2018 RAM 6.7 Cummins Aisin: Who's On First?

[Tuesdak]

I have been driving "around" this since I got the truck simply trying to park it in the driveway. I have to cut the throttle for it to shift into 1st without chirping the tires on this grade. This is what happens if I maintain a steady throttle. The botched/delayed 2-1 shift sets off the traction control. It's possible it's in 3rd trying for 1st?

I believe @TFucili also has a similar problem.

This is prior to the TSB 21-043-19 Aisin flash that @EZeis pointed out.

 

[TFucili]

Yessir, the infamous false neutral 2-1 slip/slam. The other day it did it as I turned off of US60 onto South Vulture Mine Rd where there is a harsh transition I slowed down for. It actually got into that false neutral with the revs climbing for the longest it has ever done it. I had to jump out of it as traffic approached, and then it finally slammed into first with the ringing driveline to match. Little Miss Aisin, she's a beauty

 

[AH64ID]

That's not something I've experienced with mine.

I have plenty of 2-1 shifts while camping with it slow and throttle applied, even on dirt it doesn't slip the tires.

 

[DeansRedRam]

I've never had anything like that with my Aisin either.

 

[EZeis]

Over 24k on my 2018 3500 srw and nothing like that has remotely happen. I do get the 1-2 shudder almost every time. Heard they all do it. Supposedly cause it's shifts at peak torque 1-2. Annoying, especially when passengers ask about it.

I did get the tsb reflash done the other day for the 2018's. Haven't towed yet but trans seems to shift better.


Earl

 

[dieselshadow]

My ‘18 has done nothing of the sort. Most of the time it’s a smooth shifter. Every now and again it may do something a bit funky, but nothing like that. It’s slow to go into gear like Fwd to Rev, slow to go into D from P, but it’s predictable.

I can say I’m not impressed with the the first applied exhaust brake after starting. I don’t believe this is an Aisin issue. It won’t use the EB after starting the engine until it’s been called for a few times. After it actually engages the EB, it works flawlessly afterwards. I’ve had the truck damn near run away going downhill until it “wakes up” and actually engages the EB. Again, once the EB works, it’s fine for the rest of the that drive cycle.

 

[EZeis]

My ‘18 has done nothing of the sort. Most of the time it’s a smooth shifter. Every now and again it may do something a bit funky, but nothing like that. It’s slow to go into gear like Fwd to Rev, slow to go into D from P, but it’s predictable.

I can say I’m not impressed with the the first applied exhaust brake after starting. I don’t believe this is an Aisin issue. It won’t use the EB after starting the engine until it’s been called for a few times. After it actually engages the EB, it works flawlessly afterwards. I’ve had the truck damn near run away going downhill until it “wakes up” and actually engages the EB. Again, once the EB works, it’s fine for the rest of the that drive cycle.

My eb on my 2018 has no issues. Run it all the time. I don't use the auto mode. Start the engine and then I push the tow/haul and eb switches.


Earl

 

[dieselshadow]

I use the EB religiously. It’s part of the start-up routine to activate it prior to putting the truck into gear. I don’t use TH all the time due to my 4:10 gears and it’s very aggressive and it takes away from fuel economy when empty. When loaded, it’s great. Still, the EB doesn’t work until it does. Then it’s fine. No codes....

 

[DeansRedRam]

About 21k on my Aisin and only "complaints" I have are I think it shifts to 2nd a little early, I would like it to rev out 1st gear a bit more.

As Dieselshadow explained earlier, the transition from R to D or P to R, or something like that, its quite slow. Not an issue for my lifestyle but something I noticed.

My last gripe would be the wacky flare up it has during the 3-4 shift, I've had a passenger or two ask me about it but I believe its due to locking of the torque converter, that's what I tell them at least.

 

[TFucili]

There are apparently enough Aisins that do it for them to have multiple reflashes that specifically address the issue, among others. Mine has been reflashed twice. No dice.

I also have SERIOUS 2-3 shudder when pulling the toy hauler. 1-2 much less so.

 

[AH64ID]

I do believe they limit back pressure on a cold motor, so that could be an issue with the EB. Personally I don’t use the EB until the motor is warmed up.

 

[JR]

A friend here just dumped his 18 for the exact same scenario after taking it in multiple times.
The first time I rode in his truck and it happened my immediate thought was something had broken. It's pretty intense.
Hopefully they figure something out to your satisfaction.

 

[dieselshadow]

I do believe they limit back pressure on a cold motor, so that could be an issue with the EB. Personally I don’t use the EB until the motor is warmed up.

That doesn’t make much sense. The exhaust break is used during cold start ups. I engage the exhaust break as part of my start up routine. Sometimes it works during warm-up, sometimes it doesn’t. It doesn’t seem to have a rhyme or reason as to when or how or depend on the temperature. I generally don’t pull out of the parking lot or parking spot until the engine reads at least 100°. This still seems to have no effect on whether or not the exhaust brake works or doesn’t. But once it does work it’s fine. I know, it doesn’t make much sense. That’s just how it works on my truck right now.

 

[JR]

The exhaust brake is only partially engaged for warm up, significantly less than when it cycles when under way.
I've always felt the EB isn't the best thing to use during warm up anyway. Adding back pressure to a cold engine can't be good long term, for similar reasons idling a cold engine isn't recommended.

 

[dieselshadow]

I use high idle and the EB for warm up to 100. After that I drive off. It only takes a few minutes. The EB varies on warm up with it being very noticeable to zero difference as though it was turned off. I don’t sit around with my truck at regular idle for any extended periods of time.

High idle has been used to warm up a Diesel engine for many many years. The use of a exhaust brake to aid in warm up isn’t a new thing either. It’s definitely nothing to be worried about.

 

[Wiredawg]

Friends,

I don't have any problems with my Aisin, but Cab and Chassis trucks have different programming, particularly with Max Tow pkg. Also having 4.88s gives me a different experience as well. Shifts are firm, but smooth.

Since the pandemic, like most, have not taken any long trips, so I'm driving it more solo. It's actually pretty fun to drive. It has brisk acceleration, and since my motor gets max TQ and max HP at lower RPMs than the P/Us SO and HO motors, and the 4.88s gives me a different experience.

One thing I miss from the past is having TDR chapter gatherings, not withstanding the pandemic. This is where groups of members could compare, test, and evaluate all aspects of our trucks. We formed the Mason Dixon Chapter in Maryland, but had members from Virginia, Pennsylvania, DC, and Delaware.

I have camping friends with 2017 and 2018 68RFE and Aisin Rams, and no complaints from either. Funny thing, they dont care to learn about their trucks.... they just like driving them and how they perform.

So, hope y'all with Aisin shifting problems find a remedy or figure out a work around. Life's too short to have nagging worries.

Cheers, Ron

 

[JR]

Cummins defines excessive idling as anything over 10 minutes below 140*. This is where the block heater and a timer will pay for itself many times over, it accomplishes the same thing for less money and doesn't unnecessarily add engine hours to the clock.

I'd also wager depending on ambient temperature the EB absolutely could introduce soot to the engine oil before the rings warm up. Enough to make a difference? Probably not, but it seems to me if they really wanted to restrict the brake as much as the EB does they would do it with programming just like they do with the high idle and to a lesser extent, the turbo.

 

[SnoKing]

I use the EB religiously. It’s part of the start-up routine to activate it prior to putting the truck into gear. I don’t use TH all the time due to my 4:10 gears and it’s very aggressive and it takes away from fuel economy when empty. When loaded, it’s great. Still, the EB doesn’t work until it does. Then it’s fine. No codes....

I do not believe that EB works at first startup, until you reach a set speed, on my 2015 with 3.42's it appears you have to get up to around 40 MPH before it comes on line. Then it works down to around 18-20 MPH. Under heavy loads in certain circumstances this could be a really big deal.

 

[SnoKing]

I do not believe that EB works at first startup, until you reach a set speed, on my 2015 with 3.42's it appears you have to get up to around 40 MPH before it comes on line. Then it works down to around 18-20 MPH. Under heavy loads in certain circumstances this could be a really big deal.

If the engine is cold soaked enough it does its warm up function if one pushes the button after start up.

 

[Wiredawg]

Cummins defines excessive idling as anything over 10 minutes below 140*. This is where the block heater and a timer will pay for itself many times over, it accomplishes the same thing for less money and doesn't unnecessarily add engine hours to the clock.

I'd also wager depending on ambient temperature the EB absolutely could introduce soot to the engine oil before the rings warm up. Enough to make a difference? Probably not, but it seems to me if they really wanted to restrict the brake as much as the EB does they would do it with programming just like they do with the high idle and to a lesser extent, the turbo.

The one good thing about having a 1/4 mile private gravel road is I have a built in warmup run without holding up traffic. My truck is parked in the mancave that never gets below 58°F, so I startup, wait 30 seconds, back out, and run 10 mph down the gravel road EVERY time. Not up to normal operating temp at the end of the road, but temp gauge starting to move. Two lane country road gives me opportunity to do easy acceleration, gradually getting up to 55MPH over about a mile. By the time I reach I10, on at full normal temp, ready to use every bit of the 100ft acceleration lanes.

So, I think I have the perfect truck warmup route and routine.

Cheers, Ron