lunk just after stating engine

[robbig]

Sometimes after just starting the engine, I get a single lunking sound and feel.
I have yet to take out of park so I can't imagine it's the dreaded slip yoke... Any opinions would be appreciated. 2005 2500 HD Duramax

Robbig

[DmaxMaverick]

Normal. The tranny is pressuring up and "lunks" against the parking pawl.

[robbig]

So many different noises on these trucks...

Robbig

[DmaxMaverick]

These "new" Diesels have all kinds of new noises. Really, the noises are the same old noises, it's just that you can hear them over the engine. In the old days:D, the engine was the noise.

[cowboywildbill]

If you listen for noises on a diesel too much, it will convince you something is wrong. Unless you hear a really bad & different louder type of noise, just do like they say on this forum "DRIVE IT LIKE YOU STOLE IT". ENJOY!

[REDTRUCK05]

It could be cabin pressure shutting the door on the intake for your heating system.

[mattb5150]

Good to know others have this. I passed on a neighbors 2004 Chevy with Dmax because it had this sound(among other things) and my 2002 Dmax/Alli didn't. Now my 2003 GMC has it but not as loud as the 04 Chevy that I was testing. Perhaps theirs was worse since they towed a giant fifth wheel toy box with 2 slideouts, it was a CC/SB SRW and they replaced it with an '06 dually?

[DmaxMaverick]

IF we are all talking about the same "noise", this is a non-issue. Some trannies do it, some don't, and there isn't a regularity to it. In any case, it's absolutely normal. Certainly NOT a reason to pass on an otherwise fine vehicle. The Allison tranny is much different, in both design and function, than autos used in pickups in the past.

[JohnC]

It could be cabin pressure shutting the door on the intake for your heating system.

Wow! I didn't realize these things had pressurized cabins! What's the critical altitude?
;)