: Humming/groaning noise coming from front differential



box986
08-17-09, 09:41 PM
Noise is definitely coming from inside the diff as I raised the truck on 4 stands and had a helper put it in gear and get up to 40-50 mph while I was underneath. Noise is more noticeable during acceleration in the 25-50mph range. Will bearings solve the problem or is that just a band-aid fix to the real problem which are the gears? How big of a job is it to change the bearings? Where can I get an entire assembled differential if I go that route? Sad part is that my EXT has only 20K on the clock. Tried synthetic but that didn't help one bit.

Thanks!

Al

03 EXT 20K

luxurylife33
08-18-09, 12:32 AM
according to my carfax, my front diff was replaced under warranty at 14k miles

EDIT: :bigroll: :bigroll: :bigroll: :bigroll: :bigroll:

oldworld
08-18-09, 12:04 PM
Is this the proper way to detect exactly where the whine is coming from?
Are there different types of whine for the front diff, transfer case and wheel bearings???

THANKS

box986
08-18-09, 05:36 PM
Is this the proper way to detect exactly where the whine is coming from?
Are there different types of whine for the front diff, transfer case and wheel bearings???

THANKS

Not sure what the proper way is, but getting under the car in gear was the definitive way for me. In the shop they probably use a mechanic's stethoscope. Wheel bearings would be a different noise and would be more evident while turning putting more stress on the bearing.

box986
08-18-09, 05:47 PM
according to my carfax, my front diff was replaced under warranty at 14k miles

EDIT: :bigroll: :bigroll: :bigroll: :bigroll: :bigroll:

I even had an extended warranty on my '03 but that expired last November, figures...

luxurylife33
08-18-09, 05:57 PM
That sucks! Did you ever change the fluid on it? I changed mine when I first bought it in October and it was BLACK as shaq. I recently changed it again (about 10k miles later) and it was already BLACK again.... apparently you got to really keep up on the fluids with these front diff's. The rear diff was still clear after 10k miles! weird.

box986
08-18-09, 08:59 PM
That sucks! Did you ever change the fluid on it? I changed mine when I first bought it in October and it was BLACK as shaq. I recently changed it again (about 10k miles later) and it was already BLACK again.... apparently you got to really keep up on the fluids with these front diff's. The rear diff was still clear after 10k miles! weird.

The rear diff is 75W-90 synthetic from the factory, front diff comes with conventional 80W-90. I did not change over to synthetic up front until I heard the noise at 20K. I hope it is just the bearings but the noise appears to be coming from deep inside. I can buy a TIMKEN bearing set for $140 on ebay & might try that first but will get a 2nd opinion from a real mechanic before I go any further. Not sure where I can get a ring/pinion set besides the dealer?

box986
08-28-09, 06:04 AM
UPDATE: I removed the differential (easy job) & brought it to a mechanic that specializes in differentials/transfer cases.

One of the pinion bearings was shot and causing scorching to the race. He said the original pinion bearings may have been installed a little too tight based on the tightness of the new bearings when they went it, so he changed all the bearings and backed off the adjuster a little bit. Teeth/pattern looked fine on the ring/pinion. He still couldn't believe that this had to be done a truck w/20K miles.

Bearing kit plus labor: $420. Would have been $620 if I let him remove/install the diff. He would only warranty the work if I assured him I would put in synthetic.

box986
08-30-09, 05:56 PM
Well, it was harder installing the diff than it was removing. Had gravity on my side when removing & had to take the steering rod off the pitman/idler arms, which I didn't have to do when removing? Would have been a lot easier if I had a 2nd set of hands. Used Amsoil Synthetic gear lube. I am happy to say no more noise!!

sk7
08-30-09, 06:50 PM
Great outcome! I know what you mean about the extra set of hands! But those come at the expense of lotsa blablablabla (gf), so sumtimes I gotta weigh in advantages vs disadvantages, and I end up doing the work by myself lol! I'm also going to switch over to amsoil in my front diff as soon as I stick the winter tires on. It will have been about 5000 miles since I changed the oil, can't wait (well not really) to see if there's any metal shavings on the drain plug. Can you post where u had the diff rebuilt for other members in your area? Thanxs.

box986
08-30-09, 07:51 PM
http://www.merchantcircle.com/business/Power.Train.Inc.973-772-7900

973-772-7900 (John) Nice work, quick turnaround.

box986
09-01-09, 09:15 PM
Forgot to mention, the place is in North Jersey (Bergen County)

smelly$cat
09-02-09, 04:19 PM
"I raised the truck on 4 stands and had a helper put it in gear and get up to 40-50 mph while I was underneath."

This takes balls to do in and of itself..... Not sure if I could do that.

Good reminder to get my fluids changed and hope for the best though.

----




Noise is definitely coming from inside the diff as I raised the truck on 4 stands and had a helper put it in gear and get up to 40-50 mph while I was underneath. Noise is more noticeable during acceleration in the 25-50mph range. Will bearings solve the problem or is that just a band-aid fix to the real problem which are the gears? How big of a job is it to change the bearings? Where can I get an entire assembled differential if I go that route? Sad part is that my EXT has only 20K on the clock. Tried synthetic but that didn't help one bit.

Thanks!

Al

03 EXT 20K

zerocarpileup
09-02-09, 06:11 PM
Yea...... that took major balls to do.

box986
09-07-09, 06:47 PM
"I raised the truck on 4 stands and had a helper put it in gear and get up to 40-50 mph while I was underneath."

This takes balls to do in and of itself..... Not sure if I could do that.

Good reminder to get my fluids changed and hope for the best though.

----

yeah, my neighbor looked at me like I was nuts.

make sure they put synthetic in, even though the manual says synthetic only for the rear diff

WSLN 6
09-08-09, 03:00 AM
I am going through the same garbage with my 03 ESV. Front diff was completely rebuilt about 14K miles ago as well, now under light load there is load "whirring", no clunking noises yet. The fluid was nasty with a big cluster bomb of metal on the drain plug. Brutal.

auberypn
11-12-09, 11:25 PM
I am having also some kind of a noise,but was told it might be the axle as well,not sure,but i replace the bearings,put new tires on,stillwouldnt go away. do any one how the wheel on a 2003 ext awd really spin,mine seems to be spinning weird and are they any sensor to the transmission outside that control how it turns. I jack it all up,put it in drive, and the front spin sometimes one wheel,and the back one wheel then no wheel it seems to be all over the place,or maybe thats how it works.need help. thanks

auberypn
11-16-09, 12:07 AM
Fellows,i am experencing roaring sound comming from the front i beleive,but had my bearings changed. My 2003 ext as been faithful for about five years;so the spending as now began? I jack the truck up,but amazing didnt hear any noise,and also was supprise to see how the wheel were rotating,sometimes one of the front spin then the back spin and stop it seems to be all over the place. Could someone informing me as to how the wheel should spin when in drive,and is there any button to change from two wheel to (awd). I beleived my back wheel shoud be the one in progress when the vehicle in. progress. thanks guys looking forward .

WSLN 6
11-16-09, 09:37 PM
I got mine fixed. The groaning in the front was being transferred from the rear diff that was toast. Try removing the driveshaft going to the rear diff and see if the noise goes away.

auberypn
11-21-09, 10:45 PM
I am a handyman,do u think i can do it myself? whats recomended.

sk7
11-22-09, 04:29 PM
Here's some general info about the AWD system from the service manual.

Transfer Case Description and Operation

http://i438.photobucket.com/albums/qq102/sk7_1969/TC1.gif

The NVG 149 RPO NP3 is a single speed, single mode transfer case. The mode is full-time all wheel drive. It has a planetary differential gear set that splits the torque, normally 38 percent to the front wheels and 62 percent to the rear wheels.

The NVG 149 utilizes magnesium housings. Proper fasteners, brackets, and fill/drain plugs must be used to prevent galvanic corrosion. The planetary differential uses the carrier (6) as the input. The annulus gear (4) connects to the rear output shaft (5) and rear wheels. The sun gear (3) connects to the front output shaft (7) and front wheels through the chain (8) and sprockets. The viscous coupling (2) consists of a sealed housing filled with a high viscosity silicone fluid and thin steel plates alternately splined to the inner and outer drum. The inner drum is connected to the input shaft (1), and the outer drum to the sun gear (3). Whenever there is a speed difference between the front and rear wheels, the inner and outer plates of the viscous coupling spin relative to each other and the silicone fluid provides resistance. The resistance was tuned to be high enough to bias power quickly to the wheels with traction, and low enough to prevent binding in a tight turn on dry surfaces. This is the most common way the viscous coupling is activated, the shear mode. If the speed difference is high, the coupling can lock or hump. This "hump" occurs when the heat generated, expands the fluid inside the housing, changing the fluid dynamics between the plates. This results in pressure between the plates, forcing them into contact with each other, similar to a clutch pack. In the hump mode, the coupling can bias torque 100 percent to one axle, if required. Situations requiring this are extreme such as backing up a steep gravel grade or climbing over off-road obstacles. The viscous coupling is not serviceable; it must be replaced if defective. This is because each viscous coupling is calibrated for optimum vehicle performance for both the shear and hump modes. If the viscous coupling is in the "hump" mode too long, severe damage will occur. To prevent damage to the viscous coupling, DO NOT:

Tow with only two wheels down
Drive without one propshaft
Drive with a "donut" spare tire for an extended period of time

Power Flow - No Wheels Slip

http://i438.photobucket.com/albums/qq102/sk7_1969/TC2.gif

During normal operation, 100 percent torque is delivered to the input shaft (1) from the transmission. The torque is split to 62 percent to the rear output shaft (2) and 38 percent to the front output shaft (3), by the planetary differential. Because there is not a loss in traction or slip in the front or rear wheels, the viscous coupling is locked in place and there is no "shear" mode or "hump" mode involved.

Power Flow - Front Wheels Slip

http://i438.photobucket.com/albums/qq102/sk7_1969/TC3.gif

When traction is lost at the front wheels, the viscous coupling works in conjunction with the differential to bias the torque more to the rear wheels. The rear torque goes higher than the 62 percent, and up to 100 percent torque to the rear output shaft (2). The torque at the front output shaft (3) is lowered from the 38 percent, to as low as 0 percent torque.

Power Flow - Rear Wheels Slip

http://i438.photobucket.com/albums/qq102/sk7_1969/TC4.gif

When traction is lost at the rear wheels, the torque is biased to the front wheels. The torque to the front output shaft (3) goes higher from the 38 percent, up to 100 percent torque. The torque at the rear output shaft (2) is lowered from the 62 percent, to as low as 0 percent torque.

Customers may have concern that the transfer case is not operating properly because one set of tires spun for a brief period. It is normal for one set of tires to spin until the viscous coupling engages.

Turning off the traction control switch, if equipped, enhances the function of the viscous coupling. The viscous coupling, as described above, engages by heat. Allowing one set of tires to spin or slip for a brief period will generate heat in the viscous coupling. The engine speed should be kept at a constant speed during the brief spin of the tires. Pulsating the engine speed or hard acceleration will not allow the viscous coupling to operate properly.

whosurpopi
11-24-09, 04:40 PM
My 03 seams to be sending all the power to the front tires, causing them to spin with less then full throttle. The right tire seams to get more use then the drivers side, but I never feel the back tires spin.