horrible LOUD noise maybe tc maybe diff????

[cxs4887]

2001 yukon 5.3

so i have a LOUD LOUD noise ive heard diffs set up wrong and it sounds like the whine from a diff but it has a loud grind sound to it as well. it sounds more from the middle of the truck than the front or rear so i think its the tcase. the noise isnt bad when im just coasting not on the gas but when im on the gas its bad. ive spent hours looking through threads but coming short. so is it maybe a clip or chain in the tcase ? trans has fluid i will change the front and rear diff fluid this week and see. anyone have helpful tips?

also i havent driven fast in 4wd but the 4wd does work hi and lo when switching from drive to reverse it clanks. front cv axles are new. however it is on a 6 in suspension lift. and pushing 37s for a while but now on 40s

also the rear driveshaft has a small amount of play in it and the front shaft does not have any play.
the rear shaft looks like the seal is bad is has some oil sling around it maybe the tcase is just low on fluid from a leak?

 

[YukonXL04]

No clue, but how are you fitting 40's with a 6" lift? I would check the time case fluid first

 

[Donnie Yukonie]

Sounds like a Tcase , However My Tcase had a very expensive sound emitting from it when I selected any 4wd gear . Found out I had a stretched chain.

I had a whine , check the fluid

 

[ccapehartusarmyINF.(ret)]

humor me and check the drive shaft to see if it looks like its been rubbing on something
its probably a long shot but hey
i had a mysterious grinding noise on a different vehicle years ago
come to find out a crossmember bolts in the tranny either broke fell out or lord knows
anyways with out those bolts when you stepped on the gas the tranny shift a tad just enough so the drive shaft rubbed against the gas tank making a grinding sound
i spent all kinds of money replacing parts to try and fix it

ive seen or heard about drive shaft problems from suspension lifts but much higher then 6 inches

 

[cxs4887]

ill look tomorrow for the rub it also has a body lift it has a three inch body. the guy left the stock pucks in as well so i guess technically 4 inches of body. it scrubs though on the front.

 

[ccapehartusarmyINF.(ret)]

yeah it would make sense to check and see if your missing crossmember bolts or maybe u joints bad because from what your saying you step on the gas it gets worse wich would lead me to beleive motor and tranny is shifting slightly more then its supposed to when torque is applied causing like i said previously drive shaft to rub on something

 

[cxs4887]

heres the update guys, i looked under my truck today the rear driveshaft is stiff as a dead moose. no play at all. the front shaft does have some play in it. its not rubbing on anything at all. however there is some oil sling where some fluids leaking from the shaft seals havent got around to checking fluid. i took a video of the noise it makes it makes the noise in 2 wheel or 4 wheel even in park. ill upload the video to youtube and post the link on here asap.

---------- Post added at 08:47 PM ---------- Previous post was at 08:42 PM ----------

alright heres the link

https://www.youtube.com/watch?v=rk8TyH8XFt0&feature=youtu.be

 

[ccapehartusarmyINF.(ret)]

since it does it while idling in park start lookin in th motor you can rule out anything between the tranny and the wheels as being the culprit
is the constant clattering i hear in the video what your talking about?
if so does the clattering get faster when you rev the motor?

 

[cxs4887]

yes it does get faster it turns into a whine a loud whine at that.

 

[GangstaCowboy]

My 2006 Tahoe had a noise like this and it was the lifters going bad. Can you hear it from the engine bay close to the heads? I thought mine was TC at first as I thought for sure the sound came from under the truck.