changing diff oil, can someone please help me out

[blueb8llz]

i have never seen the inside of a diff besides the pictures on the instruction manuel. for the last hour or so, ive been just reading up on diffs etc etc...
so i want to change my diff oil in both the front and back on my emaxx 3905
i hear i want heavier in the front. i dont do any racing at all, just bashing. im thinking 100k in the front and 75k in the back. what do you guys suggest?
but my main concern is this, where do i put the diff oil? i have no idea or clue. i hear people pack the cup with lube. i cant find where people put the new oil. all i can find is, im suppose to clean with denat. alcohol...but is that for the regreasing and lubing...im sooo confused with all this. can someone please shed some 411

http://www.youtube.com/watch?v=Y4LF4r6xvdU

[blueb8llz]

so since im not regreasing i can just pour out all the diff oil and just replace new oil?
sounds like i just pour in the new oil in the diff housing..

Originally Posted by blueb8llz

so since im not regreasing i can just pour out all the diff oil and just replace new oil?
sounds like i just pour in the new oil in the diff housing..

That is what i do and i grease the external gears.

[blueb8llz]

whats the external gears? someone told me that the oil wont just pour out, its waaaay thicker than honey. and that i would need to take out all the parts, is this true? i believe my stock is using 30k

you should use a seal (blue pad in the video), and the oil will stay in the cup. grease the outside diff gear, and the pinion gear that goes through the diff case.

and 100k/75k seems like alot to me.. idk. I'd think 50/30 would be a better choice, even for bashing..

[blueb8llz]

but why do i want to use the blue pad when im trying to take out the old oil.
reason why i chose 100/75k was that when i accelerate, my truck pulls to one side, and i thought that heavy diff oil would solve my issue...am i correct about this, or is my problem caused by something else?

[bdebde]

heavy oil will likely make it worse (pulling to one side). Check all of your suspension as well first.

[blueb8llz]

make it worse? greaaat. now im really confused. ive checked my suspension..i think.
what do i need to look for? theres not much to check since i dont use any spacers. all bottom and top shock caps are still on. no bent shafts. no leaking oil..anything else to look for?

[Arct1k]

have you checked you bearings?

[blueb8llz]

i have actually. the bearings to my front right wheel was bad. i replaced that and it made the steering slop dissapear. so i thought that was the problem, took it outside for a run...still same thing but im sure it helped.