Rebuilding Rear diff.. Howling and leaking front seal..

[everpresentnoob]

So I just got a 300Zx for a decent price, 100 bucks... for that price I couldnt say no. Dudes dad wanted it gone and jokingly asked for a hundred. I jumped on it...

Anyway, the rear diff is making a speed dependant howl. it starts about 15 miles an hour and as speed increases the howl gets higher until it kinda fades into the background at highway speeds.

And now tonight when I got home from work (80 mile drive) I smelled gear oil. stuck my head under the cars back and found the diff and brace under the front if it are covered in oil. So its parked for now until I can sort this out.

I have been looking for a walk through on rebuilding it, but havent really found much yet. the few I have found are not complete, or at least not complete enough for a guy that has never pulled the carrier ot of the housing. I have no clue about the shimming and I dont have a dial indicator to check lash and what not. not that I even really know what that is.

Can any one help?

[nissanfreak12]

Rebuilding a rear diff is very difficult if you don't know what you are doing, and can be catastrophic is done incorrectly. Howling is a sign there is either a really bad bearing or the lash is way out of spec.

My advice, the rear ends are all over the place and relatively cheap compared to having someone rebuild your rear end. Find someone selling one, the whole thing, not just the internals, much easier that way.. J30 has them and 300zx NA, Q45 has the same rear as you but will have different gearing 3.69 vs 4.09(slower take off with a higher top speed). TT's are different due to axle shafts and yoke. I also think 240sx rears will work but no LSD unless you get a newer s14.