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The 68RFE is the six-speed automatic behind the 6.7L Cummins in Ram 2500/3500 trucks from 2007.5 up. It is a capable transmission, but the factory torque converter is its weakest link the moment you add a tuner or start towing near the truck's rating. The stock converter uses a single friction disc for the lockup clutch (TCC), and that disc simply cannot hold the torque of a tuned Cummins. It slips, glazes, overheats the fluid, and shudders. Once the TCC starts slipping, the whole transmission cooks itself.
If you tow heavy, tune the truck, or both, the converter is where you spend money first. Below is how to pick the right one instead of just buying the most expensive unit on the shelf.
Single-Disc vs Triple-Disc — What Holds Under Load
The whole game with a towing converter is TCC lockup clutch capacity. More friction discs equals more clamping surface equals more torque held without slip.
- Stock single-disc: fine for a bone-stock truck at moderate loads. Slips under a tune or heavy trailer. This is the part you are replacing.
- Billet single-disc: a billet cover and upgraded friction hold more than stock. Good for a lightly tuned truck that tows occasionally. The cheapest real upgrade.
- Billet triple-disc: three friction discs, roughly triple the lockup capacity. This is the standard answer for a tuned Cummins that tows heavy. It holds lockup at high torque without shudder and runs cooler because it is not slipping.
For a 68RFE that regularly tows near or above 15,000 lbs, or any truck with more than a mild tune, buy the triple-disc. The billet single is a compromise for lighter-duty use.
Stall Speed — Don't Over-Stall a Tow Rig
Stall speed is the RPM at which the converter starts efficiently transmitting torque. Diesels make big torque low in the RPM band, so you do not want a high-stall converter for towing. A high-stall unit that suits a drag truck will make a tow rig sluggish, run hotter, and hurt fuel economy.
| Converter Stall | Best For | 68RFE Towing Fit |
|---|---|---|
| Stock / low stall (~1,600 rpm) | Heavy towing, stock or mild tune | Ideal — keeps the Cummins in its torque |
| Mild raise (~1,800 rpm) | Towing plus some spirited driving | Good all-around towing pick |
| High stall (2,200+ rpm) | Sled pull / drag / big turbo | Avoid for daily towing |
For 90% of 68RFE tow trucks, a stock-to-mild stall billet triple-disc is exactly right. Only go high-stall if you are building a competition truck with a large single or compound turbos that needs help spooling.
The Converters Worth Comparing
Billet Triple-Disc (Sun Coast, DPC, Goerend class) — The Heavy-Tow Standard
Purpose-built 68RFE billet triple-disc converters from the diesel-transmission specialists are the go-to for a working Cummins. They pair a billet cover with a furnace-brazed impeller, upgraded stator, and triple lockup clutch. Expect to spend real money, but this is a buy-once part for a truck that earns its keep towing.
Check 68RFE billet triple-disc converters
Billet Single-Disc — The Lighter-Duty Upgrade
A billet single-disc holds far more than the stock disc at a lower cost than a triple. If your truck is close to stock, tows a lighter trailer, and you just want to stop the factory TCC shudder, this is the sensible middle ground.
Check 68RFE billet single-disc converters
Quality Stock-Replacement Converter — Bone-Stock Trucks
If your truck is genuinely stock, never tuned, and you just need to replace a failed factory converter, a quality reman stock-spec unit is fine and cheapest. But if you have any plans to tune or tow harder, spend the extra now — pulling the transmission twice costs far more than the converter did.
Check 68RFE replacement converters
What Else Has to Come With the Converter
Dropping a better converter into an otherwise stock 68RFE is only half the fix. The converter makes more clamping force; the rest of the transmission has to be able to feed and hold it.
- Valve body / TCC apply pressure: a billet converter wants firm, consistent lockup apply. A shift-kit or upgraded valve body work keeps the TCC applied hard instead of slipping.
- Fluid and cooling: ATF+4 in spec, and a proper auxiliary cooler. Heat is what killed the last converter.
- Fresh fluid and filter after install: any converter failure sheds friction material into the fluid. Flush the cooler lines and replace the filter or you contaminate the new unit.
- Correct flexplate bolts, torqued to spec: do not reuse stretched converter bolts on a tow rig.
Get all of it right the first time and the 68RFE behind a Cummins becomes a genuinely durable towing transmission.
68RFE Converter, Filter & Rebuild Parts — Ships Same-Day
When you swap the converter you want fresh ATF+4, a new filter, the right flexplate bolts, and often a shift-kit or solenoid pack while it is apart. gearboxinsider.com stocks 68RFE parts and ships same-day before 2pm Eastern with free shipping.
Shop Gearbox Insider →FAQ
How do I know my stock 68RFE converter is slipping?
Classic signs: a shudder at highway speed under light throttle (TCC slip), rising transmission temperature while towing at steady speed, and a tach that creeps up 100-200 rpm while road speed stays flat. Once you feel the shudder, the disc is glazing.
Can I install a 68RFE converter myself?
Only with the transmission out or a lot of clearance — the converter sits inside the bellhousing on the pump. Most people do it as part of a rebuild or transmission R&R. Prime the new converter with fluid before install so the pump is not run dry.
Will a billet converter hurt fuel economy?
A stock-to-mild stall unit that holds lockup instead of slipping usually improves towing economy, because a slipping stock TCC wastes energy as heat. A high-stall converter would hurt economy — which is why you do not use one for towing.