Source Of Clunking With Auto Transmission

[mentalward]

My '66 coupe with transplanted 302 w/auto trans has occasional clunking issues. I shifted from low to D1 (once) at a low speed and it clunked pretty hard (decided not to do that again). It occasionally clunks hard when shifting from Neutral to Rev. It sometimes clunks when shifting from N to D1, but not frequently. It's definitely touchy.

I initially assumed the clunking was related to the transmission itself, but had no idea if it was normal for a car this old, or even if it was normal back in the day. I read something yesterday that now makes me think it might be the differential. Any thoughts? Take it to a tranny guy?

Thanks.

 

[horse sence]

Universal joints will clank if they are worn ,so will the rear end if the gears or bearings are worn . A broken transmission mount or motor mount will also cause a clunk when shifting in to gears .A high idle will cause a clank if parts are worn also .