48RE Overhaul Kit 2003, new and ready to install. Fits the 48RE. Ships fast from the USA.
2003 was the first year Ram put the 48RE behind the 5.9L Cummins in the 2500 and 3500, and most of those trucks are now on their first or second rebuild. If yours has a leak you cannot chase down from outside, slips when hot, engages late into Drive on a cold morning, or is simply coming apart for new clutches, this is the soft parts kit for the job. The photo shows a new kit sealed in Precision International packaging. An overhaul kit is the gaskets, seals and sealing rings; frictions, steels and the filter are bought separately.
Every clutch and band in the 48RE is applied by oil, and every circuit depends on rubber and Teflon seals to hold that oil where it belongs. The piston seals in the front, rear and overdrive clutches, the rings on the input and intermediate shafts, the pump and case gaskets, and the governor and pan gaskets all age at the same rate. Heat hardens them, and once a seal stops holding, the clutch it feeds slips even though the plates may be fine. The 48RE is less forgiving of this than the 46RE and 47RE before it: Sonnax notes that it raises line pressure only about 22 to 28 psi in fourth gear or with the converter locked, so a leaking circuit has little extra pressure to hide behind under Cummins torque.
The 2003 truck is also the early design. The throttle valve on the valve body is still moved by a cable, and Transmission Digest dates the switch to the electronic throttle valve actuator to 2005 on the diesel Rams. That matters when you order valve body parts alongside this kit.
Check fluid level the way Chrysler's service manual describes for the RE family: level ground, engine idling, selector in Neutral, and fluid fully hot. Low fluid alone causes many of the symptoms above. Then put a gauge on the line pressure port. Low pressure in every range points at the pump or pressure regulator, while low pressure in one range points at a leak in that circuit, which is exactly what new seals fix. Our 48RE pump failure guide covers the gauge tests, and the Ram 2500 Cummins 48RE problems guide lists the usual failures on these trucks.
This kit is listed for the 2003 48RE, which in that year means the Ram 2500 and 3500 with the 5.9L Cummins diesel. The RE family shares many seals across years, but gaskets and some rings changed over the 48RE's life, so compare the kit to the parts you remove during teardown before you throw anything away. The part number on the bag is not readable in our photo. If you need it to cross-reference, or want us to confirm fit, send your year and VIN before ordering. More 2003 to 2007 parts are in the 48RE collection.
| Fits | 48RE 2003 |
| Part type | Overhaul Kit |
| Condition | New |
| Brand | OEM |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. An overhaul kit is the gasket and seal set. Frictions, steels, the filter and any hard parts are separate. If your clutches are burned, replace them at the same time.
It is listed for 2003. Many RE seals carry across years, but some gaskets and rings changed, so send us your year and VIN and we will confirm before you order a kit for a later truck.
Not always. An extension housing or output seal can often be replaced in the truck. The full kit makes sense when the transmission is coming out for slipping, late engagement or a rebuild.
ATF+4 only. Chrysler's 2006 Ram capacity chart lists roughly 29 to 33 pints for an overhaul fill. Add most of it, start the engine, then top off with the fluid hot, selector in Neutral and the truck level.
Hardened piston seals and worn sealing rings leak more when the fluid is thick and cold, so the clutch takes longer to fill. New seals from a kit like this are the usual fix once fluid level and pump pressure check out.
