Most do! Dropped my trans temps even when driving in the steep mountain grades. Easy install and not a bad idea to do to avoid problems in the future. Wish I would have done this years ago. Installed it during a trans fluid and filter change.

Definitely works, my bypass tube was Rusty and this is the cheaper alternative to keeping the tranny cooler, without breaking bank.

After working through rounded flare nut on trans cooler line (thanks previous owner), the kit installed very quickly. A JW valve body, a little bigger pan, DP Tuner tunes, and trans fluid flush and finished off deleting cooler bypass. Haven't driven enough to compare trans fluid temps.

Tranny was running 200 to 240 all the time, loaded or unloaded, put kit on and towed from Wyoming to Utah with small trailer, temp never went above 140

Great product... time for preventative maintenance on my 4R100. Having already purchased a MAG-HYTEC deep trans pan, JW custom Valve Body, new case MERCON and filter.... this was the final piece, for now.
Very satisfied with this item!

Fit perfectly and the new washers sealed nicely