Just bought a 2007 Yukon XL Denali

[petethepug]

Wow! No peeling of the clear coat on the roof or hood. Get some ceramic paint sealer on quick. Congrats on the new ride and the ride of the new ride with the MRC and bags. You should check to see when the trans, front/rear diff and xfer case. were last serviced. The slip could be something as simple as a trans service.

The typical low speed clunk when letting off the gas is usually the slip yoke. Grease it with the recommended goop and say good bye. Search for the thread on overfilling the motor with oil (at IDLE ONLY) and verify if you're low oil press is a bad o ring on the pick up tube starving the motor and of course remove said extra oil before driving again.

 

[brodown]

Thanks for all the info, will definitely look into the tranny, although my mechanic seems to think I shouldn't touch the tranny fluid at this stage.

I looked under the car and noticed it has an ac delco PF48E filter. While searching other forums I found this TSB: https://www.obd-codes.com/p0521

Now- my truck hasn't thrown this code, but I think I am going to change oil and put a different filter in (napa or K and n), and see if this changes anything. the TSB recommends ac delco UPF48R filter, but only if it is throwing P0521 code. Anybody ever run this filter?