69Boss302

Guys, I need a little help figuring this one out. 02 Silverado 4L60E 2wd 176,000miles



Last night the truck developed a squeaking noise. It sounds like something spinning and is based on speed. It stops when in neutral and still coasting and does not show itself in reverse. There is a burning smell, rubber or plastic, but can't determine if it's from the squeak or from leftover plastic bag stuck to the cat and still burning off.

I've ruled out the engine (does not happen in park or change with rpm's) and the driveshaft, U-joints (take the trans out of gear and it stops. The drive-shaft would still be turning because it's connected to the rearend and the noise stops when out of gear.) Nothing is leaking, all fluid levels are fine and nothing that I can feel is getting hot.


Any ideas what it could be? I can't get good audio because of windnoise.

Thanks

69Boss302

I've decided to replace the U-joints starting with the rear one first.

Didn't go so well tonight though. Burned out the plastic retainers and it still won't come out. It's too late tonight to break out the sawzall or hammer (I live in apartments and have a garage so it echoes badly) but tomorrow morning everyone will be at work.

viciousknid

iTrader: (8)

I haven't changed U-Joints on these newer trucks. but I've never had to associate the word plastic with the word U-Joints. You lost me on that one, what retainer are you speaking of?
I've never heard of u-joints squeaking either, they usually pop.
Does it do it at certain speeds or is it continuous at all speeds from the time you start to roll?

I messed up the pump to my 700r4 in the blazer and it would squeak real loud but it would mainly do it at startup and reverse sitting still.

Surprised someone hasn't chimed in what a resolution yet. Keep us updated.

FryZ71

Every U-joint I've had go bad has squeaked...it bet it's the u-joint on yours, too. It won't squeak when in nuetral or while coasting because there is no load on the rear end...it will do it when under power. W/ 176K on the original, it's time. I melted the plastic out of mine and still had to use a hammer for persuasion, just be careful not to damage the ears on the shaft.

69Boss302

Got the new u-joint in this morning. Had to use a cut off wheel to get the old u-joint out. That thing is so damned hard it would instantly dull the metal sawzall blades.

Went for a test drive and so far, no returning symptoms.

69Boss302

I got an opinion yesterday from my mechanic (aka dad) and he told me the exact same thing.

I had wanted to replace them a long time ago but never did. The only other time I've had u-joints go bad, they just exploded. I'm sure they squeaked too, just never heard them doing it. I don't listen to the radio much anymore so now I get to hear more things.

Thanks for the advice.

viciousknid

iTrader: (8)

So the plastic you mentioned is the plastic sack INSIDE the u-joint right? I didn't realize they got hot enough to melt out.

Glad it was something so simple to fix.

69Boss302

it needs to be heated to about 500f to burn it out. It pops out just like popcorn too. It brought a smile to my face at least watching it.

stocker

the newer n3r serires u-joints use plastic type material to hold the caps in instead of snap rings. if you heat up the tube youke it will start pissing out the hole they inject into like a curly sting, but be careful sometimes they will shoot out for some reason. once that out of the way set the other caps on top of a opened up vise(like 2 3/4 since u-joint is about 3 5/8) the cap will not fall out its got a .007 to .010 press fit so the needle bearing will spin not the cap. if it fall out you need another tube yoke welded on. then hit downwards on the tube yoke ear(under the cap above the weld) with a descent size ballpin the trunun will pushout the cap. then reverse. good luck

69Boss302

well, the noise is now back as of yesterday and it seems a bit worse. It is now present during acceleration and coasting to a stop. Does not change pitch while braking. I can hear it inside the cab now, almost like it's directly underneath the backseat. And the burning plastic smell is still there and all of the plastic bag has burned away from the catalytic converter now.

The only other thing I can think of at the moment is to change the front and middle U-joints and carrier bearing.