Allison tranny cooler line size?

[Squaremaxfan]

I want to verify tranny cooler line size and I'm also wanting to install a dealer cooler in line w/electric fan mounted to it. The cooler is 3/8 line, will that work for the Allison cooler lines?

Thank in advance

 

[Ron Nielson]

I'm pretty sure that the lines are larger than that, probably -10an (5/8"). I believe that someone posed a similar questin to Mike L about that a couple of years ago and he said that 3/8 wouldn't be enough flow and cautioned against restricting trans fluid flow in the cooling circuit..

 

[2004LB7]

I think it was 1/2" for the 5 speed and 5/8" on the 6 speed. and as Ron mentioned, restrictions are not good

 

[Mike L.]

They are 5/8

 

[Squaremaxfan]

Ok, thank you guys for the info

 

[THEFERMANATOR]

All the lines are 5/8"/-10. 01-early 03 had fittings that necked down to 1/2", but they still used 5/8" cooler lines.