With quality transmission control module (TCM) tuning, the stock 68RFE can support 500rwhp and 1,000 lb-ft or more, but it won’t survive boosted, four-wheel drive launches for very long—and maybe not even once if the Low/Reverse sprag explodes (which is common). TCM Tuning Helps
Is the 68RFE a good engine?
Unfortunately, the 68RFE was hardly an improvement over the 48RE it replaced in terms of torque-holding capacity-and not even fortifying one means it will last (more on that below). But if you can manage to get the 68RFE to live while harnessing additional power, sooner or later the longer stroke of the 6.
Can a 68RFE Cummins live with a longer stroke?
But if you can manage to get the 68RFE to live while harnessing additional power, sooner or later the longer stroke of the 6.7L Cummins (and the added cylinder pressure that comes along with it) will bring you closer to your next performance roadblock: a blown head gasket.
How much power does a 408ci inline six make?
The 408 ci inline-six featured a bigger bore and longer stroke than its 5.9L predecessor had, and it packed 350 hp and 650 lb-ft of torque right off the assembly line.
How much line pressure can a stock 68RFE handle?
170 PSILine pressure is limited in a stock 68RFE to 170 PSI. Unfortunately, this is not high enough to reliably prevent clutch slippage above 400hp.
Are the 68RFE a good transmission?
The 68RFE is a well-designed and strong transmission with gear splits suited to the normal load-moving tasks faced by heavy-duty Ram diesel pickups. But it's not strong enough to handle the high-output Cummins if one is towing at or near the maximum rating of a Ram 3500 day in and day out.
Why does the 68RFE fail?
Because of their lack of mass, the 68RFE clutches have a very low tolerance to heat and do not dissipate it well. Once these clutches heat up past a certain temperature, they begin to distort. This decreases the overall clearance and causes the clutches not to release fully, eventually burning up (Figure 1).
Has the 68RFE been improved?
In 2019 Chrysler made several changes to the 68RFE. These changes included adding an auxiliary valve body, adding a dedicated TCC control solenoid, and changing the TCC regulator valve. Other changes include modifications to the valve body and the channel casting for controlled reverse and underdrive venting.
How much HP can a stock Cummins handle?
The 5.9L inline-six mill's factory rotating assembly from '89 to '02 is capable of handling 800 hp (1,400 to 1,600 lb-ft of torque) without breaking a sweat, and is often pushed into four-digit territory before aftermarket rods become a consideration.
How much horsepower can you get out of a 6.7 Cummins?
The Cummins 6.7L Turbo Diesel is the most powerful engine option for RAM 2500 and 3500 pickup trucks. Producing up to 400 horsepower and 1,000 pound-feet of clean diesel torque, this powerhouse helps RAM deliver best-in-class towing.
What is hot for a 68RFE?
So here is a fact you should remember: the ideal maximum transmission temperature is 200°F. For every 20 degrees you go above 200 you reduce the expected life span of the transmission by a factor of 2. Simply put, at 220 degrees you can expect ½ the life span, at 240 a ¼ and at 260 it is reduced to 1/8th.
Which is better 68RFE or Aisin?
Pros of the 68RFE: A final benefit to the 68RFE that may be relevant to some consumers is it's fast shift speed compared to the Aisin. This is because the 68RFE does not necessitate as much of a fuel de-rate during shifts to facilitate a safe and properly timed clutch to clutch transition.
How much horsepower can the Aisin transmission handle?
Aisin: The Aisin 6-speed automatic is one of the transmissions available with Ram's 6.7L Cummins turbo-diesel engine. This engine produces up to 400 hp and 1,000 lb-ft of clean-diesel torque. With the Aisin transmission, it can tow 31,000 pounds.
How can you tell the difference between a 68RFE and Aisin transmission?
All you have to do is open up the hood: If your yellow dipstick handle is on the right side of your engine (the driver's side), you're likely looking at a vehicle with an Aisin transmission. If your dipstick is just to the left of your engine, you're most likely dealing with the 68RFE.
How many gears does a 68RFE have?
The first improvement Chrysler wanted to make over the Torqueflite platform was, obviously, the amount of forward gear. For the 68RFE transmission, Chrysler opted to change to a six-speed unit. The additional gears allowed Chrysler to add higher 1st-gear ratios and tighter shift recovery from one gear to the next.
Is Ram getting the Allison?
Tons of upgrades are coming to the 2022 Ram 2500, but we hope one rumor becomes a reality. According to Pickup Truck News, the Ram 2500 could get a brand-new 10-speed Allison Automatic Transmission. Including a new Allison Transmission would provide the most notable upgrade for the model year.
When did the 68RFE come out?
On top of that, the 68RFE automatic transmission debuted in 2007.5 Dodge Rams, the first time a six-speed auto was offered in its ¾-ton and larger trucks.
What year did the 6.7 Cummins replace the 5.9?
As a direct result of tightening emission standards and consumer demand for more powerful engines, the 6.7L Cummins replaced the common-rail 5.9L midway through the 2007 model year. The 408 ci inline-six featured a bigger bore and longer stroke than its 5.9L predecessor had, and it packed 350 hp and 650 lb-ft of torque right off the assembly line. The 6.7L Cummins still made use of a Bosch common-rail injection system, but peak pressure increased from 23,200 psi to 26,000 psi and a variable geometry turbocharger (VGT) was employed for the first time. On top of that, the 68RFE automatic transmission debuted in 2007.5 Dodge Rams, the first time a six-speed auto was offered in its ¾-ton and larger trucks.