growling differrential

hi, im looking to buy this 94 2500 cargovan. it has 300kms on 318/3spd
when i test drove it, there is a growling sound in the differential. the dealer said that is common on dodge ramvans. even my buddy told me the same.

i was going to buy it yesterday until i saw a water leak underneath after i test drove it. dealer said they will fix it before they will give it to me.
the water is coming from the front engine, dripping from the crankshaft pulley/balancer. dunno if its the pump or just a hose, but it was leaking like a faucet.

so is that growling sound normal on this vans?

thanks

so is that growling sound normal on this vans?

Absolutely NOT! That differential is going to need a rebuild job very soon.