95saleen451

i am looking at a 99 cobra and was wondering if any one had any ideas as to what the clunking nosie is when i shift or if i just take my foot of the gas and put it back on it clunks like a rear arm or something is bad

torqjnky

The “clunk” is a moderate volume sound which typically occurs after depressing the accelerator following a coast. It is very noticeable in 5th or 6th gear depending on your tranny in most cases. This is caused by play in the driveline (fairly normal in Mustangs). Here is the official Ford directive about this issue.

Special Service Message 17510 (1999-2004 Mustang 4.6l - Driveline Clunk During Gear Changes And/or Quick Acceleration After Coast (tip-in Clunk)
Some 1999-2004 Mustangs equipped with a 4.6 Liter engine may exhibit a 'clunk' noise from the driveline during gear changes and/or a quick acceleration just after a coast (tip-in clunk). The clunk may be present in multiple gears and is considered normal. This is caused by driveline lash reacting to the rapid response of the engine when the throttle is suddenly opened. The clunk noise has no effect on the performance or durability of Tthe vehicle. Inspect and check the driveshaft attaching bolts, axle mounts, transmission mounts and sub-frame mounting bolts for proper torque. No other service should be performed.
Effective Date: 01/26/2004