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2003 chevy
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Discussion Starter #1 (Edited)
Vibration in front end in 4WD

Whenever I put it in Auto, 4HI (didn't try 4Low) when I reach 25 MPH or so I get a vibration till about 30-35 MPH then goes away. I had the truck on the lift and you can see the right wheel movement at that speed. I put on MarkMC 2.5" lift and new CV shafts (A1 Cardone). I drove about 3500 miles on the new CV shafts before this started happening. I think its the CV shaft but before I go out and buy a new one I wanted to know if anyone had this happen to them before?
 

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When you say you see movement, what kind? The CV shaft is always spinning, driven by the wheel, even in 2WD mode. What changes when you engage A4WD or 4HI is the front axle actuator engages a splined disconnect and then the intermediate shaft that goes through the oil pan spins the same direction as the wheel and that changes the nature of the spinning inside the front diff.

How many miles do you have, and did you service the front diff or check its level? How about the transfer case? Its fluid change interval is a surprisingly short 50K.

The CV shaft is a certain suspect, but since it's always spinning I don't see it being the primary one.
 

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I had a vibration in my front end every time I was in the 40-48mph range. Didn't matter if it was 4Hi 4Low or normal 2 wheel it always vibrated. You would feel it through the steering column and pedals as time went on the vibration would get more noticeable. Ended up being the front wheel hub barrings. (I think that's what it was, I would have to dig up the repair invoice to be sure)
 

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It would be nice to have some more details. Vibration in the 35mph zone and 70mph zone can indicate a bearing.

You say you have vibration around 30mph - do you also have a vibration at 60mph? Generally a vibration due to wheel unbalance has repeated intervals of vibration intensity based on speed.

Have you checked tie rods and ball joints to ensure they are not loose? Those sorts of issues can allow the knuckle to oscillate at a certain vehicle speed given the right input forces.
 

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2002 chevy trailblazer_ltz
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I have a vibration in the steering wheel. It shows up at around 65 MPH. When I had my tires rotated and balanced, I was told that I had a blemish on the inside of a wheel. They moved the wheel from the front to the back and the vibration is still there. The vibration comes and goes as well. Any ideas?
 

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Again, more information is needed. It's impossible to diagnose when it's just called 'vibration'. Vibrations are hard to diagnose even in person.

What is the pitch - high or low? Does it happen in all gears? Does it change with left/right turns? Does it change with the speed of the wheels? or engine? Does 4WD have any affect on it? At what speeds does it show up?
 

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Discussion Starter #8
When you say you see movement, what kind? The CV shaft is always spinning, driven by the wheel, even in 2WD mode. What changes when you engage A4WD or 4HI is the front axle actuator engages a splined disconnect and then the intermediate shaft that goes through the oil pan spins the same direction as the wheel and that changes the nature of the spinning inside the front diff.

How many miles do you have, and did you service the front diff or check its level? How about the transfer case? Its fluid change interval is a surprisingly short 50K.

The CV shaft is a certain suspect, but since it's always spinning I don't see it being the primary one.
The movement in the wheel was like a wobble. Changed the CV shaft and still have the problem. It has 109K miles and fluids were replaced around 80K. I am going to check fluid levels and see if there is anything noticeable.
 

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Discussion Starter #9
It would be nice to have some more details. Vibration in the 35mph zone and 70mph zone can indicate a bearing.

You say you have vibration around 30mph - do you also have a vibration at 60mph? Generally a vibration due to wheel unbalance has repeated intervals of vibration intensity based on speed.

Have you checked tie rods and ball joints to ensure they are not loose? Those sorts of issues can allow the knuckle to oscillate at a certain vehicle speed given the right input forces.
The vibration is only happening at 25-35 mph. Tie rods and ball joints look good. I didn't notice if it happens when turning but it only happens when 4WD is engaged. If I am driving down the road with 4WD engaged and it starts shuddering/vibrating if I let off the gas pedal it stops and returns when I am back on the pedal till I get past 35-40 mph.

A mechanic friend thinks it might be low fluid levels Diff or TC or possibly in the transmission.
 

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Discussion Starter #11
I only use 4HI a few times here an there on paved roads when it snows heavy or pulling my boat in and out of the water. I use AWD more frequently when it rains or snows lightly. TC fluid was changed at 30K, and 80K now truck has 110K.
 

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Discussion Starter #13
I'm having trouble identifying it based on the information you've given me. Are you able to put the truck up on jack stands and engage 4WD and get the tires spinning? That may be the only way to track your vibration.
Yes, I have a friend who owns a shop and we have it on the lift right now. I've been out of town for a few days so I haven't had a chance to get over there and see whats going on.
 

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Discussion Starter #14
On the lift it looks like the CV shaft is bent, but that was just replaced with another new one. Not sure what the heck it is. Also had a replacement drive shaft put in to see if that was causing the problem. Nope!
 

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A bent cv shaft? Put a straight edge along the side of the shaft and see. Sometimes they have a little concentricity error with the CV joint ball - that could be what you're seeing - shouldn't cause a big problem especially since the weight is so close to the center of the rotation axis.

Try swapping your CV shafts - left to right, right to left - see if the vibration follows - that could confirm your suspicion.

Is the vibration only on one side?

What is the amplitude of the vibration? Big - as in the suspension is visibly vibrating? Or small - only a vibration that you can feel?

What is the frequency? Does it vibrate with wheel speed? If so, it's not the front prop shaft (they spin at different RPMs). Does it vibrate much faster than wheel speed? - it could be a bearing.

Describe what you're hearing and feeling? Is it a crunchy vibration? or a smooth oscillation?

You can see if the vibration is in your differential or in your wheels/hubs by removing your front CV shafts - putting it on the lift and running in 4WD. Or better yet, when on the lift, strap one wheel so it's held from rotating (the diff will cause the other tire to rotate at twice the speed)... see if the vibration is still there.

It's all a matter of logical deduction and a little ingenuity. Methodically rule each item out.
 

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Discussion Starter #16
First let me say Thanks for helping me in anyway you can. I will try and provide some answers but have had limited time lately and access to a lift to conduct some diagnosis.

A bent cv shaft? Put a straight edge along the side of the shaft and see. Sometimes they have a little concentricity error with the CV joint ball - that could be what you're seeing - shouldn't cause a big problem especially since the weight is so close to the center of the rotation axis.

Try swapping your CV shafts - left to right, right to left - see if the vibration follows - that could confirm your suspicion.

Is the vibration only on one side?
Both CV shafts were replaced with new different brands. Problem is still there.


What is the amplitude of the vibration? Big - as in the suspension is visibly vibrating? Or small - only a vibration that you can feel?

What is the frequency? Does it vibrate with wheel speed? If so, it's not the front prop shaft (they spin at different RPMs). Does it vibrate much faster than wheel speed? - it could be a bearing.
The vibration is present only when in AWD or 4WD. It only happens when accelerating at about 50% or higher throttle (if you accelerate slowly it doesn't happen). It does not happen with wheel speed, under acceleration around 25 MPH it will start to shake the steering wheel and vibrate the front end. It kind of feels like the motor is shaking but mechanic friend with lift said it was the right front wheel that was shaking. He also said that the movement seems to be that with each wheel rotation it is trying to get over a hump, almost like it binds at some point and has to get over it. I did not see this myself, he described it to me.


Describe what you're hearing and feeling? Is it a crunchy vibration? or a smooth oscillation?
The vibration is smooth not crunchy and is faster than wheel speed. The only thing that stumps us is that it only happens between 25-35 mph when 4WD is under load (being used). I drove in 2wd 75 mph with no problem. What bearing are you referring to? wheel? or a bearing in TC or Diff?

You can see if the vibration is in your differential or in your wheels/hubs by removing your front CV shafts - putting it on the lift and running in 4WD. Or better yet, when on the lift, strap one wheel so it's held from rotating (the diff will cause the other tire to rotate at twice the speed)... see if the vibration is still there.

It's all a matter of logical deduction and a little ingenuity. Methodically rule each item out.
Trying to get it on the lift again to try this out.
 

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No problem.

Both CV shafts were replaced with new different brands. Problem is still there.
Ok, so as you're saying, most likely it isn't the CV shaft directly. Did you by chance check the needle bearings that hold the inner CV when you replaced them?

The vibration is present only when in AWD or 4WD. It only happens when accelerating at about 50% or higher throttle (if you accelerate slowly it doesn't happen). It does not happen with wheel speed, under acceleration around 25 MPH it will start to shake the steering wheel and vibrate the front end. It kind of feels like the motor is shaking but mechanic friend with lift said it was the right front wheel that was shaking. He also said that the movement seems to be that with each wheel rotation it is trying to get over a hump, almost like it binds at some point and has to get over it. I did not see this myself, he described it to me.
Only when in A4WD or 4WD eh?... that tends to lead me to think it's a differential carrier or front prop shaft... but you also said it was the right front wheel.

So the more you're saying, it sounds like it could be the front disconnect that is causing your issue. Check the passenger side tripod housing... if it's really loose, that tends to point to the 4WD disconnect being the culprit.

Here's a writeup about rebuilding it: http://www.offroadtb.com/articles/tech-docs/front-axle-4wd-disconnect

The vibration is smooth not crunchy and is faster than wheel speed. The only thing that stumps us is that it only happens between 25-35 mph when 4WD is under load (being used). I drove in 2wd 75 mph with no problem. What bearing are you referring to? wheel? or a bearing in TC or Diff?
Generally if it's more crunchy, it could be the wheel bearing... generally a smooth vibration means an imbalance, but from what you said above, I'm not sure it's an imbalance.

Trying to get it on the lift again to try this out.
If you have 4 jackstands you can do it at home too (or with two jack stands, you can remove your rear drive shaft)... just make sure the ratchet strap is secure to whatever you're securing it to... you don't want it to be flung around the wheel well. This process will help you determine if it's driver's side or passenger side.
 

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sorry to pull open an old thread but im having pretty close to the same problem. Im wondering if the problem was solved for you northface_tb?

i have a 03 5.3L ext with 160k

I lifted my truck a month or so ago in doing so i rebuilt the entire front end; new cv's, wheel bearings, upper and lower ball joints, tie rod ends, sway bar end links, struts and added a liftmeister 3" lift and flipped the UCA's

when i engage the truck in 4wd, or awd at 25-35 it shakes in the right front, then goes away. i haven't taken it past 60 to know if it gets bad again at higher speeds.

One evening i noticed something strange though, and this may be part of the problem. When i reached in the right wheel well and grabbed the cv axle and shook it the inner spline was loose in the front differential. like there was play in it. is there a bearing in there that blows out and causes the inner spline to wobble around under load causing it to bind at certain points?

any help to point me in the right direction would be very helpful! thanks


-Dusty
 

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2005 gmc envoy_slt_xl
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Same here, same exact problem. Anyone find a solution yet? My mechanic thinks I should remove the front drive shaft and have it balanced-change bushings, rings, etc
 
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