Like the title says, and I am about to go nuts over here. I have an 02 suburban 4X4 , just turned 90,000 miles. About a week ago, I hear a noise from under the truck, kinda sounds like its located under the console area.
The noise is kind of a *tink tink tink* metallic sound. Reminds me of a piece of wire wrapped around the driveshaft and the loose end is hitting as the shaft turns. Only makes the noise in first, under light throttle ad usually stops (or at least I cant hear it anymore) at aroud 2000 rpms when it shifts to second.
I cannot replicate the noise at idle, only when driving. Wont do it when I brake torque it to try and replicate it. Once upon a time I remember another post about the PWM valve could be locking and unlocking causing the noise?
It isnt an exhaust rattle issue, it does it whether I am going straight or turning, theres nothing on or around the driveshafts. For some reason I am wondering if its a torque convertor issue...any insight would help, thanks guys. Ron

 

U-joint in front or rear d-shaft is my guess.

 

Could it make that type of noise? I am planning on replacing them because I get a slight clunk when putting it in gear.....I hope thats the cause of this noise, but I am skeptical. Any more ideas guys? Thanks, Ron

 

put it on jack stands and put it in gear and get someone under their i bet it is a planetary

 

As in planetary gear......as in the tranny taking a ****??? God I hope not. It has auto trac, I suppose i should try to get all 4 in the air so I dont kill anyone.
I'll try that tomorrow. I should add that the sound is somewhat intermittent....might not hear it for a day or two, might hear it everyday. It ALWAYS makes the noise when going up the parking garage ramp at light throttle, guess it has something to do with the load on the trans.
Only does it while giving throttle, if I let off the gas, it stops immediatly. Keep the ideas coming guys, there might be a prize for the right answer. Ron

 

Ok, jacked it up today and tried to replicate the problem...no luck. Didnt even do it when I drove it so today must have been a good day for whatever is wrong with it. Would a planetary problem be intermittant like this? Gimme some ideas here guys, I already mentioned the winning guess gets a prize! Thanks, Ron

 

i am no expert on automatics, but i'm pretty sure that planetary problems won't just come and go. one went out on my dad's dodge and it took a dump fast. i think once they are messed up, they only get worse. one thing though, you could check your flywheel to tc bolts. sounds dumb, but it's free and easy to check. i've seen them back out enough to hit stuff and make tinking noises!

 

Redwagon, I'll check the bolts. I am no auto trans expert either, I wish I was. It sounds kinda silly, but it's raining here and I dont want to get the car out in the rain just to pull the Suburban in on the lift. I still need to change the u-joints out to see if thats an issue also. Something is definitly going on, the sound almost reminds me of something metallic that is binding. I am still open to more suggestions, thanks Ron.