1987 4runner. 5 speed, 22RE. Originally ADD, covert to manual(if it matters...)
I'm looking for some help and advice. Friday night I got towed home. I was hearing a screaming wining noise coming from either trans, t case or rear diff. I really couldn't tell. The noise got real bad friday night and then the whole truck started shaking. After some advice here a couple days ago, i took off my rear driveshaft. The U joints were fine, I locked the hubs, put it in 4wd and drove around a bit. In low gear, it shifts fine(as good as a 240,000 mile trans does). There is still a really bad thumping noise, but it seems be coming from the rear end. In 4low in 1st gear, I got out and walked along side the vehicle. Im 75% sure its the rear diff, just hard to tell trying to run/ walk half bent over along a moving vehicle.lol

So now my 1st question is with the vehicle being stationary, how can I tell it is the rear diff? How should the wheels act with the back end jacked up? There seemed to be a 1/4 to 1/2 inch of play on the driveshaft when it was on. Eventually I am going to pop out the axles and take out the third member, would that be the easiest to tell? See if there are chipped teeth and what not?

2nd main question is if I find a 4:11 third member at a junk yard or craigslist, what should I look for to make sure that one is not bad? Pretty much if the donor vehicle is a 4cyl, 5spd, non turbo, non auto they will be the same ratio right? I see know need to get a new 3rd member from the vendors here when I'm on 30'' tires, but plan on being on 33's this year. Then I will spend the big bucks to get the whole assembly already set up, with lockers

Thanks guys, I'm just in a bind. I have to commute 60 miles to work every day, and basically this truck is my life line

 

Drain the oil and look for excessive metal shavings.

No, you'll need to confirm the gear ratio.

 

If it helps, check out my DIY in my sig for replacing the gasket back there.

Good luck!