Hello
The front drive shaft is always spinning even when the 4X4 is not engaged so I would have that checked for balance as well as the rear shaft, check in the phone book for shops that do drive shaft balancing in your area, just changing the U joints will not cure an out of balance drive shaft, drive shaft balance issues are a very common source of this type of vibration. The other source of a vibration like this is the transfer case itself can cause vibration in the drive line at highway speeds so don't overlook that as a possible cause of the vibration.
I would be inclined to look at the transfer case and have the rear drive shaft balance checked by a driveline repair shop.
I am leaving for the 4th of July weekend so I'll answer any and all questions on my return Tues the 5th of July or sooner if possible.
Happy 4th of July from emissionwiz
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I tolk with my techincian and they said that exist the possibilitie of installed the
wrong U-joint on the rear of the driveshaft... are you check this?
Apparently your rear driveshaft yoke could been splayed open and the U-joint
can slide from side to side in the joint and cannot be perfectly
centered. The mechanic said that while he had the driveshaft off, he
noticed noises and excess play indicating that the pinion bearing in the
rear differential was failing. He recommended the rear yoke
replacement plus the rear differential rebuild, particularly since this Suburban has 200K miles on it.
Check, test it and keep us updated.
A couple of things come to mind. Have the wheels and tires been balanced properly? What kind of kind of tires (i.e. oversize, all terrains, low profile, "cheap") ? Have the wheel bearings been inspected for damage? It sounds like a lot of other things have been looked at but let's go back to basics to make sure we cover everything. Let me know.
With a tire issue, you can have tread which causes a drone but only on the road. i belive you might be saying that this also occured stationary? With wheel/s up? If so you would be correct in that response towards the tires and bearings. How about front axle joints? Have the rear axles been removed and inspected, rear cover removed from the differential and gears inspected? Does the steering vibrate, feel it in the floor, drone while driving? Are these factory size tires? Trying to get the most accurate picture I can. I am leaning towards a worn rear differential. Do you ever use the t-case?
Does it change in pitch whether you are accelerating or decelerating?
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Have you looked at your wheel bearings for scoring? It sounds like one or more of your wheel bearings is seizing and therefore at high speeds is resonating more than at low speeds. I would pull the bearings and make sure they are not scored and that the lube is still maintaining the thick viscosity required in order to keep them lubed. Look for black marks on the bearings and verify the races do not have any scoring, pitting or cracks. This is the only constant, based on your description, that makes any sense. The problem is know which bearing it could be. I would obviously start with the rear as this is the primary running wheel, 4X or 2X.
The problem I have with this is initially I thought maybe the driveshaft was not necessarily not bent, but out of balance. What lead me away from this was you said that if you take it out of gear it still vibrates, but I did not see it was at over 55. I would not refine my answer as to the balance of the driveshaft. On the shaft you will see little metal weights, similar to the ones you see stuck on the inside of a Mag Wheel. I believe that as the shaft is rotating it is like a pencil that has tape on it. The heaviest side is where the pencil will rest. Pull the shaft out, rear in this case as this is the load bearing shaft and you are not reporting a shimmy from the front end. You can take the shaft to a shop that balances shafts and they should be able to find the low spot on the shaft. Unless you really torqued the hell out this pulling something the vehicle is not rated for I don't think the shaft is bent. Besides, you would see a bend if you had it on a lift because a bend of that nature would make the shaft look oblong when it was moving.
Can you tell from which portion of the truck the sound is coming from?
HOW ABOUT THE DRIVESHAFT CENTER SUPPORT
i have a 2000 ls surburban with the auto 4 wd and i have had a heavy vibration, over 50, that increases with speed to that around 75 the entire truck seems to shake up and down 3/4 of an inch or better. I have replaced the following: all ball joints, all tie rods, idler arm and attachment, pitman arm, both front wheel berings, all u joints in the driveline, the rear axle, 2 sets of NEW tires which has been removed and rotated on the factory aluminum rims and then rotated tire and rims front to rear and have had no change in this vibration. oh, and dont forget the 400.00 per side NIEUMATIC rear shocks and new front shocks. everything in the driveline functions correctly and the vibration does not care if the truck is empty or fully loaded towing an 10 ft trailer (also loaded). any suggestions
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Have you had all the wheels balanced? Have you checked for a bent axle?
This could be a warped or bent axle, warped wheel, unbalanced wheel, axle bearings, or even a busted transmission mount, we can rule them out one by one if need be.
If it happens with drive shafts out it would more than likely be a trans issue
Have you had the flywheel and converter of pressure plate checked for balance?
since you have the same issue with the shafts out, it would most likely be a trans issue
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I'm thinking what you are hearing is your torque converter, the input to pump is worn and your getting a a bit of converter shake. May sound a bit more like a whining than a hum. Sorry, transmission is getting tired. Hope this helps Fix Ya up.
My two guesses, based on what you have written, are tire balance (or tires, period) or a wheel bearing.
tried to help by considering another possibility-if a tire or wheel is OFF the vehicle, then it is not an issue-but if it is ON the vehicle, and spins, it's balance can certainly have an effect-and a wheel bearing, unloaded (in the air with no weight) might not manifest it's effects in the air...but I'm only going by what YOU have written, so thanks for the glowing review. good luck.
Well, it's not my truck, but if it were I'd waste another $40 or $50 tops balancing the tires-just to be sure. Then, I guess you could remove the engine and trans and balance and blueprint both components-you installed new U-joints and a drive shaft, I'm SURE they are perfect...good luck.
well sounds like you have it all figured out-it must either be a vibration motor under the front seat that is set to activate at 55 mph-or maybe you are imagining it, since every thing is alright...go figure...personally I hate it when I hallucinate...
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How could it be a tire or bearing if it happens when one or the other rear tire is lifted?
Dave
Can't be tire or bearing if it does it with either one or both rear wheels up.
Since the problem occurs regardless of which wheel is on or off the ground, the common denominator would be in the drive train. The question now becomes Trans or transfer case. I've changed all fluids and there are no contaminants in anything. This vibration feels exactly like a bent drive shaft or axle or u-joint angle issue, however I've owned the vehicle since it was a year old and never been in accident nor has the height been changed. It only has 100k miles and is used for vacations and trailer pulling. When I'm pulling a 35 foot trailer the vibration is less. It's been going on for 2 years.
Dave
If you read the initial-you would see it has a brand new shaft in it.That was the first thing I did.
Vibration is all over but not necessarily in the steering wheel. Its a tight humming vibration and it is very severe.
This vehicle is extremely well kept. The original aluminum wheels had corrosion from the wheel weights so I replaced them with exact same wheel. When the original set of tires wore out I replaced them with the exact same tire. When the wheels were replaced, they were balanced (couple months ago). This vibration has been there before tire and wheels and brakes where replaced. (roughly 2 years now).Vehicle is stored in the winter and is only driven regularly for a couple months in the summer.
I remember replacing one of the front wheel bearings but I have not tore apart any others for inspection.
When I spin up the rears I get no growling or noise. However I do seem to hear a slight growl when driving but its hard to tell with the humming of the bad vibration.
Its obvious I wasn't clear in my initial statement, Front drive shaft out its still there, rear drive shaft out still there, disengage engine above 55 its still there, torque or no torque its still there, one rear wheel up its there, other rear wheel up its there, both rear wheels up its there, new rear drive shaft, new front shaft joints, new transfer mount still there, put in auto 4wd still there 2wd still there 4wd high still there. There is no change in frequency or severity except for higher speed makes it louder and stronger but same frequency. New wheels and tires and rotors made no difference. I say its trans or transfer case but I cannot see what is in those two devices that could create this kind of tight vibration and so strong.
I've taken this vehicle on multiple long trips with this issue, with and without a trailer. I guess I'll wait till something breaks.
You obviously didn't read my statement. ITS A NEW DRIVE SHAFT. Problem was there before and after.
Since the torque converter spins at all times it cannot be that since I shut the engine off at 60mph and the vibration does not change at all.
yes and yes
Does anyone have any experience in drive line angle problems with 2000 Suburban?
If you had read my initial response you would have seen the problem exists with the front shaft OUT.
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