

The diesel flush was pretty dark too. I've read that synthetic oils are designed for transmissions with filters as the oil entrains the sediments. I figured the sediments in my Spicer were initially entrained when I mixed the synthetic with the mineral and gummed up the transmission.

 

[Mullaney]

I may have overfilled the transmission last time. My driveway is on a slight grade. The truck was pointing up hill when I filled it last. I'm pointing downhill now so if I fill it level with the port, that should be about a half knuckle when level?

The diesel flush was pretty dark too. I've read that synthetic oils are designed for transmissions with filters as the oil entrains the sediments. I figured the sediments in my Spicer were initially entrained when I mixed the synthetic with the mineral and gummed up the transmission.


View attachment 926473

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I would guess maybe? On filling the transmission. Might even be worth getting it onto flat ground later and pull the filler plug and check it. Low is better than too high (fill level).

I hate to say I don't really know about synthetic oils. What you said makes sense though. I do know that "bright metals" need the right oil in the transmission...

The clean up with the diesel flush should make you golden.

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