Rear differential whine?

I need to hear from all the people who had a loud roar/whine between 55-70 when you apply throttle. I've read several of the posts but they seem to be from '04 and older. With that in mind, I don't know how many of these people are still members of this forum.
I have a loud roar under throttle between those speeds, at first I thought it was tire roar but letting off the throttle makes the noise disappear and then you only have roof rack noise, tire roar and wind noise. Did anyone get that resolved? If you've seen my posts, you know I've recently done both the trannsmission fluid change and front/rear axle fluid changes, but the roar is still there. The VX is not lifted, doesn't have oversized tires and the roar is definitely from the rear.

I have had a roaring noise that comes from my rear end for a while now. And no, not from eating too many beans. :)

The problem I have though, is after I start up, I hear a weird roaring/groaning sound that seems to come from the rear end, and then goes away after a few seconds. I can't imagine what the noise could be. I plan to do my diff fluids soon, so I will see if that sound goes away then.

Bart

Ever since I lifted I get a weird whine/roar from my driveline somewhere sounds like it is from the rear, but I only get it when I let off the gas over 55 mph or so, does not happen at lower speeds, does not happen when accelerating..... My dad seems to think it might be vibrations from the crazy tread pattern on the new tires, but I remember noticing it after the lift before the tires went on, I thought it was simply wind going underneath the VX different than normal, sorry no help, but I experience this kinda. Could this be from changing to full synthetic diff fluid? Do we need thicker fluids?

The rear dif does require limited slip dif fluid. At least that’s what they charge me for when I get it serviced.:rolleyes:
But you probably have a locker.:p

Check your U-Joint. My vehicle would would rattle and shimmey when I got to higher speeds. I took it to an ex-Izusu dealer. The mechanic said it was my tires separating from the tread. I then took it to three different Discount Tires to have them check the tires. They said it wasn't the tire, but it was out of balance. After getting their top of the line wheel balance, the problem was still there. I then took it to a Izusu dealer which is still in business. He took it for a drive, it rattled, he let off the gas, and then there was no more rattle. He said........"yep, that's a bad U-Joint.

He changed the U-Joint, and it mhas been the smoothest drive my VX has ever had. Check that out......that my be it.

Peace.
Tom
012009

good suggestions, I know it's likely not tire related as I had this issue when I first got the VX, then I replaced all 4 tires in the hopes of quieting the noise (which, once again I thought was tire roar) and still had the noise, I've also rotated the tires since I replaced them
Just a reminder, I only get it on throttle and it goes away when I lift off the throttle, also, it only happens at highway speeds

I got the same noise after the lift. I think it's just the driveshaft + thin floor. I also notice it more with the skid plates on - they probably reflect the sound back.

Check your fluid levels - replace axle oil if its been a while - as well as the TOD case.

Check the U-joints (see if there's any play in the drive shaft when you try to turn it by hand...)

Check your emergency brake tension

Check the rear rotors - discs for corrosion
http://www.vehicross.info/gallery/da..._rotor_BAD.jpg

Check the inside of the rear rotors for a loose drum pad (E-brake) or worn pad.

If all else, maybe rear bearings....

Also, meet up with a fellow VXer and try their ride to see if it's they have same noise....

Good Luck.

Quote:

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Originally Posted by Kenny

I got the same noise after the lift.
Check your fluid levels - replace axle oil if its been a while - as well as the TOD case.

Check the U-joints (see if there's any play in the drive shaft when you try to turn it by hand...)

Check your emergency brake tension

Check the inside of the rear rotors for a loose drum pad (E-brake) or worn pad.

If all else, maybe rear bearings....

Also, meet up with a fellow VXer and try their ride to see if it's they have same noise....

Good Luck.

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OK, I've heard U-joint twice now. I will try that first. The tension on the e-brake is NOT what I'd like it to be. You basically have to yank it all the way up to have it hold and I just prefer it to not be that drastic. I did replace the oils recently but not the TOD oil. I will have to read up on how to do that.

you can also try greasing the driveshaft, i just did all my grease points (3 on the drive shaft and 4 suspension bushings that i added) quieted my vx down quite a bit

Well, a u-joint tends to pop when it is acting up, wearing out. The ring and pinion gear will give you the whine, and yes I have it too, with no lift other then cranking the torsion bars to get the 285's to fit.

OK Rowhard, please educate me. What do you do if it is the ring and pinion gear? Is this something that just needs to be replaced or can it be serviced?
These are all good, I need to make a mental note of all that I need checked as I'm betting the local Isuzu mech will say all appear normal :(
U-joint, e-brake, ring and pinion

Quote:

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Originally Posted by etlsport

you can also try greasing the driveshaft, i just did all my grease points (3 on the drive shaft and 4 suspension bushings that i added) quieted my vx down quite a bit

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I think you are right on. That was origonialy my 2nd thought so I tried that and it fixed my 'bad vibrations' for about a week. So there are 2 things replacable in the area the u joint and something else my dad said went out on his toyota 4x4 back in the day. How big of a deal is the u joint? How much time? If too hard price?

I believe it's the U-Joint (+) and the Yokes (U) Does anyone know the specs for our U joints? I'd rather buy aftermarket from a Driveline specialist than get a factory set.

I used to work at a Trailer (semi) repair shop when I was a teenager...

here are a few threads from earlier days:

http://vehicross.info/forums/showthr...ht=ring+pinion

http://vehicross.info/forums/showthr...ht=ring+pinion

http://vehicross.info/forums/showthr...ht=ring+pinion

http://vehicross.info/forums/showthr...ht=ring+pinion

U-joints will cause the clunking type sounds, espically when going form drive to reverse. Gears, make the whining sound

thanks Rowhard, if you know off-hand, I would appreciate knowing if the ring and pinion set would need to be replaced or just serviced? Also, would the Isuzu mech know it by that name or is there a more proper term? I'm at work and can't spend too much time running through threads. If you don't know, that's ok, I can read them tonight.

Joe, I'll be honest, it could be as simple as a backlash adjustment that you can eliminate with shimming. BUT, it takes special tools for measuring and knowing what the heck your doing. Yes, any mechanic with the training, tools and spec's could do it, just finding one that would do it. Most just want to replace something, not repair it. And yes that is the name we call it. The British I believe call the ring gear a crown gear, can't remember what the call the pinion gear off hand.

Joe, I'll be honest, it could be as simple as a backlash adjustment that you can eliminate with shimming. BUT, it takes special tools for measuring and knowing what the heck your doing. Yes, any mechanic with the training, tools and spec's could do it, just finding one that would do it. Most just want to replace something, not repair it. And yes that is the name we call it. The British I believe call the ring gear a crown gear, can't remember what the call the pinion gear off hand. If you have the workshop manual downloaded into your home computer, it starts on page 334

Thanks as always rowhard. Now, I'll be honest. There ain't no way I'm messing with this thing myself :)
Shoot, this is one of the few parts on a car I have no idea where it's located. I'm certainly now going to try and fiddle with it solo. Appreciate the encouragement but the tranny job was enough for me for the time being.
I will have to deal with the TOD fluid change though sometime this month. I did everything else it seems except that one.
OK, let's see how things go with the Isuzu place. The last time I had them check for the roar the mechanic said he didn't hear anything abnormal. Sorry, there's a definite roar under throttle at certain speeds. I hope we don't play this game again...

Konichiwa from Japan.

I have an automatic 3.1 litre VX I have the same problems with a clunking sound when going from Park into Reverse/Drive also travelling at a low speed the engine sounds like it's revving out! The whine sound only seems to occur when the VX is in low gear then subsides after. Is this normal? Or should I be checking the UV joint and dif oils?

Any advice appreciated

Jetz

Gear Noise
Gear noise (whine) is audible from 32 to 89 kmlh (20 to 55 mph) under four driving conditions.

1. Driving under acceleration or heavy pull.

2. Driving under load or under constant speed - -

3. When using enough throttle to keep the vehicle from driving the engine while the vehicle slows down gradually (engine still pulls slightly).

4, When coasting with the vehicle in gear and the throttle closed. The gear noise is usually more noticeable between 48 and 64 km/h (30 and 40 mph) and 80 and 89 km/h (50 and 55 mph).



Bearing Noise
Bad bearings generally produce a rough growl or grating sound, rather than the whine typical of gear noise. Bearing noise frequently “wow-wows” at bearing rpm, indicating a bad pinion or rear axle side bearing. This noise can be confused with rear wheel bearing noise.



Rear Wheel Bearing Noise
Rear wheel bearing noise continues to be heard while coasting at low speed with transmission in neutral.
Noise may diminish by gentle braking. Jack up the rear wheels, spin them by hand and listen for noise at
the hubs. Replace any faulty wheel bearings.



Knock At Low Speeds
Low speed knock can be caused by worn universal joints or a side gear hub counter bore in the cage that is worn oversize. Inspect and replace universal joints or cage and side gears as required.



Backlash Clunk
Excessive clunk on acceleration and deceleration can be caused by a worn rear axle pinion shaft, a worn cage, excessive clearance between the axle and the side gear splines, excessive clearance between the side gear hub and the counterbore in the cage, worn pinion and side gear teeth, worn thrust washers, or excessive drive pinion and ring gear backlash. Remove worn parts and replace as required. Select close-fitting parts when possible. Adjust pinion and ring gear backlash.
MY2000 Isuzu VehiCROSS Workshop Manual Page 1


*****Just to let you know I simply printed the part in discussion and then scaned it into my computer using a Text converter, I didn't think it would be that easy but it was.*****

So I either have:
-bad pinion
-bad rear axle side bearing
-worn rear axle pinion shaft
-worn cage
-excessive clearance between the axle and the side gear splines
-excessive clearance between the side gear hub and the counterbore in the cage
-worn pinion and side gear teeth
-worn thrust washers
OR
-excessive drive pinion and ring backlash

oh that really helps, I don't even know what half of those things are!!!!! LOL
Mine is not that bad and certainly only happens when I get OFF the throttle, so I might live with it for a while. We will see. Any thoughts?