I have a 2004 ram 1500 with hemi and auto trans. Truck has 429,000 miles stock engine (never been apart) 410 gears with TruTrac.

At 45 MPH the truck cuts out aggressively... (like the Throttle is being pushed in and out ) (hard to even hold on the steering wheel) for about 10 seconds ,,,,,making it almost impossible to go over that speed. when it finally does,,,the truck runs fine until Its turned of and restarted. then I have to go through the problem all over again.
(it does not do it when the truck is cold in the morning, only warm truck)
No Trouble codes that could be related.
Fuel pressure at 60 psi and steady
Idles fine and has no misses.very quiet. Compression 185 -190 psi all 8 cylinders. Cleaned all ground throughout vehicle.
transmission is rebuilt 1 year ago. Engine does not burn oil.
Head Gasket test good. No air leaks intake.

I have replaced just about everything that could be related.. the list of parts replaced..( Some are extra parts I had,, but did not have issues with)
REPLACED
1. Torque converter and trans oil pump (TTC limit valve is in the pump)
2. throttle body
3. BCM body control module
4. TPMS (fuse

box) replaced also replaced relays and fuses.
5. PCM (reman)(computer) programmed vin and miles. (tried 3 different units)
6. All sensors on engine block 6 total, knocks, ect and all speed sensor- 4 total
7. MAP sensor and EGR valve
8. Ignition module and clock spring
9. Spark plugs/wires and coils
10. Front wiring harness under hood and into dash
11. Instrument cluster - programmed tried 3 different ones
12. Fuel pump inside tank (fuel filter is in pump)
13. Cat's are 1 year old
14. Tried a different alternator
15. Transmission pressure sensor
16. APPS Acc Pedal Position Sensor. TBPS
17. Tried a second valve body after rebuilding
18. Solenoid pack (white one)
19. Trans filters (both)
20. All 4 oxygen sensor. (NGK)
21. PVC valve
did hard resets.. quick learn on trans. tied battery cables together over night..
throttle learn, crank sensor reset all that stuff..
Inside trans looks good pulled out the input drum (while pump was out) inspected no debris in oil.

 

What's your voltage look like when it's acting up

 

14 volts stable. I tried a 190 amp alternator this weekend with no luck. I am thinking its the transmission at this point..

 

Hard to tell without being in the driver seat whether or not it's a mechanical cutout in the trans, or something engine related.

When it cuts out, do the RPM's drop? If so, and with everything else being sprayed with the shotgun, and at nearly 430k on the clock, I'd look at injectors. I don't know if 04 has live misfire data but give it a looksee, at least maybe see if the misfire monitor is ready.

If RPM is stable or jumps up when it cuts out, I'd look at the transmission again (engine RPM would spike when the load was pulled of during a slip event in the transmission)

 

ended up being the TTC valve in the transmission oil pump.. I got the reamer kit $399..and put in an oversized Valve by Sonnex.. fixed it . thanks for your help...
Dodge Transmissions are a pain to rebuild. at least the RFE's are,,, but its nice knowing I can do them myself now. If you do one, make sure everything is perfect and clearances are correct overdrive, underdive and lower reverse... and input and output shaft too. .get a sonnex re-manufactured valve bode and a good oil pump with updated valves. Or don't waist your time. cheap is not the way to go..
they don't forgive..