What color and thickness should the gear oil have been?

[Zack1978]

Hey everyone,
I decided to change the front and rear diff oil in my 1979 Toyota 4x4 short bed truck. The truck only has 37,000 miles on it, however I don't think that the diff oil's were ever changed since they were put in at the factory. Well when I did the front, the oil was almost a gray like color, it smelled horrible and it was on the thick side ( the truck was warmed up for a few miles in 4wd drive). Is that normal? The rear was also kind of gray and thick. On both the front and rear there was some metal shavings stuck to the drain plug, is that normal? I put in fresh Amsoil gear oil, but I think I might change it in a few months to see if the Amsoil cleaned things up in there. The truck was only ever used as a plow truck, so that is why the miles are low.

Thanks,
Zack

 

[2ndGenToyotaFan]

I dont' have a lot of experiance with 27 year old gear oil, but gray seems a little wierd..... I'd change it again soon just to flush it out good, like you said.

 

[Cube Dweller]

Zack,

I would buy cheap gear oil for a while and change it frequently to flush out whatever crap is in there. Yes, some fine metal particles are normal, that's why there is a magnet in the drain plug- to collect them. Gray isn't great but chunky white would be much worse (water contamination).

 

[4in100]

Gear oil should be think and stinky. Otherwise you wouldn't know it's gear oil. It helps distinguish from engine oil. It should also be in the 90w range so it's much thicker.

 

[bigbrowndog]

should be light brown, Castrol Hypoid c80w/90 or similar .
trans 4 speed 3.1liters
5 speed 4.4liters
transfer early 1.7L
late 2.5 L
The grey color could it have been from a molybdum disulphide addative or P.T.F.E.
treatment to help the gears to shift easier? I would just refill with 80/90 hypoid, perhaps just 70/80 or 80 in winter there.cheers


What color and thickness should the gear oil have been
Thought from avitar you were talking about a 60 series, actually thought I was in 60 sect, not new posts,, bedtime 1.50am.
Anyway hypoid oil stinks..and does not wash out the clothes. cheers.

 

[Jonathan_Ferguson]

Gear oil should be think and stinky. Otherwise you wouldn't know it's gear oil. It helps distinguish from engine oil. It should also be in the 90w range so it's much thicker.

Gear Oil doesn't always have a smell, I don't recall the Gear Oil I've bought ever having a smell.

Differential Gear Oil doesn't necessarily have to be thick. I use Valvoline Semi Synthetic GL-5 SAE 75W/90 and I've got Lock Rights.

 

[Jukelemon]

It was "grey", or what I would call white, due to water/water vapor in the diff. It is trash and probably has been for a while. I would follow the above mentioned advice and buy some gear oil, not synthetic, run it in your diffs for 200 miles and then change it. Do this two times or three and then get some high quality oil and fill it up. Check the breathers to see if they actually work. Understand that you need lock your front hubs during this NOT put it in 4 wheel drive.

 

[IDave]

Some of the Lucusoil type additives have given mine a white discoloration.

 

[bigbrowndog]

Nulon G70 manual gearbox and diff treatment will also make it go a milkish white similar to water.Thats also a P.T.F.E."polytetrafluroethylene". The nulon XL90 similar for extreme pressure is great to use in assembly,same color.