OK so im putting this tranny (rebuilt) back into my 01 T&C 3.8 and my mech told me their was antifreeze in my trans before he rebuilt it .. He told me to make sure that the collant lines were properly flushed prior to reinstalling the tranny. No I dunno what to do why the mix in the tranny... what needs to be fixed or replaced so that the trans fluid dosen't mix with coolant ...help don't want to ruin the new tranny!!!!

trans cooler is in the radiator.

So how is it mixing???

So how is it mixing???
radiator is bad, the trans cooler tank is rotted out and letting coolant into it!

Trans cooler would have to be leaking. Ck your coolant and see if the color has changed. If your trans had a lot of metal in it the cooler should also be checked for blockage and flushed. If not the debri will get into the trans and cause problems.Usually the trans fluid leaks into the cooling system because the cooler line pressure runs about 30 psi or more.

my 97 voyagers radiator cracked inside where the tranny line go into it and wasnt leaking and antifreeze went into the tranny and mixed so had to have my tranny rebuilt $2000 and a new radiator and instead of conecting the tranny lines to radiator i put a new tranny cooler. That was 5 years ago and havent had a problem since.

UPDATE..... sorry for the delay when I installed the rebuilt tranny my mechanic failed to inspect the trans cooler and lines so what happend???? My transmission lasted 2 hours before I went AGAIN!!!!!! after droping the tranny a second time he realized the trans cooler was clogged so the tranny was rebuit yet again but lucky for me it was not completly ruined so $140 dollars later my trans was put back together after buying a larger than oem afyermarket trans cooler my van is running much better.....