Chirping noise that goes away in 4 wheel drive...

[joemcc]

Hi again,

Time to address my next issue. I have a chirping noise while moving only when in 2 wheel drive. When I switch to "auto" or "4x4" it goes away. It seems to be on the drivers side and starts at about 3-4 mph and gets slightly louder as I increase speed. I replaced the hub a few months ago and it started before that, just not as loud. I'm thinking it is the CV joint. I assume the drive shaft turns at all times (even when not in 4x4)???

Also, If you noticed my other post...getting a vibration in 4x4...seems like a CV.

Anyway, remfd shaft at Napa is only $60.00, but thought I would ask on here.

Take care,
Joe

 

[The_Roadie]

The CV shaft rotates all the time no matter what mode you're in. There is no disconnect in the hub. So it can't be that, unless the shaft is bad and the torque goes in different ways through the shaft in 2WD versus 4WD mode.

My first guess would be a differential issue. How many miles, and have you ever checked the fluid level or changed the oil? In 2HI, the outer gears and spider gears normally rotate, but the carrier does not. Thus the intermediate shaft that goes through the oil pan could be met with a dry/out of lube disconnect assembly on the passenger side of the oil pan, and that could be your noisemaker. Believing GM's lie that it is a "lifetime" lubed and sealed assembly has cost many folks $500-900 for replacements, but you don't think the noise is from the passenger side?

The front driveshaft from the transfer case to the front diff does not normally rotate in 2HI mode.

 

[joemcc]

I checked and recently replaced all the fluids. It does seem to be coming from the driver's side. The rig has about 130k miles. The fact that I now have a vibration when in 4x4, similar to when the CV joint went out in my toyota, leads me to think it's the problem. I just wish I knew for sure.

There is far too much ice this morning to jack the rig up and spin the tire but I will try that soon. Then again, this could be enough difference in the angle to change the sound.

When my wife gets home I will let her drive and I will listen from the passenger side too.

If I drop the hub by releasing the upper ball joint and removing the axle nut (and tap the end of the shaft), will the shaft simply pull out on the drivers side? I cant find a "how-to" on the drivers side. (I found one...doesnt look too bad)

joe

 

[The_Roadie]

There is a circlip on the inner end of the splines, and that can't be pulled on. You need an impact to get it out. Most folks use a long drift punch, short piece of rebar or other metal at a slight angle on the curved edge of the tripot joint. The drive's side is lubricated by diff oil, so it's usually easier than the passenger's side. It often takes a 3-5 pound sledge whack or three to get it out. Prying is not enough of an impact to work reliably, although some folks have reported success with pry bars between the diff and the tripot joint cup.

If you pull on the shaft itself, the tripot joint comes apart because that's there the slip length adjustment is for the way the CV shaft has to change length as the suspension cycles up and down. They make a fork foot for slide hammers that can do it all without banging from behind, but almost nobody has bought these because the membership here is ....let's say.....excessively.....frugal. Yah, that's a good term...frugal.

 

[joemcc]

Ok, I jacked up both sides and spun the wheels as fast as I could. The passenger side was quiet...and the driver's side had some clicking in the inside knuckle. I couldn't get it to chirp...but that could be due to the angle on the shaft and no load on the joints.

Should I start there?

Thanks for your help!

Joe

 

[The_Roadie]

As long as you're sure it's the inner CV joint and not inside the diff, definitely buy a shaft. Many of use use Cardone new (not reman) units, for $50-60 from Rockauto or a bit more from the local parts stores. There are others for less including good quality remans out there on Ebay or Amazon that others have personal experience with. (I don't)

 

[joemcc]

Ok, not convinced it is the CV and thinking it might be the disconnect. Since it chirps when not in AWD or 4WD do you think it's the actuator not fully disingaging? I figured I might start with that and pull it off when the weather improves.

Also, I don't think they are related but the code on my ABS/Stabletrack says speed sensor. The bearing is tight...so I'm thinking (if it can be done) just replace the speed sensor.

Joe

 

[RayVoy]

Joe, I missed your original posts, so I'm slow getting to the party; have you considered a rear driveshaft u-joint?

When in 2wd, the rear shaft must handle all of the torque, when in 4x4, the torque is shared.

I'm thinking it might be the front u-joint on the rear shaft.

 

[joemcc]

Not a bad idea...will check it out.

Joe, I missed your original posts, so I'm slow getting to the party; have you considered a rear driveshaft u-joint?

When in 2wd, the rear shaft must handle all of the torque, when in 4x4, the torque is shared.

I'm thinking it might be the front u-joint on the rear shaft.