68rfe Slipping after take off

[Tbd]

I'm having issues with my 68rfe slipping in lower gears but it's still smooth in the higher gears. Most of the reading I've done on here seems to suggest that the higher gears would typically go out first if the transmission was needing a rebuild. I don't know if the transmission was ever rebuilt. I just bought it and I'm the second owner, the truck is at 300k I knew of the slip before I bought.

I'm taking it to a shop next week but based on what I read in this forum I'm interested if anybody here has any input on the circumstances of this specific case?

 

[transe]

Do you know what fault codes are set? Does it put you into "1st and 4th gears only" mode?

 

[SFTwinTurbo]

68rfe

Do you know what fault codes are set? Does it put you into "1st and 4th gears only" mode?

Hello I have a 2015 3500 6.7 w/ 68RFE, it has a twin turbo setup, anarchy tune, and a stock trans w/ 15k miles. The trans started slipping after fourth and would eventually not let me exceed 25 mph, i would step on the pedal but it wouldn't gain speed. Trans was limiting the gear selector to gears 1-4. It prompted a few trouble codes of Aux 4 output to high and another sensor output to high but i didn't write them done by accident.

 

[transe]

Hello I have a 2015 3500 6.7 w/ 68RFE, it has a twin turbo setup, anarchy tune, and a stock trans w/ 15k miles. The trans started slipping after fourth and would eventually not let me exceed 25 mph, i would step on the pedal but it wouldn't gain speed. Trans was limiting the gear selector to gears 1-4. It prompted a few trouble codes of Aux 4 output to high and another sensor output to high but i didn't write them done by accident.

Sounds like you should be getting a Gear Ratio Error fault. The fault descriptions you noted don't necessarily correspond to transmission faults. See if you can get the actual codes.

 

[SFTwinTurbo]

Sounds like you should be getting a Gear Ratio Error fault. The fault descriptions you noted don't necessarily correspond to transmission faults. See if you can get the actual codes.

The following codes were prompted:

P1475
P090E
P0414
C2009

Thank you in advanced.

 

[transe]

The following codes were prompted:

P1475
P090E
P0414
C2009

Thank you in advanced.

P1475 = Intake Air Diverter Valve Out of Calibration/Missing Calibration
P0414 = Secondary Air Injection System Switching Valve "A" Circuit Shorted
P090E: No such fault code exists in our records
C2009: No such fault code exists in our records

None of these are transmission faults.

 

[SFTwinTurbo]

P1475 = Intake Air Diverter Valve Out of Calibration/Missing Calibration
P0414 = Secondary Air Injection System Switching Valve "A" Circuit Shorted
P090E: No such fault code exists in our records
C2009: No such fault code exists in our records

None of these are transmission faults.

Thx sir!!

Sounds like the intake is the problem lol. Well I here's what happened, I reloaded the tune and took the truck out and it only prompted those codes, but the truck wouldn't get out of get out of fourth. So I shut off the truck and turn it back on and, viola, the truck will not move in any gear lol. I think it's the transmission:{

Now is it the transmission or the clutch pack, in other words if I change the clutch pack would the transmission operate normally?

 

[transe]

Thx sir!!

Sounds like the intake is the problem lol. Well I here's what happened, I reloaded the tune and took the truck out and it only prompted those codes, but the truck wouldn't get out of get out of fourth. So I shut off the truck and turn it back on and, viola, the truck will not move in any gear lol. I think it's the transmission:{

Now is it the transmission or the clutch pack, in other words if I change the clutch pack would the transmission operate normally?

When you say, "will not move in any gear," I presume that includes Reverse? What do you get in Drive / Reverse? Does the engine just free rev (like it's in Neutral), or does it feel like the trans engages normally, but the brakes are stuck on, so the truck wants to move but can't? What do you get in Neutral? Does the truck want to move at all?

Is it a 4x4? If so, have you tried it in 4WD mode? Does the trans fluid smell burned and/or is it black? If you check the fluid level (idling in Park), does it read higher than normal?

 

[SFTwinTurbo]

When you say, "will not move in any gear," I presume that includes Reverse? What do you get in Drive / Reverse? Does the engine just free rev (like it's in Neutral), or does it feel like the trans engages normally, but the brakes are stuck on, so the truck wants to move but can't? What do you get in Neutral? Does the truck want to move at all?

Is it a 4x4? If so, have you tried it in 4WD mode? Does the trans fluid smell burned and/or is it black? If you check the fluid level (idling in Park), does it read higher than normal?

GM sir!

Yes the truck does not move in reverse or drive.

Right before the truck stopped moving in gear on its own ability, I had reached a point where I would rev the motor to 2k RPM, transmission would engage and the truck would move enough to get around a parking lot.

At this point I can put it into gear and it's not moving anywhere. It feels like free revs and I can tell that the brakes are not being applied as I was watching that and had someone looking at the rear lights to make sure it wasn't braking.

In neutral the truck moves if pushed.

I tried the 4x4 mode which functions normally and engages, but transmission was slipping (I tried this when the truck would move on it's own ability). Now 4x4 does not engage and the 4x4 light just blinks like it's not engaged.

Yes, the transmission dipstick which located on the passenger side reads higher than normal, the fluid smells terrible similar has a prominent burnt odor. The fluid still appears clean and not black or dirty.

 

[transe]

GM sir!

Yes the truck does not move in reverse or drive.

Right before the truck stopped moving in gear on its own ability, I had reached a point where I would rev the motor to 2k RPM, transmission would engage and the truck would move enough to get around a parking lot.

At this point I can put it into gear and it's not moving anywhere. It feels like free revs and I can tell that the brakes are not being applied as I was watching that and had someone looking at the rear lights to make sure it wasn't braking.

In neutral the truck moves if pushed.

I tried the 4x4 mode which functions normally and engages, but transmission was slipping (I tried this when the truck would move on it's own ability). Now 4x4 does not engage and the 4x4 light just blinks like it's not engaged.

Yes, the transmission dipstick which located on the passenger side reads higher than normal, the fluid smells terrible similar has a prominent burnt odor. The fluid still appears clean and not black or dirty.

Sounds like you might have lost your line pressure. There is no single clutch that (if failed) would give both no Drive and no Reverse, so either you have multiple clutches that are failed, or you have little or no line pressure, or you have a failure in the transfer case / axle.

But you didn't find any trans faults, which puzzles me, since with loss of line pressure, or internal slippage (within the trans), you should set a fault code.

I would suggest:
1) Check whether the Park position locks the truck from rolling. If the truck will roll in Park, then the problem is in the transfer case or rear axle.
2) Drop the trans oil pan, and check both filters. Make sure the spin-on filter is snug, not loose or fallen out. Check that the main (flat) filter is not split open along the side seam, not cracked at the base of the plastic snout, and check that the snout is pushed up THROUGH the seal in the pump housing (not just resting against it). Check that the metal flange on that seal is FLUSH against the pump casting all the way around (not loose, not tilted in the bore). Check for debris in the pan or on the magnet.
3) If the filters are OK, then you probably have a stuck main regulator valve (inside the pump assy), one or more burned clutches, or both. Trans will need to be removed and torn down to inspect for damage.

 

[SFTwinTurbo]

Sounds like you might have lost your line pressure. There is no single clutch that (if failed) would give both no Drive and no Reverse, so either you have multiple clutches that are failed, or you have little or no line pressure, or you have a failure in the transfer case / axle.

But you didn't find any trans faults, which puzzles me, since with loss of line pressure, or internal slippage (within the trans), you should set a fault code.

I would suggest:
1) Check whether the Park position locks the truck from rolling. If the truck will roll in Park, then the problem is in the transfer case or rear axle.
2) Drop the trans oil pan, and check both filters. Make sure the spin-on filter is snug, not loose or fallen out. Check that the main (flat) filter is not split open along the side seam, not cracked at the base of the plastic snout, and check that the snout is pushed up THROUGH the seal in the pump housing (not just resting against it). Check that the metal flange on that seal is FLUSH against the pump casting all the way around (not loose, not tilted in the bore). Check for debris in the pan or on the magnet.
3) If the filters are OK, then you probably have a stuck main regulator valve (inside the pump assy), one or more burned clutches, or both. Trans will need to be removed and torn down to inspect for damage.

Hello TransEngineer,

Where I left off was the truck was not moving in drive or reverse, I had driven it a good 10 miles in the limited mode which doesn't let you exceed 15mph after that the truck didn't move any direction.

Since then I replaced the transmission with a used one and did the service to the unit and now the truck moves but it's slipping like crazy for example I press the pedal and the mirror reva but the transmission doesn't respond, only in lower rpms it seems to catch. I didn't change out the torque converter, in your experience could I have messed up the TC and now it needs to be replaced?

I appreciate your help!

 

[transe]

Hello TransEngineer,

Where I left off was the truck was not moving in drive or reverse, I had driven it a good 10 miles in the limited mode which doesn't let you exceed 15mph after that the truck didn't move any direction.

Since then I replaced the transmission with a used one and did the service to the unit and now the truck moves but it's slipping like crazy for example I press the pedal and the mirror reva but the transmission doesn't respond, only in lower rpms it seems to catch. I didn't change out the torque converter, in your experience could I have messed up the TC and now it needs to be replaced?

I appreciate your help!

So do you still have no faults and no CEL? It is possible that the converter has failed, but I would have expected you to find metal debris in it when you moved it to the new trans. Could be a stripped spline on the turbine hub, for example, but that would not be a common failure (that I'm aware of, at least).
See if you can borrow a scan tool that will read input (turbine) and output speeds from the trans. Then, when the truck's not moving (at a stop, engine running, in gear) check those speeds. If you have both turbine and output speeds above zero, then failure is in the transfer case or axle (somewhere AFTER the trans). If both speeds are zero, then the trans is NOT slipping, so problem would be somewhere in the converter, flexplate, or input shaft. If output speed is zero but turbine speed is above zero, then trans is slipping internally. At that point, you'd probably want to check Line Pressure and compare it to Desired Line Pressure (again, reading those values using a scan tool).

 

[RockinTTrucking]

I had that prob. With mine 2014 3500 dually pump in transmission was weak I do alot of towing so put a road ripper 3000 in from certified transmission 7000 miles on it still same dang issue no one can seem to find the prob. Yet