02 Explorer auto 4wd rear end growl
 

My 2002 Explorer Eddie Bauer(69,000 mi) auto 4wd has a growl in the rear when turning slowly. My transmission shop thinks its the clutches in the posi-track rear. He changed the lubricant to make sure the proper type was being used. Still growling. He says Ford will only sell the clutch pack with the carrier ($800 plus $200 to install). I bet there is a better fix. Any suggestions welcomed. :confused:

When he changed the lube, did he put friction modifier in? takes 2 bottles. smells terrible, works great.

how much friction modifier
 

He (trans shop) added the friction modifier but I'm not sure how much. I'll check Monday before I start shopping for a used "open" rear axle with correct ratio. Thanks for the suggestion/information. Smells terrible, works great sounds like my son-in-law.
Regards