Name this noise

[haligen]

Well I got permission from the wife to make the rally our big family trip this summer but whether it will be with truck or not depends on a few things. The last thing I want to do is get a tow from PA to SC. My biggest concern is this noise I have emanating from the transmission tunnel (or at least that is where I think its coming from). The truck seems to shift and run just fine (E4OD). It shifts around 3400 rpm if you bury your foot or around 2000ish if your just putting around. The shifts are pretty firm but not to bad. I ran down the road yesterday and recorded the noise maybe someone has a better clue then I. BTW I have done the passenger side wheel bearings. Haven't made it to the drivers side yet. I want to tell myself its a worn out bearing noise but really have no clue.

http://www.firehousetech.net/noise.mp3

 

[Jake_IN]

Maybe the U-joint at the front of the drive shaft? Just a SWAG sense the noise is delayed from the engine which tells me what ever is making the noise isn't directly connected to the engine.

 

[Dieselcrawler]

i would check ujoints and the carrier bearing. since it doesnt go away when motor rpm is dropped, it isnt in motor or trans.

 

[icanfixall]

I agree with the above postings. Its not the engine or trans. I feel its a universal joint. Probably the front joint but have all of them and the carrier done at the same time... then balance the shaft.

 

[haligen]

Well just went and got two new u-joints and a carrier bearing assembly. Hopefully the rain will quit and I can get them swapped out.

 

[icanfixall]

Hate to say this but your going to need more than two u joints to replace all of them....

 

[haligen]

Well I had some kid free time tonight so I decided to tackle the ujoints and carrier bearing. What I thought would be relatively pain free has turned into murphy slapping me stupid. The rear section came out just fine but when I went to remove the carrier support bolts they both decided not to budge. Then my impact decided that if they didnt want to move it would just round off the bolts. A little cutting and some cussing later everything was apart. Managed to get all the ujoints out without much fuss but then I went to put the new ones in it was another story. For the life of me I couldnt get the damn cross hatch into the ears on the shaft. 20 minutes later I realize autozone gave me the wrong ujoints. Off to the parts store. Right ujoint in their computer wrong one for my shafts. Back the year up on the computer and we get the right joint. Back to the house. Now I start reading on this carrier bearing and how to get it off. Hydraulic press and some bearing plates off it comes. Now how to get it back together? A piece of pipe and a hammer gets it back together but the outter part of the bearing is a little dented in. Now on to the ujoints. Get em all back in then realize I mixed up the carrier and transmission ends on the two shafts. Throw tools back into the garage and call it a night.

 

[benton]

when mine shifts and starts to lug out it kinda sounds like a old well broken in 4speed lol but it works fine

 

[haligen]

Finally got the shafts back in with three new u-joints and a carrier bearing. Noise still there.

 

[benton]

lol i blew up my tranny today so if i was you i would take it to a tranny shop for diagnosis!!!!

 

[ManicMike]

Check and see if a brake backing plate is touching the rotor. It's speed-related, not trans. Jack up the front end and spin each wheel as fast as you can, see if the noise show's up.

 

[Dsl_Dog_Treat]

Check and see if a brake backing plate is touching the rotor. It's speed-related, not trans. Jack up the front end and spin each wheel as fast as you can, see if the noise show's up.

Judging by the noise I gotta agree. Kind of sounds like one of the backing plates has gotten bent into the rotor or rusting out and fatigued and is making contact with the rotor.
Wouldnt hurt to check the rear brakes as well. That way you've got those pre rally checks out of the way.

 

[Shadetreemechanic]

It sounds like something you can diagnose by setting the truck on jackstands and spinning the wheels. I have a bearing going bad in the rear end of one of my trucks that sounds like that at speed, but is more of a creak at very slow speeds.

 

[haligen]

Well when I did the wheel bearings I checked the brake backing plates and re-greased the new u-joints. Still have the noise, it sounds like it is coming straight up from the transmission tunnel. Could a speedometer cable maybe make that noise? Mine bounces like its sticking. Guess thursday I throw it on jack stands and crawl under.