let me start off with a disclaimer....i know there is no way to predict this, but for conversations sake...

how much time do you think is left on the rear end of my 3.4, it has a rhythmic grinding sound that increases/decreases in sound and frequency with speed, and it just the other day started howling/whining above 50mph. its just a standard open diff and it has 240,000 on it

I have already got some prices and for a full rebuild the shop i go to quoted $1200-1400 for a full rebuild, a few hundred less if all the gears are good and they just have to replace the seals and bearings, and $300 to swap in a new rear.

 

On its last Peg leg. For what it is worth, forget the rebuild. Buy a complete rear from a salvage yard, it will be cheaper.

 

Sounds like a wheel bearing is going. With that many miles, it would not surprise me. Check the fluid and see what it's condition is while you're at it. You can also jack the rear up and spin the tires and see if you can narrow down where the sound is coming from. No sense in replacing the whole rear if it's just a wheel bearing.

 

agreed it would be way cheaper, i looked it up at the local pick and pull and its like $150 for a rear for mine, but i dont know how much i like the gamble. its something i'll be thinking over whilest i wait for the rear thats in there now to die.

 

last time i changed the fluid ~20,000 ago it seemed normal, with very little metal on the magnet, oh and it has been making that grinding sound for YEARS.

while im remembering things i do remember when i was changing the gear oil, when i spun the tire to inspect the gears it would get to a point where it would stick pretty good and take me grabbing the wheel and turning it instead of a finger or two to spin it

 

That grab could be the brakes, or could be a bearing hanging up. If you can find a complete rear unit for $150 that has decent miles, that would be the way to go.

 

the big thing that will make up my mind is, do i want to spend 1400 bucks on something i dont plan on keeping on the car?

 

I think you know the logical answer to that one.

 

have you checked the carrier bearing?

 

yes yes i think i do....so with that in mind what models had at least a 3.23 rear end on them or higher, i dont want to get too high though i do enjoy the good gas mileage? i believe that is what is on mine since it has that oh so rare third pedal cluttering things up down by my feet