Please help me to diagnose the driveline noise/vibration

[alp]

Hi guys,
The symptoms: Speed related humming/chattering/rumbling noise under acceleration from complete stop which then becomes low pitch but loud noise at higher speeds. It looks like it's coming from the rear side. After 30 mph and higher I also feel high frequency slight vibration in the floor.
My thinking is that either bad one of the propeller shaft u-joint or rear differential pinion bearings. Am I missing something else?
How to diagnose this noise?
I got under the truck and check the rear drive shaft u-joints. Everything look and feel solid but I am not sure if this is the correct method to check u-joints. Do I have to take the shaft off and check if u-joints have a play in the wise? How to do it?
If I take the rear drive (propeller) shaft off can I drive my 99 SR5 auto in 4X mode? I mean really drive the truck on the dry surface to work. I know it is not recommended when both drive shafts are engaged.
If this is rear differential bearings and I hope it is not will I hear that noise without rear drive shaft mounted?
Thanks a lot in advance.

 

[the great him]

it could be your carrier bearings as well or wheel bearings too...

 

[alp]

Thanks Kid,
So what would be the troubleshooting sequence?

I wonder if I would remove the rear drive shaft meaning that there will be no load on the rear differential pinion and drive the truck with front wheel drive will I would still hear the noise if the pinion bearings failed?

I am still not sure if I can safely drive the truck with disconnected rear drive shaft.

 

[the great him]

Thanks Kid,
So what would be the troubleshooting sequence?

I wonder if I would remove the rear drive shaft meaning that there will be no load on the rear differential pinion and drive the truck with front wheel drive will I would still hear the noise if the pinion bearings failed?

I am still not sure if I can safely drive the truck with disconnected rear drive shaft.

well dose the noise get louder if you go around a corner? like say when you make left hand corners is the noise noticeably louder or say right hand corners does the noise increase or change pitch ect?

i think you could disconnect and remove the drive shaft and drive the truck in 4wd, but im not sure if that will eliminate anything other than the U joint(s). as the rear axle turning would still spin the pinion gear.

i think if you do remove the drive shaft and drive the rig and the noise is still there, and it does not seam to be louder on left or right corners consistently then your options are either a pinion bearing or carrier bearings. either way if you are that far into replacing one of them just replace both the carrier bearings and the pinion bearing, that way you know both are good and dont have to spend the time and or money to have it torn all down again for a second time.

 

[alp]

well dose the noise get louder if you go around a corner? like say when you make left hand corners is the noise noticeably louder or say right hand corners does the noise increase or change pitch ect?

i think you could disconnect and remove the drive shaft and drive the truck in 4wd, but im not sure if that will eliminate anything other than the U joint(s). as the rear axle turning would still spin the pinion gear.

i think if you do remove the drive shaft and drive the rig and the noise is still there, and it does not seam to be louder on left or right corners consistently then your options are either a pinion bearing or carrier bearings. either way if you are that far into replacing one of them just replace both the carrier bearings and the pinion bearing, that way you know both are good and dont have to spend the time and or money to have it torn all down again for a second time.

Thanks Kid,

No turning left or right doesn't change the noise pitch. I will disconnect the rear drive and then will see what happen.
I would still like to know for sure if I can drive the rig in 4WD without rear drive shaft. Anyone can confirm that?

 

[alp]

Has anyone driven 99 SR5 auto in 4HI with rear drive shaft taken off so, basically, it is like front wheel drive arrangement?
Thanks.

 

[HCurphy]

All I have is a 2wd, but I don't see what bad could come from it...
I guess worse case maybe snap a cv? That's the weakest link right? I doubt that would happen, so I think it would be fine. Especially just for a few miles for diagnostic purposes.

 

[alp]

All I have is a 2wd, but I don't see what bad could come from it...
I guess worse case maybe snap a cv? That's the weakest link right? I doubt that would happen, so I think it would be fine. Especially just for a few miles for diagnostic purposes.

Thanks HCurphy,
My biggest concern is that the drive system was designed to be permanently rear wheel drive and when it’s needed the front wheel drive gets engaged. I am not sure if the front driveline is capable to handle 100% of torque when rear drive shaft is removed.

 

[jdjohn84]

A gearhead I work with was telling me just the other day that he did that with a Jeep one time when he broke the main drive shaft. He dropped the rear drive shaft, and then drove home (many miles) with just the front shafts using 4WD mode.

I have a 2WD that had the same symptoms, and it needed new u-joints. Just finished it last night and it totally fixed the problem.

 

[alp]

A gearhead I work with was telling me just the other day that he did that with a Jeep one time when he broke the main drive shaft. He dropped the rear drive shaft, and then drove home (many miles) with just the front shafts using 4WD mode.

I have a 2WD that had the same symptoms, and it needed new u-joints. Just finished it last night and it totally fixed the problem.

Thanks jdjohn84 for your input!
Did you replace u-joint(s) yourself? Any special tool is needed? Any practical advice? I wonder if it makes scence to replace all u-joints once the drive shaft is off?

 

[cordrayj1]

my rear pinion bearing sounded just like that before i had it replaced.have you checked your fluids in your diffs lately?

mine almost exploded. caught it just in time. im talking this thing was LOUDDDDDDDDDDDD at highway speeds!

but going slow <25mph, could really pin down the origin of the noise.

 

[jdjohn84]

Thanks jdjohn84 for your input!
Did you replace u-joint(s) yourself? Any special tool is needed? Any practical advice? I wonder if it makes scence to replace all u-joints once the drive shaft is off?

Here is a link to my posting, with suggestions at the very end.
http://www.toyota-4runner.org/3rd-gen-t4rs/105660-diagnosing-vibration.html

 

[brian2sun]

It's ok to remove the rear D/S and drive in FWD, but I wouldn't recommend doing it for a long period of time. And take it easy on the gas pedal especially around corners and pulling out of driveways while turning.

Before you do that though, make sure you check your u-joints the proper way. Put the truck in neutral (very important because the D/S needs to be free and under no stress) and block the tires. Get under there and push and pull on the D/S by the u-joints. It's normal for the shaft to have a little rotational play (that's just the space between the teeth of the gears), but if it has up/down or side-to-side play, the u-joints are toast.

Could be bad bearings, but given your symptoms, I'm leaning toward bad u-joints because they just don't last forever. How many miles do you have?

 

[alp]

It's ok to remove the rear D/S and drive in FWD, but I wouldn't recommend doing it for a long period of time. And take it easy on the gas pedal especially around corners and pulling out of driveways while turning.

Before you do that though, make sure you check your u-joints the proper way. Put the truck in neutral (very important because the D/S needs to be free and under no stress) and block the tires. Get under there and push and pull on the D/S by the u-joints. It's normal for the shaft to have a little rotational play (that's just the space between the teeth of the gears), but if it has up/down or side-to-side play, the u-joints are toast.

Could be bad bearings, but given your symptoms, I'm leaning toward bad u-joints because they just don't last forever. How many miles do you have?

Thanks Brian.
I've got your advice on checking u-joints and easy driving with removed rear drive shaft.
The truck has only 125K but the previous owner has never greased u-joints.
I did it last summer but it looks like it was too late.

 

[alp]

Here is a link to my posting, with suggestions at the very end.
http://www.toyota-4runner.org/3rd-gen-t4rs/105660-diagnosing-vibration.html

Thanks jdjohn84!
Very helpful info and I am not sure how did I miss your recent post :naughty:
I have 4WD so the rear drive has a double cardan joint. It looks like if it's gone I have to replace the complete assy.

Forgot to ask if you reused old snap rings or bought the new ones?

 

[alp]

Update:
Last weekend I took the rear drive shaft off and took the truck for a ride with 4HI on so it practically was a front wheel drive. No noise from the rear!
Today I have replaced the rear drive shaft u-joint (the rear one) put the shaft back and took the truck for a test drive. Noise is back!
That humming noise that gets slowly converted into a growling sound proportionally to speed.
Does it look like I have a bad rear differential?
What else I can do to find/verify the source of noise?
Thanks!