Is this normal? - Driveshaft Slip Yoke

[oplersx]

I crawled underneath to investigate the vibrate sound that happens when accelerating on uphill. Like the sound of a piece of metal vibrate or a bolt loose at joint, hard to describe. Say, I am in 5th gear cruising then hit an uphill, as soon as I step on the gas lightly just to maintain the speed, there comes the sound. If I hit the gas harder, gear drops to 4th or 3rd, that sound will almost disappears...

I found nothing loose, just noticed this area (red circled), is this normal?

 

[Deleted member 12951]

Yep

 

[oplersx]

Yep

OK... I thought that was the problem

Any ideas?

 

[t_j]

That is normal. That is the slip 'yoke' on the drive shaft, the shaft has to grow and shrink as the rear suspension cycles, to achieve this the shaft is allowed to slide in and out of the output port on the transfer case.

Your noise maybe in your transfer case, mine is doing something similar at the moment, and I can't engage 4wd (tcase does not shift). I will be taking it to the dealership soonish to get it sorted.

 

[oplersx]

That is normal. That is the slip 'yoke' on the drive shaft, the shaft has to grow and shrink as the rear suspension cycles, to achieve this the shaft is allowed to slide in and out of the output port on the transfer case.

I see!

Your noise maybe in your transfer case, mine is doing something similar at the moment, and I can't engage 4wd (tcase does not shift). I will be taking it to the dealership soonish to get it sorted.

Does the noise always there? Or like mine, only happens going uphill? Absolute nothing on level road/downhill in my case.

 

[oplersx]

UPDATE:

Nothing wrong mechanically... It's the tune caused engine ping. Restored to stock, noise gone...

Now has to determine why? I have been running the tune for about a year, only noticed the noise month ago.

 

[Deleted member 12951]

What tune and what octane gas you using? Filled up lately at a station that you normally do not go?

 

[oplersx]

What tune and what octane gas you using? Filled up lately at a station that you normally do not go?

SVC tune... always Shell 91 (I am in Canada), and always one of the two Shell stations close to my house.

As far as I can recall, I noticed the noise 1~2 months ago, never thought it's the tune, as I have been running the tune for over a year! Restored to stock, drove 20kms back home, no noise...

 

[Deleted member 12951]

SVC tune... always Shell 91 (I am in Canada), and always one of the two Shell stations close to my house.

As far as I can recall, I noticed the noise 1~2 months ago, never thought it's the tune, as I have been running the tune for over a year! Restored to stock, drove 20kms back home, no noise...

Well I know that by default the SVC tune is set for 91. If you run 89, you need to adjust the spark advance down 2 and if 87 down 4. Wonder if that station messed up and not dispensing the right octane or old gas. You can try re-tuning with a -4 on it and see if that resolves it. Or better yet get hold of Jeff or Jarrett and see what they say. @svc

 

[oplersx]

Gas is 91. Not my daily drive so usually one tank per month, I doubt the gas is the cause. But why it happens now not from the beginning bugs me... Already email Jeff, see what he says.

The tech booked the truck in to have it checked. So I will run stock tune until checked over. Just back from another test drive, so far so good on stock tune.

Well I know that by default the SVC tune is set for 91. If you run 89, you need to adjust the spark advance down 2 and if 87 down 4. Wonder if that station messed up and not dispensing the right octane or old gas. You can try re-tuning with a -4 on it and see if that resolves it. Or better yet get hold of Jeff or Jarrett and see what they say. @svc