If I am correct I think I am missing 1 line to an externall oil cooler ( factory ? ) , I know the 2 lines go to the trans and right next to them on the drivers side they run over the axle and then cross under the oil pan and go straight up to a sideways mounted canister looking item under the exhaust manifold , I can see up into 1 fitting and I think I see cooling fins , anybody know what this is ? and is it hurting me to drive without , I have oil pressure and the guage is reading fine but dont know any temps. Thanks...by the way I have driven it about 2 weeks and it seems fine but would def. repair it if I knew what it is..

 

It sounds like you are describing the transmission cooler/heat exchanger. It keeps the trans fluid cooled to a temp about the same as the engine. The other function of this is to heat the trans fluid in cooler weather so it is up to proper operating temps in the cold weather. Now to your question... I personally don't think you should have any problem running with out it. Trans temp will be slow to rise in the winter, maybe not getting out of the 120-150 range. Mine has rusted out and leaking trans fluid. Gets removed this week! A bit of rerouting of the trans lines and it's done. If you don't think the trans cooling is going to be enough, add an after market cooler to increase cooling.