Terrible noise has me baffled

[02SE]

I've replaced a lot of u-joints over the years, but never on a 2wd 4Runner. The methods for doing so aren't much different from one make to the next. There are some variations in u-joint retention either with Snap Rings, C-clips, or bolt-on straps. The 2wd 4Runner probably uses the C-clip style.

When removing the driveshaft make sure the vehicle cannot roll. After the driveshaft is out, mark the parts with paint so they go back together in the same position in relation to the other parts that they were in before dis-assembly. Otherwise a vibration due to the driveshaft now possibly being out of balance, is likely.

There is some feel involved in getting the u-joints installed so they aren't binding in any direction.

I imagine there are probably lots of how-to guides and/or videos on how to do the job, on the 'net.

If you aren't comfortable swapping them out, a driveline shop should swap them fairly cheaply.

 

[Outrider]

Well, one online vendor shows the u-joints, but one of the brands listed indicate that only the rear u-joint is replaceable, meaning that a new drive shaft must be purchased to get the front u-joint.

I don't know if this is true or not. Anyone else ever dealt with this on a 2wd?

 

[Blitzkrieg]

Remember Blitz's # 1 rule:

Don't overlook the obvious. ;-)

You've already stated it only does it under load, so don't discount that.

Its NOT an engine balance issue. The 3.4 runs like a sewing machine.

But you got a good tip up above. Under load moaning noises are almost always related to a U-joint or wheel bearing issue.

Check the drive shaft first. Get under the truck, grab it and twist and shake. When U-joints go out, they start small. A little bit of play that you will feel in either lateral or torsional slack.

Next up would be the rear axle bearings. Lift each side up and rotate them and pulll back and forth on the bottom and top of the tire. Again, it starts small and gets progressively worse with miles.

 

[Outrider]

I strongly suspect that it's one of the u-joints. I popped the driveshaft loose today. The rear u-joint felt fine in one axis, but definitely had a little bit of bind in the other axis. Binding around center, and freeing up once I got past the bind, in both directions. Didn't want to deal with new trans. fluid leaking out the front, so I didn't pull the shaft all the way out of the trans. to check the front u-joint.

Since u-joints were mentioned, I did strongly suspect them. As a mechanical engineer (a real one - not a booksmart one), I do understand how things work.

I guess nobody has ever dealt with this before on a 2wd version. Nobody has replied to my specific questions about the u-joints. Apparently, unless I am corrected, I have to spend $400 for a new shaft, plus another $20 for a new rear u-joint. Not gonna do that, until this thing leaves me stranded, and I have no other choice.

 

[UARandy3]

I guess nobody has ever dealt with this before on a 2wd version. Nobody has replied to my specific questions about the u-joints. Apparently, unless I am corrected, I have to spend $400 for a new shaft, plus another $20 for a new rear u-joint. Not gonna do that, until this thing leaves me stranded, and I have no other choice.

I had BOTH of my u-joints replaced on my 2wd runner within the last year. I took my truck into a shop to check out a wicked vibration and a "clunk" when shifting into gear. It was definitely the u-joints as indicated by excess play in the driveshaft and the above mentioned symptoms. However, they only replaced the rear u-joint (for w/e stupid reason) and then a few months later my front u-joint started doing the same thing, so I had to get it replaced as well. As far as I know, it pretty much just involves pulling the driveshaft, pressing out the old u-joints, then pressing in the new ones.

Hope that helps. Good luck!

 

[Outrider]

Ok, thanks UARandy3. Good to hear someone else has also dealt with this.

I'm going to order the front & rear u-joints. I'll be getting the type with grease fittings, so hopefully I don't have to go through this again. Worst case, I'm out $50 and a few hours of my time. Best case, problem solved forever.

 

[Outrider]

Update

Just wanted to post an update on this issue. Finished the job this morning, took a test drive, and the sewing machine is back. No more howling resonance, no more felt vibration, and it is as smooth as silk again.

The job was very difficult. Either Toyota tried to simply save a dime here, or a bean counter told an engineer to do something no engineer would ever do on his own - design something that forces owners to take to a dealer after a planned lifespan, because of a lack of serviceability or replaceability. My '99 2WD automatic had neither. Had to surgically cut mine apart, while pressing before and after the cutting with an arbor press. My big, heavy duty vices would not do the job. Took a bunch of very precisely directed heavy force, but I have defeated their way of thinking. Problem saved myself over a grand, too. And now, I can keep these going for the life of the vehicle.

 

[EquineRunner97]

Thanks for the update. That's something I'll have to look out for.