Loud Noises Coming From Transfer Case

[JAMIEZ71]

Hey Guys,

I've got 03 gmc sierra with a 4L60e - 246 - m30 transfer case. It suddenly started making horrible noise in all gears but 3rd. The tone changes as the gears change. Transmission acts as if it shifts fine and not slipping. With truck on rack when wheels turn the noise is definately coming from the last couple inches of the transmission and the 1st several inches of the transfer case. The noise sounds like a grinding noise. Anyone have any clues? It's going to be Monday before it can be checked out at the earliest. No metal flakes in tranny fluid but transfer case looks like it has some stuff in the oil. Any help with this guys?

 

Thanks,

 

UPDATE:

Just drained transfer case fluid and it's black as West Virginia Coal. I had just changed it about 5-8000 miles ago with the correct bright blue fluid from GM. Sounds like it has let go.

[JAMIEZ71]

update 2

changed the fluid again just to see what it did and it made the noises worse. Is there a clutch pack or something that would cause this? Sounds like new transfer case would be the best bet because mine has also suffered from the little wear holes from the dogs on the shaft in the case.

[JAMIEZ71]

Is anyone on today at all? I figured I'd have some opinions by now.

[hockeypro1411]

If the noise is coming from all gear but 3rd, it's probably not a transfer case issue. The transfer case is always in motion, even in 2wd. It has to be something in the transmission. (I think)

[JAMIEZ71]

If the noise is coming from all gear but 3rd, it's probably not a transfer case issue. The transfer case is always in motion, even in 2wd. It has to be something in the transmission. (I think)

 

Put a new transfer case in because old one had a couple pin holes in it and the oil was full of metalic after only about 5000 miles. Put it back together and it seemed all the noise was gone for a bit.

 

Drove it this morning and boom the overdrive went out or started grabbing, then 1st and 2nd gear started whinning. No reverse now and won't go into park. Transmission is shot and for no reason.

[music]

If the noise is coming from all gear but 3rd, it's probably not a transfer case issue. The transfer case is always in motion, even in 2wd. It has to be something in the transmission. (I think)

 

Put a new transfer case in because old one had a couple pin holes in it and the oil was full of metalic after only about 5000 miles. Put it back together and it seemed all the noise was gone for a bit.

 

Drove it this morning and boom the overdrive went out or started grabbing, then 1st and 2nd gear started whinning. No reverse now and won't go into park. Transmission is shot and for no reason.

 

 

There's definitely a reason, there always is. Unless you have access to cheap, used parts, the problem you described would be best evaluated by removing both the transmission and the transfer case and inspecting. One failed before the other, causing the other to go shortly thereafter. Either way, both have to be evaluated at the same time when a hard part fails at the output end of the transmission.

[JAMIEZ71]

I ordered a new tranny yesterday. The planitary gears is what tore up in the transmission. At least now I'll have a whole new drivetrain other than the engine. Hopefully I don't have any problems there. 5.3s seem to be good for many miles.

[JAMIEZ71]

got my new transmission installed today. I had a level 3 stage 2 shift built at mad dog transmissions. Dynoed for up to 700hp. Now when I run across a few grand extra it will be time for a supercharger or something to put the new drivetrain to use.

[2005LT]

Sounds like a plan to me As bad as it is to have a transmission go out on you, it gave the opportunity for an upgrade.

[JAMIEZ71]

Sounds like a plan to me As bad as it is to have a transmission go out on you, it gave the opportunity for an upgrade.

 

Yeah I hated that it happened but it should be bullet proof now. I put my 93 oct tune back in today. I'll be working on dialing it back in to this tranny and I'm thinking about some long tube headers to go with it all.