Billet bypass valve that replaces the leak-prone factory thermal bypass on 2013-2018 Ram 2500/3500 6.7L Cummins with the 68RFE or AS69RC.
Owners of 2013-2018 Ram 2500 and 3500 trucks with the 6.7L Cummins usually find this part after one of two things: transmission temps that climb on every long grade, or ATF weeping from the joint where the cooler lines meet the transmission. Both trace back to the factory thermal bypass assembly. This CNC-machined billet aluminum valve bolts into the same spot, takes the wax thermal element out of the circuit and sends fluid through the cooler full time, behind either the 68RFE or the Aisin AS69RC.
On these trucks the cooler lines do not run straight from the transmission to the cooler. They pass through a bypass assembly with a wax element that keeps cold fluid circulating inside the case until it warms up, then opens to send it to the cooler. Two things go wrong with age. The element sticks, so the valve stays partly in bypass and the cooler sees only a fraction of the flow it should. And the joint at the cooler line connection starts to seep. A billet body with no element fixes both: there is nothing left to stick, and the machined aluminum housing replaces the factory one.
GEARS Magazine puts the ideal maximum transmission temperature at 200 F and says expected life is cut in half for every 20 F above that, so a stuck bypass on a towing truck is expensive. Before buying, rule out the other causes the same article lists: kinked or crushed cooler lines, a plugged cooler, a plugged filter, a trailer over the rated capacity, an engine running hot and a fan clutch out of spec. A flow test at the return line should show at least a gallon per minute. Our guide to common 68RFE problems on the Ram 2500 covers the heat-related failures, and if you are deciding between keeping the 68RFE or swapping, the 48RE vs 68RFE comparison shows where each unit is weak.
This valve fits 2013-2018 Ram 2500 and 3500 trucks with the 6.7L Cummins diesel and a 68RFE or Aisin AS69RC. It does not fit 2019-and-newer Rams, which use a different bypass design, and it is not for the 2007-2012 trucks. Match the shape and mounting of your current valve to the photos, or send your year and VIN and we will check it. For everything else that fits this transmission, see the 68RFE shop page.
Clamp the cooler lines or have a catch pan ready, then unbolt the factory bypass assembly. Transfer or replace the line fittings and O-rings, and lubricate the new seals with ATF+4 so they do not roll as the valve seats. Bolt the billet valve into the factory location and reconnect the lines; there is no cutting, drilling or programming. Because the cooler circuit now fills immediately, the dipstick will read low after the first start. Top off, drive until the fluid is at least 160 F per the FCA procedure, and set the final level hot. If the truck has a history of overheating, a deep cast aluminum 68RFE pan adds fluid capacity, and the ATSG 68RFE rebuild manual is worth having if the heat has already done internal damage.
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Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. It fits 2013-2018 only. 2019-and-newer trucks use a different bypass and need the later-style valve.
Yes. On 2013-2018 Ram 2500 and 3500 6.7L Cummins trucks it fits both the 68RFE and the AS69RC.
The cooler and lines now fill as soon as the engine runs instead of waiting for the old valve to open. Top off with ATF+4 and set the final level with the fluid at 160 F or warmer.
If the leak is coming from the factory bypass housing or its seals, yes, because the whole assembly is replaced. A leak at the line itself or the cooler needs to be fixed separately.
No. It installs with hand tools. Have a drain pan ready and fresh ATF+4 for the top-off.
