in-gear knocking on acceleration

i have an 84 mazda b2000. i was on the freeway in stop and go traffic when the knocking started. it only happens when in gear and accelerating. sounds like it's coming from the engine. does not knock when idling or when coasting in gear, only when in gear and accelerating. this happens in any gear including reverse. the knocking is fairly loud and sounds like i should not drive it until the problem is addressed.

please help.
thanks!
chris

are you sure its from the motor or the front anyways

Are you sure it's the engine? Mine does the same thing but it's coming from the trans. Hold the shifter while accelerating to see if you can feel it through there. If so it's probably your tranny too. Hope this helps you out.

thanks for the tip, i'll give it a check. if it is the tans, what do i do? change fluid? seals? new trany?