I put 4.88s in my T last year and i just got around to changing the gear oil today, the oil came out like a sparkly silver grayish color, a little gritty, should i be worried or can i just pass it off as the glaze and junk on the fresh gears i put in??? <img src="/forums/images/graemlins/barf.gif" alt="" />

when you installed the 4.88's, did you immediately change the diff oil after a couple of hundred miles?

nope, didnt know i needed to at that time, probably should have researched it a little, i had the work done at the dealer, they didnt say nothin' bud im sure they would be glad to have me back in after a gear failure or two...im not really worried about it right now anyway, havent received any answers yet on if i should be.

I changed the front a little later today, the oil looked alot better in the front, since it gets used so rarely...

There were no chuncks of metal or anything, there was one small piece of filing on the drain plug magnet, otherwise it all looked like a little metal glaze.

always change the diff fluid after a few hundred miles after installign new gears. they told you nothing about breakingin gears. drive 10 miles (easily), and then let it cool. then drive it. hopefully you will be okay, but what you did is not the way to break in new gears.

Yup they just gave the truck back to me and said that'll be $1100, and then i was off and going. I wasnt hard on the diff when i first got it setup. Im just worried that the fluid not being changed for the last 12k miles might have hurt it,

I read somewhere it was probably gray because water got in there, ive never crossed any streams or anythings, but ive been in some deep water holes, i guess it got contaminated, im sure itll be alright though, diffs are pretty tough, i guess what happened wasnt exactly ideal.

the color is that phosphor coating or whatever it is on new gears.

OK, I'm in the same boat. I had an LSD installed about 8k ago. No mention of getting the gear oil changed. I haven't noticed any problems, thank goodness but I should be getting that rear diff gear oil changed ASAP shouldn't I? Any recommendations on a good synthetic?

gear break-in is important for new gears. personally, i would chnage things pretty quickly after a LSD or locker install just since everything got adjusted. with just an LSD, you are probably better off than someone who got new gears.

I put some Mobil 1 full synthetic in mine, got it for about $7.99/qt. you'll need 3.1 qts for the rear diff, and 1.8 qts for the front, 1.1 for the transfer case, that is if you feel like going nuts on all the diffs and T-case.

Spoke to the Toyota Stealership today, they said there "isnt a gear break-in period", kind of strange they wouldnt know anything about that. <img src="/forums/images/graemlins/rolleyes.gif" alt="" />