RAM5500 CAMPERTHING
OG Portal Member #183
weak-link said:the clunk is normal, nothing to worry about. the splines on the output shaft get worn and create slack(thud).
There used to be a fix for this called the McNamara Gear or something along though lines. Someone machines a new gear to fit over the worn splines and fix the clunk.
EDIT: Found a link, check this out:
http://forum.ih8mud.com/60-series-wagons/85248-mcnamara-gear-factory-gear-spacer-mod.html