I'm going to be changing some fluid here in the next week or so. Just had a Shep rebuild done and I want to change the fluid after 500 miles. It has fresh Amsoil in the t-case. I generally used Diaqueen before, but I suppose the Amsoil is ok. I haven't done the rear diff fluid in 15k miles or so and it's due. Figured I'd flush the brakes and change the engine oil while I'm at it too.

Anyway, I still have Diaqueen from the last time I changed it, maybe 2 years ago.... It's in the tin can it came in. I've had the cap on it, but it's been unsealed for that long. Should this be an issue? Since the t-case has fresh Amsoil in it, I should still have enough left over from 2 years ago of the Diaqueen for the rear diff. It beats ordering a $60 Gallon of Diaqueen.

Is it being unsealed for that long a problem? I'd think not.

 

Use it. The stuff is made to survive in a hot gear box run hour after hour down the interstate and not oxidize.

 

Gear oil does not have a shelf life (but it doesn't last forever..) , contrary to brake fluid (which does have a shelf life). You'll be fine, as long as it not contaminated.

 

I thought so. I have some Motol dot 4 brake fluid sitting in my garage for 2 years I defiantly know I shouldn't use. Gotta buy more of that.

 

You'll be fine using the Diaqueen. I have been doing the same for years. Oil stays fine.