Pop sound from front left when using 4a

[smurfslayer]

I’m not sure I agree with this diag. The noise in question only happens in 4a when turning left or right. Not sure how the transfer case would cause to happen.

A point of clarification:
Did you test in 4h ( non-pavement surface of course ) or 4L ?

 

[REX111]

A point of clarification:
Did you test in 4h ( non-pavement surface of course ) or 4L ?

The noise is question happens in 4a only. It does not happen in 2h.

 

[smurfslayer]

The noise is question happens in 4a only. It does not happen in 2h.

@REX111 - I’m not trying to be obtuse here, but asking did you test in 4h or 4l -- in other words, not a ‘road’ mode of the transfer case? The stealership is saying t/c.

You’re saying you tested in 2 of the 4 possibilities of the transfer case. I think it could make a difference but you wouldn’t want to be using 4h or 4l on pavement. hopefully that makes sense.

 

[CoronaRaptor]

@REX111 - I’m not trying to be obtuse here, but asking did you test in 4h or 4l -- in other words, not a ‘road’ mode of the transfer case? The stealership is saying t/c.

You’re saying you tested in 2 of the 4 possibilities of the transfer case. I think it could make a difference but you wouldn’t want to be using 4h or 4l on pavement. hopefully that makes sense.

 

[REX111]

I have not used 4l/4h on pavement. I only noticed this pop noise when using the 4a drive mode during small snow storm last year. The dealership has had my truck for most of January.

 

[K223]

This diag could make sense. 4A has power transferred to the front based on how much power is be produced by the engine and if the rear is losing traction etc. I’m sure there is a more technical strategy applied then I am trying to explain. But in 4A you are not running in locked out 4H/L and the transfer case applies power to the front by the clutches engaging within the transfer case. Meaning when in 4A it would be noticeable if there is a problem in the xfer case.

I can see what @smurfslayer is saying. If the truck doesn’t exhibit the same issue in 4H/L then it’s a better chance the problem is in the xfer case and could be the clutches within having a problem. The techs may have proved this switching and testing in diff drive modes. Either way the front torsen if equipped is always working but not having power applied to it in 2WD.

 

[smurfslayer]

That’s kind of where I was trying to go; by attempting to validate / invalidate in the other t/c selections, you may be able to rule it in or out.

Thanks for the assist @K223

So anyway, maybe the stealership is on to something, fingers x’d.

 

[REX111]

Dealership called this am and informed me that they will be ordering and installing a new transfer case. 3-4days out to get the part.

 

[CoronaRaptor]

Dealership called this am and informed me that they will be ordering and installing a new transfer case. 3-4days out to get the part.

That is awesome news.

 

[REX111]

Still waiting on parts..