Hi all, how do you tell if the rear end noise is typical chatter from a Traction Lok limited slip or is a sign that the clutches need to be replaced?

The rear end seems to be fine most of the time. When I'm turning and slowly driving uphill from a dead stop, I can hear some chatter from the rear end.

I've got 125,000 on the truck, so I figure changing out the fluid and the friction additive wouldn't be a bad idea regardless, but I'm looking for a quick test to see if the clutches are failing or if I'm just creating demons in my own mind.

2006, F150, 5.4L, RWD, axle code H9 (3.55 limited slip).

Thanks in advance!

 

Fresh 75w140 full synthetic and a bottle of Ford modifier sure wouldn't hurt - at 125k it's overdue.

 

My 2000 went 80k miles before the clutches started chattering on turns. A fluid change with friction modifier did the trick and no further issues up to 170k miles when my friend sold it and I lost track of it. My current 02 that I bought used at 69k miles has not chattered yet. I changed the fluid when I replaced an axle and axle bearing around 134k miles. Both have 9.75 rears with traction lock.

 

Thanks for the info! As I said, I was planning to do the fluid change anyway, so hopefully that will resolve the issue. I'll let y'all know if it doesn't.