Bowler Transmission Front & Rear Cooler Fitting (-6AN Male 9/16-18 NPSM Thread)

GM 4L80 transmissions came from the factory with one short (front) and one long (rear) cooler adapter. The longer rear fitting is required on the 4L80E for proper cooling and lubrication of the transmission. Check the thread size on your transmission before ordering. Note

• Some 1997 & later transmissions use 1/4-18 NPSM threads
• Some 2009 & later transmissions use 9/16-18 NPSM threads

Simplify your transmission cooler installation by using Bowler transmission cooler line fittings. These line fittings are manufactured from aluminum, and meet or exceed OEM standards for quality. Please Read These fittings fit most 2009+ & GM Performance crate transmission cases with 9/16-18 threads. The other option is 1/4 NPST thread, which is the most common from 1996-2008. The best way to know is to remove the stock adapters and measure the diameter of the threads. If you measure 0.5568", they are 9/16-18 and this is the correct option. If they measure 0.521", these will not fit and you will need the 1/4 NSPT option, which is the most popular.