zf4hp22 auto tranmission pipe diameter

[BigKriss]

Hi guys, anyone know the internal diameter of the transmission lines. I want to run an external transmission cooler in the car. I am thinking of cutting off the line near were they enter the radiator and putting on come tube adapter fittings and then running some lines to a trans cooler that I have.

Here is what the tube adapter fittings look like but I dont know what size of fitting to get to go onto the transmission line There is a video here how to install them

[BigKriss]

Hi Jeff. Yes I got some measurements from Rustam on here. I think they are around 3/8" ID. I will try and get a size on the end of the line from where the nut is but I will bypass the stock cooler in the radiator. I dont think the transmission temperature can get too cold.

[BigKriss]

Yes. It never gets that cold here and I have a temperature sensor to put on the pan too.

[BigKriss]

For reference here is what it looks like. There is a large thread talking about the cooler here, but its not for e34s.

[Rustam]

Where is the rest of this thread???

[BigKriss]

thread went bye bye

[632 Regal]

Wasn't pertinent.

[Rustam]

the internal diameter of the transmission lines

Found the fitting going onto the radiator of 535 at transmission line. The internal diameter at the end is just under 8 millimeters. The outer diameter is about 10 millimeters. The diameters at the main extent of the pipe are larger - internal about 9.5 millimeters, external about 12 millimeters. Please note that this pipe, despite having the internal at the end of 8 millimeters, does not perform the same as a pipe that has 8 millimeters internal diameter through out. A pipe having entire length of 8 mm internal diameter is more flow restrictive.

[BigKriss]

Thanks for that. Look like 3/8" ID pipe size is what I need.