Thats what I thought...Iwouldnt mind them voiding the warranty if they made the change for me.Heartbeat that was my 2000 truck...My 2004 has a 100k extended warranty and only 28k miles on it.Does anybody have a rear end that wines or sings when its cold.Mine does it every morning as I coast down to the stop sighn.And only for a short time...Probly cold lube