Drivetrain noise. Can't solve the mystery.
#1
08-23-2011, 10:29 AM
Howling noise. Driving me insane.
Need help with this one. Have spent a ton of money and not getting anywhere.
My 2000 Blazer LS (2wd) makes a howling/ whirring sound when in gear (sounds just like bad wheel bearing). Can feel vibration in foot pedals...not much, but enough to be irritating. slight shimmy in steering wheel, but I think that's a tire balance issue.
- 104k miles. Engine and tranny all original
- no performance loss and MPG on 500 mile drive last weekend was about 22mpg.
- does not burn oil
- have replaced all wheel bearings
- new tires and are all at correct pressure
- both front rotors and pads are less than 5 months old and rear pads are the same age ( first thing I replaced trying to resolve the issue)
- replaced transmission filter/fluid (there was hardly any residue in the pan).
- replace plugs and wires. The old plugs were still in good shape.
makes the sound in 1, 2 3 and drive. Does not make the sound in neutral. swerving makes the sound go away when in gear. There is no slipping and gear changes are smooth as silk.
I just replaced both front hub assemblies this past weekend the rears were replaced 2 months ago.
Does not appear to be a U-joint, but I'm not a mechanic.
Any advice would be appreciated. She still has a lot of life left in her and just want the noise to go away.
My 2000 Blazer LS (2wd) makes a howling/ whirring sound when in gear (sounds just like bad wheel bearing). Can feel vibration in foot pedals...not much, but enough to be irritating. slight shimmy in steering wheel, but I think that's a tire balance issue.
- 104k miles. Engine and tranny all original
- no performance loss and MPG on 500 mile drive last weekend was about 22mpg.
- does not burn oil
- have replaced all wheel bearings
- new tires and are all at correct pressure
- both front rotors and pads are less than 5 months old and rear pads are the same age ( first thing I replaced trying to resolve the issue)
- replaced transmission filter/fluid (there was hardly any residue in the pan).
- replace plugs and wires. The old plugs were still in good shape.
makes the sound in 1, 2 3 and drive. Does not make the sound in neutral. swerving makes the sound go away when in gear. There is no slipping and gear changes are smooth as silk.
I just replaced both front hub assemblies this past weekend the rears were replaced 2 months ago.
Does not appear to be a U-joint, but I'm not a mechanic.
Any advice would be appreciated. She still has a lot of life left in her and just want the noise to go away.
#2
08-23-2011, 10:43 AM
'swerve' hint tells me...
Wheel alignment
Bad bearings - still
Bad Tires - still
Sorry, You're going to have to find someone, up close and personal, who KNOWS cars.
Pretty sure you'll get an answer in about five minutes that would take DAYS of back and forth on here. I mean, really.. you cant even point out the general direction of the noise.
Wheel alignment
Bad bearings - still
Bad Tires - still
Sorry, You're going to have to find someone, up close and personal, who KNOWS cars.
Pretty sure you'll get an answer in about five minutes that would take DAYS of back and forth on here. I mean, really.. you cant even point out the general direction of the noise.
#3
08-23-2011, 10:52 AM
I am most likely going to have to bite the bullet and take it in to get checked out. I've resisted only because this is my only vehicle and I can't be with out it. I've done everything I thought would take care of this and I HATE being defeated, but it is what it is.
#4
08-31-2011, 10:16 AM
Drivetrain noise. Can't solve the mystery.
I posted a message a few weeks back and did not get many responses. trying again with new observations so see if anyone can help. I live in a small town and I have two choices for "professional" help. One knows what he is doing, but has such a backlog that I would not see my vehicle for a month (my only mode of transport) and the other knows that I am not from here and will suck every dollar out of me they can. I need your help!
Problem. Humming/grinding starting at around 15- 20mph and turning into a whining sound at higher speeds. Sound turns to a grinding at deceleration at low speed (5mph to stop)
2000 Blazer LS 2wd
105k
New rotors and pads (march 2011)
New rear bearings (june 2011.... replaced by money sucking repair shop that wanted 400 a pop to replace the front hubs)
New front hub assemblies (august 2011)
New tires...not matched front and back, but at correct pressure.
Tranny filter and fluid changed two weeks ago and barely any residue in pan...no metal.
Shifts smooth (no slips...very responsive)
Engine is strong and gets regular maint....no coolant loss.
No sound when in neutral rolling down a hill.
Sound only happens when I'm on the accelerator or when coming to a stop (sounds like bad rotors, but my rotors are clean and not scared).
My bearings were bad and replacing them cut the noise down, bit I'm at a loss on tracking down the source of the rest
Gas gauge quit working early last year...have not seen any performance loss (fuel pump)
I'm trying to put out as much info as I can. I love this truck and just want to keep her rolling as long as possible....if you need more info please ask....I'll do my best to answer.
Problem. Humming/grinding starting at around 15- 20mph and turning into a whining sound at higher speeds. Sound turns to a grinding at deceleration at low speed (5mph to stop)
2000 Blazer LS 2wd
105k
New rotors and pads (march 2011)
New rear bearings (june 2011.... replaced by money sucking repair shop that wanted 400 a pop to replace the front hubs)
New front hub assemblies (august 2011)
New tires...not matched front and back, but at correct pressure.
Tranny filter and fluid changed two weeks ago and barely any residue in pan...no metal.
Shifts smooth (no slips...very responsive)
Engine is strong and gets regular maint....no coolant loss.
No sound when in neutral rolling down a hill.
Sound only happens when I'm on the accelerator or when coming to a stop (sounds like bad rotors, but my rotors are clean and not scared).
My bearings were bad and replacing them cut the noise down, bit I'm at a loss on tracking down the source of the rest
Gas gauge quit working early last year...have not seen any performance loss (fuel pump)
I'm trying to put out as much info as I can. I love this truck and just want to keep her rolling as long as possible....if you need more info please ask....I'll do my best to answer.
#5
08-31-2011, 10:52 AM
*Combining Threads* - Please keep all of the information on this topic in one thread. It is permissible to 'bump' the post with new information.
By a few weeks, you mean just last week...
There seems to be some conflicting information... But seeing as how you have replaced a ton of stuff without curing the problem, lets dive into what you haven't changed and may not have checked. The accel/decel note from your recent explanation of the conditions/symptoms seems to point further up the driveline. Have you inspected the u-joints in the driveshaft? How about the pinion for play? Have you pulled the rear diff cover & inspected the pinion & ring gear teeth or differential bearings? I would have thought that a shop replacing the rear outer wheel bearings would have done a thorough inspection of the differential since they have to be in there to remove the axles...
By a few weeks, you mean just last week...
There seems to be some conflicting information... But seeing as how you have replaced a ton of stuff without curing the problem, lets dive into what you haven't changed and may not have checked. The accel/decel note from your recent explanation of the conditions/symptoms seems to point further up the driveline. Have you inspected the u-joints in the driveshaft? How about the pinion for play? Have you pulled the rear diff cover & inspected the pinion & ring gear teeth or differential bearings? I would have thought that a shop replacing the rear outer wheel bearings would have done a thorough inspection of the differential since they have to be in there to remove the axles...
#6
08-31-2011, 10:54 AM
I posted a message a few weeks back and did not get many responses. trying again with new observations so see if anyone can help. ..
Problem. Humming/grinding starting at around 15- 20mph and turning into a whining sound at higher speeds. Sound turns to a grinding at deceleration at low speed (5mph to stop)
...
No sound when in neutral rolling down a hill.
Sound only happens when I'm on the accelerator or when coming to a stop (sounds like bad rotors, but my rotors are clean and not scared).
...
I'm trying to put out as much info as I can. I love this truck and just want to keep her rolling as long as possible....if you need more info please ask....I'll do my best to answer.
Problem. Humming/grinding starting at around 15- 20mph and turning into a whining sound at higher speeds. Sound turns to a grinding at deceleration at low speed (5mph to stop)
...
No sound when in neutral rolling down a hill.
Sound only happens when I'm on the accelerator or when coming to a stop (sounds like bad rotors, but my rotors are clean and not scared).
...
I'm trying to put out as much info as I can. I love this truck and just want to keep her rolling as long as possible....if you need more info please ask....I'll do my best to answer.
'swerve' hint tells me...
Wheel alignment
Bad bearings - still
Bad Tires - still
Sorry, You're going to have to find someone, up close and personal, who KNOWS cars.
Pretty sure you'll get an answer in about five minutes that would take DAYS of back and forth on here. I mean, really.. you cant even point out the general direction of the noise.
Wheel alignment
Bad bearings - still
Bad Tires - still
Sorry, You're going to have to find someone, up close and personal, who KNOWS cars.
Pretty sure you'll get an answer in about five minutes that would take DAYS of back and forth on here. I mean, really.. you cant even point out the general direction of the noise.
Suggest more testing in neutral rolling.. .. sound from 50 to stop. Change when brakes applied?
What Kyle says above is key and points to suspicion of differential.
I'll say again.. one guy with car experience will probably solve this in less than ten minutes and shops are not the only place to find them.. another hint.. he is probably older than twenty yo
just saying.
Find a local car club and seek out geezer enthusiasts who actually wrenched on their own cars.
A chevy street rod club.. or a ford bronco club.. hell even a VW club maybe..doesnt matter. These guys will help you.
Last edited by pettyfog; 08-31-2011 at 10:57 AM.
#8
08-31-2011, 06:21 PM
Not a chevy specific problem but here's my input. At my job we have a lincoln Fwd that's making the same noise.....or WAS making the same noise under the same conditions, it then progressed into a trans slip, and all kinds of other fun stuff. (that is if it's the same noise i'm picturing) it could be an internal trans problem.
HOWEVER, check the easy stuff first, u joints, slip yokes, driveshaft balance (not easily checked unless you work for a driveline shop), obvious wear on parts, Transfer case fluid, rear end fluid, front diff fluid, etc.
HOWEVER, check the easy stuff first, u joints, slip yokes, driveshaft balance (not easily checked unless you work for a driveline shop), obvious wear on parts, Transfer case fluid, rear end fluid, front diff fluid, etc.
#9
09-01-2011, 07:53 AM
thank you everyone for your help.
When inspecting u-joints, what should I be looking for? Does the vehicle need to be in neutral? Whats the best way to do this?
Also, this might sound like a dumb question, but is there anything I need to know about removing the rear diff cover? Will something come spilling out....anything I can add like gear lube? Dumb, I know, but I have never removed that cover on any vehicle I have owned.
Again, Thank you for your help.
I'll post updates when I get a chance to look at it.
scratch that rear diff question....found some information on it.
When inspecting u-joints, what should I be looking for? Does the vehicle need to be in neutral? Whats the best way to do this?
Also, this might sound like a dumb question, but is there anything I need to know about removing the rear diff cover? Will something come spilling out....anything I can add like gear lube? Dumb, I know, but I have never removed that cover on any vehicle I have owned.
Again, Thank you for your help.
I'll post updates when I get a chance to look at it.
scratch that rear diff question....found some information on it.
Last edited by swartlkk; 09-01-2011 at 08:01 AM. Reason: *Combining Consecutive Posts* - Please use the edit function to add additional information in your post if another member has yet to respond.
#10
09-01-2011, 08:14 AM
Rear Axle Service should give you an idea of what's involved when pulling the cover.
As far as the u-joints, I like to pull the driveshaft to check them. Gives you a much better feel. There are 4 bolts back at the yoke on the rear axle and then it will just pull out of the transmission tail housing (you may lose a bit of trans fluid when it comes out - nothing to worry about). You are feeling for grittiness, abnormal stiffness, and/or play in each of the cups (4 per u-joint).
As far as the u-joints, I like to pull the driveshaft to check them. Gives you a much better feel. There are 4 bolts back at the yoke on the rear axle and then it will just pull out of the transmission tail housing (you may lose a bit of trans fluid when it comes out - nothing to worry about). You are feeling for grittiness, abnormal stiffness, and/or play in each of the cups (4 per u-joint).