4Runner drive-train vibration and squeak... Is it a U-joint?

[Erich_870]

Vehicle: 99 4Runner, 3.4L automatic
Miles: 130,000

Symptom: Last Friday an annoying "tweety bird" squeak started up with a noticeable vibration at highway speeds. I had a co-worker drive slowly around the parking lot as I homed in on the sounds point of origin. Nearest I can tell, the sound coming from right behind the transfer case (rear drive shaft).

Is this a bad U joint? And if so, how to I go about fixing it?

Thanks guys :thumbup:

Erich

[Erich_870]

Help me out here guys! It sounds like I'm being chased by a pack of rabid squirrels! :hillbill:

Seriously, I need my rig for work and I'm hesitant to drive it very far. :wrenchin:

Erich

[YotaFun]

When the u-joints were going in my friends 4Runner, he didn't have a noise, but boy did he have a bad vibe, it was like driving a truck that had a massage chair built into it.

Sounds more like a bearing is starting to go.

Can you get under the truck and see if there is any play?
However according to ShopKey (proggy from school) a noise could be associated with a u-joint going out.

[CJM]

Bearing sounds more like it.

However could be bad u-joints, but usually there is a very noticeable CLUNK into every gear (very noticeable from P to D/R) and possibly at take off or if you hit the gas hard when driving at speed.

If its a hum its a bearing, if its a drivetrain vibe you will feel it at all speeds usually.

Does it squeal only when moving?

[Erich_870]

Thanks both of you guys with good points and questions :thumbup:



Bearing sounds more like it.

However could be bad u-joints, but usually there is a very noticeable CLUNK into every gear (very noticeable from P to D/R) and possibly at take off or if you hit the gas hard when driving at speed.

If its a hum its a bearing, if its a drive train vibe you will feel it at all speeds usually.

Does it squeal only when moving?


Which bearing are you thinking of?

It's not a hum, it's literally a squeak that is directly related to the speed of the drive shaft. At below 5mph its about once a second and gets faster up to highway speed. It also vibrates at highway speed.

The other thing is that the sound goes away with my foot of the gas. It's quite when I coast.

Erich

[YotaFun]

After this comment I am more likly to believe it is a u-joint:


The other thing is that the sound goes away with my foot of the gas. It's quite when I coast.

Erich


The reason I say this is because one if it was a bearing, the sound would be constant when moving and two, when I let off he gas or in coast on my friends 4Runner the vibrations would go away, so it is definetly sounding more and more like a u-joint.

[Erich_870]

The reason I say this is because one if it was a bearing, the sound would be constant when moving and two, when I let off he gas or in coast on my friends 4Runner the vibrations would go away, so it is definetly sounding more and more like a u-joint.


awesome, we're on to something here. So what do I do to fix a u-joint? :wrenchin:

Erich

[reggie 00]

The reason I say this is because one if it was a bearing, the sound would be constant when moving and two, when I let off he gas or in coast on my friends 4Runner the vibrations would go away, so it is definetly sounding more and more like a u-joint.


awesome, we're on to something here. So what do I do to fix a u-joint? :wrenchin:

Erich


Grab some V paste and.......






JK

Get a new one and replace it.

Have a vise some grease and some small/big sockets on hand. Its not to hard.
The last ones i did were really in there had to beat the living expletive out of them to get them out.

[Erich_870]

Grab some V paste and.......






JK

Get a new one and replace it.

Have a vise some grease and some small/big sockets on hand. Its not to hard.
The last ones i did were really in there had to beat the living expletive out of them to get them out.


I was reading about replacing u-joints in my Haynes manual and it said that if the failing one is in the double cardan joint than I have to buy a whole new (or refurbished) drive shaft. :chair: How do I locate the failed U-joint? Do I do it when it's still on the rig or on the bench?

Thanks guys :thumbup:

Erich

[reggie 00]

on the bench

a ujoint is basically a cross with some needle bearings on the ends.

the bad one will be really sloppy as the needle bearing will have failed.

when you take the drive shaft out flex the joints to check for excess play.

I'm not sure on the double cardan joint, i have never had to mess with one.

[Erich_870]

on the bench

a ujoint is basically a cross with some needle bearings on the ends.

the bad one will be really sloppy as the needle bearing will have failed.

when you take the drive shaft out flex the joints to check for excess play.

I'm not sure on the double cardan joint, i have never had to mess with one.




Sounds good. Fingers crossed it's not the double cardan joint... :roll:

I just found some random pictures I took of my rig from below and the double cardan is right where I heard the squeaks from, so this could be expensive :(

I'll have to wait until this weekend, when hopefully it's a little dryer and take it off to test it. I'll just drive it until the new one gets here if it is the problem :hillbill:

Erich

[reggie 00]

na

looks like you might be able to rebuild it.

http://www.rblewis.net/personal/bronco/driveshaft/

good stuff here

http://www.pirate4x4.com/tech/billavista/PR-shaft/

and here

http://www.4crawler.com/4x4/CheapTricks/Driveline-101.shtml#FixingProblems

pictures

http://www.pavementsucks.com/tech/doublecardan.php

didn't have time to read all the pages, got to get the kids to school.

Hope it helps.

[CJM]

A bearing isnt always constant, ive seen plenty have the hum come and go.

[Erich_870]

A bearing isn't always constant, I've seen plenty have the hum come and go.


No hum here, squirrels from hell... :hillbill:

Erich

[Erich_870]

Found a local guy on Craigslist parting out a 99 4Runner, 4x4 4 cyl with manual transmission. With the assumption the transfer cases are the same, the rear drive shaft should be a direct swap, right? :wrenchin:

Erich

[CJM]

Why dont you change the u-joints first and see?

[Erich_870]

I bought the used drive shaft yesterday. Took it off the rig climbed under mine and it had the same part number, so that's cool.

I decided to by the second drive shaft because I'm 95% sure it was coming from the cardan joint. I've read thru all of Reggie's links and Toyota cardan joints don't appear to be rebuild able (which is in line with what the Haynes manual says). I could be wrong, but I figured I'd just get a second shaft to be safe.

Is there anything I should do to over haul this new shaft, other than adding fresh grease to all the zirks?

Erich

[Erich_870]

So I swapped out drive shafts on Wed and have my silent sanity back :clap: Then I promptly used my renewed trust in my drive train to mangle my lower skid plate on a job site :hillbill: Note to self, keep at least one wheel track on the high berm crated by D9 Cat Dozers and Volvo Off Road Trucks :shake:

I'm going to rebuild my original shaft and keep it as a spare.

Erich