Rspct2All

Hello everyone,

Issue:
My 3rd Gen 4Runner SR5 2WD AT V6 has been having this hum noise when I accelerate from 40MPH - 65MPH it's very noticeable (most noticeable at 60MPH), or when I let go of the gas peddle on a 25MPH residential street, I can hear some gear-like noise as the car rolls. When I put the car into Neutral on the FWY at the loudest point, 60MPH, the sound gradually goes away; and same goes on the 25MPH streets.

Solution from mechanic:
Replace the entire Rear Axle with a USED Rear Axle = ~$980
New will cost a lot more, according to the mechanic.

Question:
Should I stay away from a USED rear axle?
I like quality parts to be put on my baby.
How much is a new rear axle?

OR... could it be something else?

I'm torn between ujoints, pinion bearings, wheel bearings...

As I've read through here for 3 years now, some folks suggest other mechanics for other suggestions and opinions.

Please give your input, anything would help, thanks!!!

J2F42C

When is the last time you have greased your joints? If it has been some time, get under there and grease them with the two types of grease. There are a couple of good articles for such so use the Search Engine.

If you are hearing the noise as you describe, it may be the bearings. Had any rear axle seal trouble lately?

Get a second opinion.....

BigBallsMcFalls

is it a rumble ? most likely it is the rear axle bearings. those are the first
thing to go and most likely suspect. they only go bad when the vehicle has
been mudding or axle under water a few times and not serviced. the bearings
will crumble, make a rumble, and just need to be replaced along with the
antilock brake timing cog.

700 bucks for a shop to do it.

brian2sun

A mechanic that tells you to replace the entire rear axle also needs to tell you what's wrong with that axle to warrant replacement. Otherwise, it sounds like he just doesn't want to diagnose it. IMO, that's like saying the engine sounds funny, just replace it.

914runner

It is most likely either the pinion bearings or carrier bearings are too worn out and have developed slop. Just replace the third member with a used one or have yours rebuilt with all new bearings, new R&P, and a SOLID spacer instead of the crush sleeve.

Most likely the crush sleeve is what caused all of this. They can over time get crushed more than they were when installed and torqued. This allows slop in the pinion bearings which ruins them and your R&P. It has happened to me twice, the first time I blew three teeth off the ring gear.

The axle shafts and wheel bearings should be fine. The wheel bearings rarely wear out in these rigs. My '91 4Runner has the original wheel bearings with 335K on them and I'm just now replacing them.

crolison

sounds like your diff is messed up.

just get a used one (50-150 bucks) and throw it in your rear, now is the perfect time to upgrade to 4.10's.

Also any 8" toy third will go into your housing. I'd look for a v6 8" third that someone is selling cheap.

Ironmike4x4

Have they torn it down? I had one a few days ago on a Ford Ranger where the bearings had too much play in it and worn down the inner axle tube itself. We replaced it with a junkyard one. I would ask to look at it and see instead of a tech that wants to just replace it instead of diagnose/fix the concern.

hross14

OR go to one of our sponsors Toyota Sponsers here on the board and he will sell you a brand new E-locker for $1000--little grinding--little welding--little wiring and BOOM you fargin locked

DailyDrive

Replacing rear end? Axels? Gears? Bearings? Why is this a guessing game? What happened to good 'ol troubleshooting?

Put it on jack stands and simulate driving 60mph. Then listen. Get a mechanic's stethoscope for $10 if necessary.

MaK92-4RnR

I vote differential. my dad's mustang had the same issue, and eventually his gears went out.

hross14

it is pretty common on the 8" that once that rear starts howling (this is not a prison joke) that little ol pinion bearing is usually the reason.

But this is what i would do--either get your rear rebuilt (circa $800-1000 bones) (ZUK does a great job) or get one from champion toyota (sponsor) e-locker or not and rebuild the whole rear end while you have it out--bearings, seals, brakes, the whole sha-bang. I especially say bearings because if they fail your axle and wheel leave the vehicle---and that is not good