F100 Transfer case
we have a problem with an F100 transfer box which sounds as if it is jumping out of gear, with big banging noises and we can see the drive shafts 'springing' as the box slips.
this happens in 4wd low range, and we can make it happen by just selecting 4wd low and holding the brake and applying power.
the truck is an auto.
any help would be appreciated.