Whine from front during acceleration/deceleration (1 Viewer)

[Perveance]

Hi All,

I recently bought 2006 GX470 with 107K miles on the clock. Couple days after noticed a whine from tranny/Transfer case area during acceleration/deceleration. I've replaced fluids in transfer case, tranny (drain and fill) and differentials, but it hasn't made any difference. Fuilds in diffs and TC were pretty pretty dark, but not too bay. Though I assume previous owner had never changed them.

I've noticed that the whining noise is proportional to speed, and as the car accelerates, whine frequency gets higher. And it doesn't reset on gear changes. It's most noticeable at around 20-55mph and when car is cold. As I said, I hear the whine when slowing down too. If I shift tranny to N it doesn't stop the whine, but if I also shift TC shifter to N, the whine disappears.

Please help, it's very annoying. What could be the problem?

Thanks in advance!
Mike

 

[GXO]

Hmm...tcase holds the load from the wheels...either a bearing in the tcase or (more likely) you have a wheel bearing telling you it needs help.

 

[Perveance]

Thanks for your reply, DanKunz.

One more note, I checked the wheel bearings for any play when we were changing fluids in the T-case a couple of weeks ago, and there was no play. Additionally, the noise pretty much disappears when I release the throttle pedal or maintain low RPMs. The noise is mostly heard during acceleration (Engine revs at least 2K+), or decelerations. I'd characterize it as high pitched whine, sounds a little bit like the sound of those electric buses

 

[little_joe]

I am unclear: does the noise exist if you, for example, leave the GX in P or N and rev it? or is it only while moving? Just trying to rule out engine accessories (AC compressor, alternator etc) vs drivetrain.

 

[Perveance]

The noise exists only while moving. The frequency of the noise is linked to the speed.

 

[Matsui]

I experienced similar issue when my alternator was going bad. The engine made a whiting noise especially during acceleration. You may want to get the battery tested for voltage. I ended up replacing the alternator and the noise went away.

 

[Perveance]

I experienced similar issue when my alternator was going bad. The engine made a whiting noise especially during acceleration. You may want to get the battery tested for voltage. I ended up replacing the alternator and the noise went away.

Ok, I'll check the battery.
So my noise exists only while moving, if I just rev the engine at N I can't hear the noise. Was your alternator noise linked to engine revs or to speed?

Btw, the battery on my GX was replaced in 2015 (know it as the previous owner provided a pile of service records). Alternator was replaced in 2014 at 85K with probably aftermarket one.

 

[MontcoGx]

I have a 2006 with similar miles and a similar issue. I can almost feel the noise / vibration like bass from a stereo. It doesn't fluctuate in mine - more of a constant drone-type of thing that goes away at slower speeds and happens intermittently.

 

[Placemotorsports]

Try turning your steering wheel sharply at speed. If the sound changed, you have a bad wheel bearing.

 

[Perveance]

Try turning your steering wheel sharply at speed. If the sound changed, you have a bad wheel bearing.

Tried it this morning. The sound doesn't change at all, so it's probably not wheel bearings. Additionally, the sound is pretty high-pitched, and can be heard mostly during accelerations (RPMs should be more than 2000) or faster deceleration. I can't hear the sound after speeds of 60mph or when I stop accelerating.

 

[MontcoGx]

I found this earlier - http://alflash.com.ua/avtovideo/2005l/L-DL001-08.pdf

I am unsure of what is going on. I live in PA so when it warms up later this week, I am going to be crawling underneath for a look.

 

[Perveance]

I have a 2006 with similar miles and a similar issue. I can almost feel the noise / vibration like bass from a stereo. It doesn't fluctuate in mine - more of a constant drone-type of thing that goes away at slower speeds and happens intermittently.

Hi MontcoGx. Thanks for your input, however, your sound is different from mine. My sound's pitch is linked to the speed. It's pretty quite and high-pitched, and may be hard to replicate for a technician in a shop, but I know exactly how to replicate it. Also, my sound is a bit similar to the sound of driving in reverse on an older car with manual transmission, except that my gx's sound is much more quite and more high pitch. Really annoys me sometimes

 

[Perveance]

I experienced similar issue when my alternator was going bad. The engine made a whiting noise especially during acceleration. You may want to get the battery tested for voltage. I ended up replacing the alternator and the noise went away.

The battery check game out OK. Looks like it's not alternator or battery related.

I assume the problem might be in the drive train. Does anybody have any idea how to figure out whether drive shafts or the transfer case or tranny is the culprit?

 

[GXO]

Secondary air pump possibly. Driveshaft...cdl and remove front and drive it. Then put it back and remove the rear and drive it.

 

[Perveance]

Secondary air pump possibly

Thanks for your reply. How do I trouble shoot the secondary air pump? Is it the EGR flow? Wouldn't it throw some engine error code if it had a problem?

Driveshaft...cdl and remove front and drive it. Then put it back and remove the rear and drive it.

Got it, will do that this weekend. So what do I expect to observe. Say if the whining noise is still there with either of the driveshaft removed, then it's probably problem in the transfer case, right? And if I remove the front driveshaft, and the noise disappears, while it wouldn't disappear with the rear removed, then it's probably the front driveshaft needs to be addressed, is that right?

Btw, I know my rear driveshaft has the infamous clunk issue. Greasing it doesn't help.

 

[Perveance]

Any ideas or hints on the next steps after removing the driveshafts and driving with only one connected? What do I look for?
And how do I proceed?

 

[GXO]

I would test by removing the rear first. Lock your CDL and remove, drive and listen for noise. If you have the clunk and you can't stop it with grease it could be ujoints back there.

 

[Perveance]

Thanks DanKunz! Stupid question, why do I need to lock CDL? Is it because if I don't do that, then all the torque will go to the removed shaft?

 

[Perveance]

One more question, to get rid of the clunk do you advice replacing the center of the u-joint and the entire u-joint,
Or rather which one of these two I should replace?
(1)
Universal Joint (U-Joint) - Intermediate Shaft - Rear
(2)
Universal Joint (U-Joint)

 

[GXO]

Correct... Won't move.

I would just order the updated drive shaft part. Most places won't balance or do u joints on GXes