2018 Ram 6.4l Hemi Towing Issues

[Toddz]

I appreciate the advise. As I mentioned in one of my earlier posts, my driveway is pretty steep and when I approach I manually shift to 1st gear but still have a problem with power. It seems to start off fine with higher RPM’s then just seems to die out to appoint where the RPM’s drop way down

Are they dropping to 4,000 rpm and staying there? It looked like that is what happened on TFL and my thoughts are the transmission knowing when it doesn't have enough to upshift, just hangs at peak torque.

 

[Ribtipram]

I appreciate the advise. As I mentioned in one of my earlier posts, my driveway is pretty steep and when I approach I manually shift to 1st gear but still have a problem with power. It seems to start off fine with higher RPM’s then just seems to die out to appoint where the RPM’s drop way down

Man thats crazy. If you figure it out make sure to post back and let us know. Do you have the torque app or something similar maybe get some vitals when this is going on. Mostly timing and such.

 

[Ribtipram]

I will also say that some of the above post are correct. Myself included we are at the all in for our trucks with the 3.73 gear set. Im mostly in il so i do not deal with a lot of it but when i travel out of state the truck is working a lot harder.

 

[Jversagejr]

Are they dropping to 4,000 rpm and staying there? It looked like that is what happened on TFL and my thoughts are the transmission knowing when it doesn't have enough to upshift, just hangs at peak torque.

I am actually starting out over 4,000 rpms when it drops into 1st gear and then the RPMs drop way down between 2 to 3000 rpms and power goes way down.

 

[Toddz]

I am actually starting out over 4,000 rpms when it drops into 1st gear and then the RPMs drop way down between 2 to 3000 rpms and power goes way down.

If you are keeping your foot in it, it shouldn't drop like that. It sounds like there is some kind of issue.

 

[Ribtipram]

Hey op anything come from this

 

[Jversagejr]

Not yet as I have an appointment scheduled. Will let you know.

 

[2018 Hemi]

I towed a 1200# fifth wheel 1200 miles from Ohio to Florida and never had to downshift at all. The truck shifted back and forth great by its self, on grades it would run up to 4000 rpms. Used 89 octane while towing. 2018 6.4 373 gear

 

[Jversagejr]

I have an appointment scheduled for next Friday. I am hoping it is something with the programming on the transmission when it was replaced. I will give an update after the appointment.

 

[RamCares]

I have an appointment scheduled for next Friday. I am hoping it is something with the programming on the transmission when it was replaced. I will give an update after the appointment.

If you are in need of any additional support while working with your dealer, please be sure to send us a private message!

Mark
RamCares

 

[GsRAM]

I have an appointment scheduled for next Friday. I am hoping it is something with the programming on the transmission when it was replaced. I will give an update after the appointment.

Looking forward to hearing they hopefully found the problem and fixed you up. Good luck Sir.

 

[Jversagejr]

If you are in need of any additional support while working with your dealer, please be sure to send us a private message!

Mark
RamCares

Thank you very much and will do. Hopefully they can figure out what is wrong.

 

[Jversagejr]

Looking forward to hearing they hopefully found the problem and fixed you up. Good luck Sir.

Thanks and hopefully they will find an issue

 

[GsRAM]

Thanks and hopefully they will find an issue

I'm praying they do for you Sir, so you can put this behind you and enjoy the truck and trailer. Something has got to be wrong. Even with the weight of your rig, it should still pull hard. Mine always has.

 

[RamCares]

Thank you very much and will do. Hopefully they can figure out what is wrong.

We hope for the same, looking forward to seeing your next update!

Mark
RamCares

 

[Jversagejr]

Well I took my truck to the dealer yesterday to be checked out and was told there was nothing wrong. After further discussing what I was experiencing with the service manager and a head mechanic. The mechanic, who had over 30 years experience basically told me the 6 speed transmission is the issue. He said when going up a steep incline and the transmission down shifts from 2nd to 1st gear it will start off fine and then will go into what he called a 2nd purloin (not certain if spelled correctly) to protect the transmission. This is where the transmission will not allow the engine to over rev. He also said the transmission is really not suitable to handle the top end power of the 6.4 Hemi.

Since a Diesel is out of the question right now, I guess I have to stay out of the steeper hills. Other than the hills the truck pulls fine with plenty of power.

I am wondering if a transmission tune would held correct this issue?

 

[ramffml]

This:

He also said the transmission is really not suitable to handle the top end power of the 6.4 Hemi.

is incompatible with this:

I am wondering if a transmission tune would held correct this issue?

I would not do it. Just live with it or trade it in for a 2019 with the 8 speed.

 

[Jversagejr]

Yes he said the transmission is incompatible as not designed to handle the top end power of gas motor. Why would you not recommend a custom transmission tune? Do you think it could do damage?

 

[crash68]

Yes he said the transmission is incompatible as not designed to handle the top end power of gas motor. Why would you not recommend a custom transmission tune? Do you think it could do damage?

If the RFE68 can be built to hold up to modified Cummins, there's no reason why the similar can't be done to the RFE66.
Beefing the trans and tuning it is not going to solve your power problem. Your most likely looking at needing to make more power, re-gear the truck or both. Did you ever get an actual loaded weight of the truck/trailer?

 

[Jversagejr]

The loaded weight of the trailer was around 9800 lbs which is still under the rated amount. The mechanic also said the weight of the trailer is not an issue. As for the Cummins, he said because it makes it torque at a lower rpm range the transmission does not have to shift down to 2nd or 1st as to where it goes into this safe mode