aowRS

sawguy,
I hope my additions to your thread are seen as helpful, rather than a hijack...

I removed my original 303,000-mile diff today. Four words: It was not easy. Un bolting the driveshaft was very challenging, but maneuvering that cast-iron lump out of it's hiding place was a real challenge. Luckily a friend stopped by to add some muscle to the process.

My '01 has the electric 4WD actuator, and the '00 diff I purchased was vacuum operated. I unbolted both, cleaned the mating surfaces, spread a film of gasket sealer and attached my actuator to the new diff. Then we heaved the new diff into place and I reattached the drive shaft, steering rack, etc.

I'm waiting on a few dust seals and the bearing tool set before I can move forward. At least that heavy bastard is in place.










Andreas

aowRS

Since sawguy & I appear to be chasing the same drivetrain issue, I wanted to update this thread. Over the last two weeks, I've:

- installed a 40k-mile front differential
- installed a matched pair of 60k-mile halfshafts
- installed new halfshaft dust seals
- installed new differential oil seals
- replaced both wheel bearings/clips/seals (insanely challenging)

The good news: the truck drives as it should & the 4WD works correctly.

The bad news: the growling drivetrain noise/feeling is 100% unchanged....

I'm assuming that the issue may be in the rear axle (or transfer case). I will investigate tomorrow and report back. For what it's worth, both of my front wheel bearings looked perfectly fine at 303,000+ miles.



Andreas

Jomoka

Yeah, those things are surprisingly hard to work with.

sawguy50

I just got back from vacation and listened to the noise the whole trip. Didn't get any worse, but very annoying. I,m in need of an oil change, so I'm taking it in to a dealership next week and going to have them put it on a lift and try to pinpoint the location. I will update when noise is located. Even though it sounds like it's in the front, it might be the rear pinion bearing. I replaced it once already at about 150k. I now have about 230k.

aowRS

sawguy,
I've found the noise! It's my passenger side rear wheel bearing. No question.

Today I placed the truck on four stands in the garage, started it and let it idle in 'D'. It was immediately evident that something was making noise in the rear. Then I placed the stethoscope on various points around the rear axle. The only wheel spinning at idle was the driver's side, and nothing sounded concerning. When I placed the probe at the center of the differential cover, I heard some unpleasant sounds.

But the kicker was when I carefully bumped the speed up to about 50 mph - all of a sudden the rear axle sounded like it was filled with gravel. Very, very obvious. I had my neighbor pop over and keep the speed steady while I again checked with the probe. At this speed, both wheels were spinning. Once I put the probe on the passenger-side backing plate, all doubt was removed. The sound through the earpieces was deafening.

Here's a short video clip. In person, the sound is very pronounced and unmistakable:




Andreas

sawguy50

Glad you found it. I did that to mine and heard nothing.

aowRS

Any change? I've driven around 600 miles since overhauling the front drivetrain and the right rear wheel bearing noise is beyond painful now. I'm no longer driving the truck as of last night.

I ordered all of the parts to do both sides and once again have the use of my friend's 4Runner.



Andreas

sawguy50

Haven't had time to get the truck in yet. Not driving it. Doing some kitchen remodeling for friends down the road and have not got into town yet. Maybe tomorrow.

aowRS

I'm still waiting on my bearings & seals to arrive, so I went ahead and pulled my right axle this morning. Took a quick video to show the state of the bearing. I'd say that I found my problem:


http://www.youtube.com/watch?v=R6f49Qaufk0



Andreas

Jomoka

Don't get too hasty, that bearing still has 10's of miles of life left in it!

sawguy50

Still haven't made it to town yet. We live about 45min from closest decent size town.

aowRS

I received all of the parts today and spent a few hours carefully reassembling/pressing everything. Much of my time was spent double checking all of my measurements for the spacers and for the axle housing seal.

Filled the diff again, bled the right wheel cylinder, and took it for a drive around town.

Quiet as a church mouse. I'll tear the left side apart next week since I'm taking it on a 1,000+ mile drive this weekend...





Andreas

aowRS

I drove the truck more than 1,200 miles since Friday. No drivetrain noise whatsoever. I'm very pleased that's behind me.

Because of the mileage (304,700) I'm tearing the left side apart tomorrow in order to replace that bearing and associated seals.

I think my fastidious measuring of seal depth, spacer position, etc. last week worked - no leaks or gear oil smell.



Andreas

sawguy50

Well, finally got to the dealership today. Told them to use a frame lift and try and determine where the noise is coming from. They instead decided to test drive it to find the noise. Tech came back and said it was the right front wheel bearing. I told him I had just replaced the front wheel bearings. He said maybe you got a bad one. I said what happens if you replace it again and the noise is still there? He said we move on to something else then. I guess I'm going to have to try and narrow this down myself.

aowRS

Yes, either find another shop or investigate further yourself. As you know, I chased a very similar noise, replaced the front diff, halfshafts & wheel bearings only to find out it was my right rear wheel bearing (replaced the left one this morning).

The front wheel bearings are insanely stout - mine were perfectly fine at 303,000 miles..... after I nearly killed myself removing them.



Andreas

sawguy50

When I looked at my old front wheel bearings, they were just as smooth as could be. But too late after the new ones were already installed. Could you hear any wheel bearing noise if you spun your rear wheel by hand?

aowRS

No, because of slight brake drag, and the differential action, I was not able to move the wheel fast enough by hand.

The truck needs to be off the floor on four stands (or on a lift) and idling in D. If it's one of your rear bearings, it should be pretty evident. Spinning it up to 40-50 mph will remove all doubt...

Where are you located?



Andreas

sawguy50

I'm in South Dakota now. Was born in Baltimore

BradFed

Glad I found this thread!

I just purchased my 98, and the guy before me said he had replaced his front differential within the last 6 months, and told me the front-right wheel bearing needs to be fixed. But I can't feel any play on it even using a pry bar against the wheel when off the ground. It seems like he may have been chasing a problem similar to yours.

I'm getting a clicking/clunking that is very distinct under 10 mph. I think mine is coming from the transfer case because I cannot get the 4WD to engage properly. Sounds like I need to go get a stethoscope though and see how much that can help me.

sawguy50

update...Haven't driven the runner for almost 2 weeks now. Took it to the dealer for an oil change and asked if they would put it up on a frame lift and diagnose the noise. Why don't people do what you ask? They took it for a road test and said they thought it was the RF wheel bearing. I just replaced them a few months ago. He said maybe you got a bad one. I said OK, if you replace it and that's not the problem, then what? He said we move on to something else.
I again jacked it up on all 4's yesterday and at 40mph in 4wd you can hear noise and a thumping ( shakes the whole truck ). I don't dare climb under the vehicle when in gear and use a stethescope when only supported by jacks and jackstands. I did however turn the front right tire and hold a long metal rod to the transfer case and heard grinding noise. This was in 2wd and the front diff driveshaft was turning. WTH?