Hey guys,

I'm new here and new to Diesels. Just bought the 07 Classic. I don't know if this was covered before but i checked the first couple pages and didn't see it. When i shift into the parking gear, it makes a pretty noticeable clacking sound. Is that normal? And if so, what causes it?

Thanks for your help.

Does it with mine.. More then likely the parking pawl falling into one of the sprag's notches..

Normal

Normal.

From the Allison website ~

PARK PAWL
The Allison transmission in the vehicle is equipped with a Park Pawl designed to hold 26,000 lbs. GCVW. To accommodate this safety feature, the transmission incorporates much larger parts than other automatic transmissions.
NOTE: An occasional “clunk” may be heard when the selector lever is moved from drive or reverse to park. This is normal and there is no damage occurring
during these shifts.

Don't put it into Park so fast. I noticed that if I go from Drive to Park in a normal manner, I get the clack. If I go from Drive, to neutral to reverse, pausing just a second in each detent, it does not clack. Try it for yourself and see if it works.

Normal noise..