So, driving around today i noticed a little bit of "extra" noise attributed to my truck.
At first i thought it was the tranny/clutch/throwout bearing.. But when i tested it in neutral and the various gears nothing changed.

Then, i opened up my rear window and the noise got ALOT louder...

So, its more like a howling/whistling sound coming from the rear end...
It only does it under load, not while coast.

What would make this noise from the rear end?

At higher speeds it sounds like a whistling and high pitched whine, while at 10-35 it makes my truck sound like a ferrari.. (The V12 kind, of course).

 

U-joints or R&P.

 

well i'll test the u-joints, i have a spare driveline so thats an easy fix if it is that.
i guess if it isnt, i'll be using one of my spare 4.10 3rds that i have conveniently laying out in my shop, lol.

it doesnt seem like u-joints because there is no vibration, but i've been wrong before.

 

haha, before I read the first post I said, taco-bell = noise from my rearend.
sounds like a pinion bearing. My fox's whines. My 85 4runner had a few years back had the exact same sound your describing, it lasted 50 miles and my entire rear end diff blew into many, many pieces.

 

well, i went out there and checked it out..
it appears as though my pinion flange has become VERY VERY loose.

should i tighten it and fill the rear diff up with oil? or should i swap the entire 3rd and play it safe?

 

swap the 3rd if you have other spares laying around..

it's probably already got BUKOO's of metal shavings in the rear end lol

so drain the fluid..flush the housing cuz of the metal shavings that are probably there..replace the 3rd and call it good lol

well, before you put the 3rd in, ya might have it checked out by a shop to make sure everything checks out good before you spend the time to put it in

 

I'll wait a few minutes while my rear driveline bolts soak in penetrating fluids.
might as well drain the fluid and check for shavings in the mean time.

 

You should be alright just retightening and restaking the nut.

If the noise persists, then I'd consider replacing the outer pinion bearing first or swapping the 3rd. Whichever seems easier to you.

I HIGHLY doubt that there's any significant damage to anything but a bearing or two(if that). That's my experience anyway, these are pretty stout diffs.

 

Hmmmm
I'm getting mixed responses here.

I pulled my spare 3rd anyways. The ring and pinion are in immaculate condition for it's age. Little bit gooey with old oil, but otherwise they're great.

Gahhh, too bad it's a 4.30 and i don't have a 4.30 front diff...
:/

UPDATE: Got driveline off of the diff side..
definitely need to tighten it, lol.

having troubles getting oil filler bolt to come out, its soaking in penetrating fluid.

 

Okay.
Uber Cool update.

So, imagine this terrible substance:
It's thick, brown, oily, smells like dirt, and it looks like sewage.
My rear axle is FILLED to the brim with it.

So.
Tightened the pinion flange..
Changed the diff fluid
Did not fix.

Looks like i'll be swapping in another 3rd member i have :/
do they make 4:30 front diffs?

 

Any ideas guys?

 

I don't know if there is a 4.30 but
you maybe able to locate that 4.30 front 3 rd member here if you going to be looking for one http://car-part.com/
I was able to find a 4.88 for my runner through this site for 250.00 which included shipping

 

My 4runner had the same problem, pulled it apart today, gear pattern is good, so I marked everything and pulled it apart, outer pinion bearing is toast, inner and carrier bearings are still good.

Basically all I needed to buy was the outer bearing($32) pinion seal ($15) and some gear oil, crush sleeve is still use able.

 

okay, well, i'll probably end up pulling the 3rd tomorrow and dropping in the 4.30 temporarily and let a pro deal with my diff lol.

 

An early automatic truck/4Runner might have 4.30s. This is before the 31" tire option IIRC.

 

the 3rd is from a 79'.
it's considered a "4.37"

how hard is the 3rd member swap?
just gotta pull the axles and the diff comes out, right?
cuz i might just do that tomorrow

 

yep....that is how you do it!...heavy sucker they are, make sure you seal it up good don't want it to leak

 

Reusing a crush sleeve or using one period on a truck that you wheel is a poor choice. Use a solid pinion spacer on a truck that goes off pavement and sees any abuse. A buddy of mine learned this the hard way last weekend. His crush sleeve crushed, ruined his gears and "inscribed" his carrier for him.

http://forum.ih8mud.com/79-95-toyota...ml#post5213613

 

well...
hmmm...
i'm gonna go jack up the rear end and see if i cant replicate the noise..
hopefully it's in the diff...

 

UPDATE: It's in the diff.
It clanks, rattles, clunks, etc.
I'm pretty certain its the pinion bearing because i can see it jiggle a bit, even with the pinion flange tightened.