Thinking about changing the fluid in my dana 30 and 8.25. Im just looking at it as its probably never been changed before and im going to have time this weekend. I have looked around a little bit but wondering if you guys know of a thread or just a link to the main steps and helpful tips to doing this. Thanks everyone, Taylor

 

its simple remove cover drain gear oil replace cover using permatex blue for the covers remove plug fill to plug hole your done

 

unbolt the cover, pry cover off, let drain and clean out, run a silicone bead around the cover, install cover, remove fill plug, fill to the bottom of the fill hole.

 

what he said

 

thats what i thought but i was thinking surely theres more to it. but thanks

 

Nope, thats it.

 

what weight gear oil is best to use? and any brands better then others?

 

I use 75w90.

 

If your 8.25 is an LSD don't forget to use some LSD additive along with the oil.

 

I am getting ready to change my diff oil soon too. When taking off the diff covers, leave the top bolt partially screwed on until after you break the old gasket seal and the oil drains out. Otherwise, your diff cover could fall into the oil catch pan as you break the seal, creating a splash and embarassing mess of oil! (not actual personal experience, but read this somewhere). Good luck!

 

If you wheel often you can do what i do. Walmart carrys 80w90 oil in 20L for 39.99 I run that and change it several times a year depending on the frequency I wheel.

No matter how good the oil is, it'll still get dirty being wheeled so I never bothered with really good oils. I just change it often. I don't think I've ever gone more than 4-5 000km without changing the diff fluid.

 

will 75/90 or 80/90 still be good to use when the temps in the winter drop down into the negative numbers?

so far just this winter its got down to -13, but last year it got down to -26.

 

Either is fine, gear oil isnt like motor oil.

 

Also remember to get the remains of the old silicone seal off of the cap and the housing. I use a Spackle knife sharpened with a grinder, works every time

 

I wouldn't use 80/90, pretty sure you are supposed to use synthetic (75/90)
Also +1 on the LSD, if you forget the friction modifier your diff will make all kinds of weird noises and wear out the clutches about twice as fast.