i need to splice into either of the trans cooler lines' rubber portions...
the hard portions of the lines are crusty and i want to leave them.
i was wondering if anyone knows the ID of the rubber parts? i am guessing 3/8 but its just a guess

 

not sure on the ID
best bet is to replace the lines entirely. home made lines clamped with gear/hose clamps always leak. don't use dorman lines if you go this route.

 

Do you think the rubber portion on a same yr (07) impala with the same motor/trans combo would be the same? i see one of those in a local yard... my guess would be that it is the same... im hoping the rubber hose is nothing special and just a regular size. think i might cut one at the yard before i cut mine just to be sure im not waiting on special order ac delco replacement lines

unfortunately i have to get custom on it. an inline filter is overdue. i have previously used a snub of line that i flared and just plugged into the oem cooler but there isnt enough room over there to jam it all in that way. easiest way will probably be thru the rubber portion in the return line this go round.

last time i used worm gears without an issue but i agree that they are not ideal. the high quality USA built 'tridon' brand are much better than those marked china. i quit using non-usa ones a while back and had good luck ever since. home depot and parts stores here both carry tridons if i remember right, they say tridon usa on the body for sure.

i do have some pex clamps, they are basically just oetiker-style, i might give those a go but i believe this filter will be temporary so i will likely save those for the splice that stitches the rubber back to 'oem'

 

i clipped a piece of this hose off a junkyard impala with a 3.9L...
i promptly lost the piece i clipped of course. but i am fairly certain it was either 3/8 or 5/16 ID. however the notable thing about it is that the rubber seemed slightly thicker and harder than most transmission hoses i have handled. it is potentially not conducive to using any variety of clamp at all. it is probably better to cut and flare the metal line instead of trying to splice into this hose