Need to hear what you think.....

[number9]

I have been looking at a 02 Yukon 4x4 for the wife. It has 50k and body/interior/everything looks great. However, it has a slight whine at speed around 50-60mph. It doesn not have any vibrations at all. I put it in Neutral at this speed and let the engine die down and reved it up to eliminate that as the source - the noise is not rpm dependant. I stopped and put 40psi in all the tires (Firestone factory looking tire with near new tread) and weaved from side to side a little and the noise did not seem to change by placing more load on the front tires doing this - I think this eliminates the hubs & tires as source. It *seems* to me it is likely gear/drivetrain noise. However - the noise does not change with throttle - like ON throttle OFF throttle, so it doesn't seem to be ring & pinion noise as I would expect to hear noise change on drive side and coast side of ring gear. It does have the Auto selection transfer case (ie. Auto - 2Hi - 4Hi - 4Low). I put it in Auto and 4Hi while driving and I heard the usual noise that you would hear from doing most any 4x4 that way - increased noise from drivetrain when in those modes.

 

Do any of you have any experience with the noise I am describing? Any issues/problems you may have seen along the way that sounds like this - and if so, what was it? I am getting a really good deal on this Yukon and hate to pass it up, but I would love to have an idea what this noise is. If you have the fan/AC or radio on I don't think you could hear it.

 

What components from T-case forward actually rotate while driving in 2Hi? The noise really doesn't seem to be coming from the rear at all.

 

It turns out a guy I went to highschool with bought the Yukon new and traded it here locally (150 miles from hometown). I called and spoke to his wife a week or so ago and she said they never had any problems with it at all. I am going to call back and speak to him tomorrow, but wanted to ask opinions here as well.

[100R1]

What axle ratioi does it have ?

G80 locker ?

 

I have a 01 Yukon w/ 3.73 & G80 2Wd., I also have around 50K on the 'Kon.

 

I have noticed a VERY slight whine in the rear Diff. I have changed the fluid at approx 20K mile intervals w/ synthetic fluid that meets GM call out.

 

My whine is noticeable around 45 - 50 MPH and only when I maintain a constant speed. When I coast the Whine disappears, when I accelerate you can not hear it, Higher & lower speeds you can not hear it.

 

If it's similar to what I describe, Then it would be attributed to normal wear on the ring & pinion. One Thing I have found out over the years of Owning Rear drive SUV's is that the rear cargo area acts like a amplifier for rear driveline & road noises. Pick-up truck owners don't hear the same noises SUV owners hear. I Once owned a OldsMoBuble Vista Cruiser Station Wagon (even older than the one on "That '70s Show") and even it had a noisy rear end.

 

If what you hear is LOUD then there may be more wrong (low fluid level, Carrier bearings, excessive back lash ring & Pinion)

 

If it's just normal wear on the ring & pinion you can not re-set the back lash. From my past experience with having noisy rear axles rebuilt, It's not worth the money & effort unless you have broken parts to replace. The noise for me has allways come back

 

I have had my Dana rear axle in My '99 Jeep GC rebuilt 4 times due to LOUD WHINE and it still whines like a S.O.B. (only have 92K miles on it!) The Jeep WJ design is great for handling the way they designed the rear with a "A" arm attached to the top of the Pumkin, But the arm transmits all kinds of noises from with-in the rear diff to the body and amplified into the rear cargo compartment.

 

As long as my 'Kon gets no louder than it is, I still consider it quiet. I love my 'Kon!

 

I hope My long winded post helps you out.

[number9]

Yeah, the noise is not loud at all and most people may not even notice it. If the radio or AC was on I am not sure I could hear it. It is not ring & pinion noise like you are descriing with your Jeep. This noise is constatnt and only seems to occur in the 50-60mph range. Your Jeep has noise on the coast side of the ring gear - very typical. I was Manuf. Engineer with Dana at the plant your axles were built and I know the noise was an issue. This noise seems to be a rotational or rolling sourced noise - not dependant on engine speed, load to drivetrain or anything else.

[willieboy]

My 2wd 'Burb does exactly the same thing. Actually, almost all my trucks have done it, except you could not hear it unless you were in the bed and had the topper on. Like mentioned, I only have the noise under constant acceleration, it is in the 50-60 mph range, and it goes away as soon as I am off the gas, and I cannot hear it unless I have the windows up, the AC off, and no radio. My wife never hears it. I think what you have is normal. If it is a good deal I would not hesitate to buy it.

 

That reminds me, it is time to have the diff and trans serviced on the 'Burb...

[SierraCrew]

If you have 50,000 miles and have never changed the rear axle fluid though, its due. I have to change mine quite often in my truck and the noise is a barely audible whine about 45-60 mph, noise reduces when coasting to speed. If it gets bad it will start to chatter upon takeoff like its doing now.

[number9]

Well, I came home today (we had it over night) and removed the front drive shaft and took it for a drive and the noise was gone. Put the shaft back in and noise is back. This leads me to suspect front carrier bearings because the noise doesn't change if the drivetrain is under a load or costing. If it was ring & pinion I would expect the noise to change pitch when ON / OFF throttle as the load on the ring gear would change from the drive side to the coast side. Told the stealership and they dropped price another $1k.

 

I spoke to the guy who bought it new last night and he said he never had any issues with it at all. The body/paint/interior is mint and everything else seems to be fine with it - except for this. As it stands we have a price of about $4-5 lower than any other 02+ Tahoe/Yukon in the 50k miles and less range. The fact that I know the history on this one (where it was bought and who owned it) really appeals to me. So, if I buy it and then spend worst case $1500 (at dealership cause their work has 12month/12k mile warranty) to get front diff repaired I still have less in it than others on market. Thing is.....I have to buy it tomorrow if I want it - it is going to auction on Monday.