Transmission question for 6.4 guys

[Firebird]

I have always regretted trading out my 2018 heavy duty with the 6.4 (had to because I fell off the roof and paralyzed my leg), but now I’m good. My only fault I had with the 6.4 then, was the 6 speed trans. For the new trucks with the 8 speed, how do you like it? Any and all feedback is greatly appreciated!

 

[RBinNC]

I can't compare to the 6, but I own the 6.4 /8. I have no issues with it. Shifts smooth, and is powerful. I just hate the MDS but that's a different thing.

From what I've read, many feel the 8 speed really serves the 6.4 very well. Lots of good reviews.

 

[farmallboy]

It shifts A LOT AND QUICK

took practice to learn to drive it so it wouldn't be in 6,7, or 8 too early. Although I have 4.10s. Jump in one of those two sons and it will bog. BUT hitched up in tow haul and man! Super nice driving.


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[farmallboy]

I can't compare to the 6, but I own the 6.4 /8. I have no issues with it. Shifts smooth, and is powerful. I just hate the MDS but that's a different thing.

From what I've read, many feel the 8 speed really serves the 6.4 very well. Lots of good reviews.

I will second the smooth aspect. It does shift super nice and light even hooked up


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[star_deceiver]

Night and day better, in every circumstance. If you’re worried about it bogging in 8th just mash the go pedal and it will skip down multiple gears and you're off.... even 8th to 2nd mash and fly is smooth!

 

[mlrtimemach]

My truck has 373 gears. Pulls our 28ft camper just fine as did the 6 speed. Biggest difference I see is it is gutless backing up an incline with or without the camper. My 2015 short box with 373 an a 6.4 seemed to back right up the driveway. This 2019 long box with the 6.4 an 373 seems to require more gas pedal.
I'd say maybe it's just me. But when I have to lock it into 4 wheel drive the second I get off the pavement compared to my 2015 when I only had to lock it in when the ground was damp tells me there's a difference. Other than that I don't feel much difference

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[Papa Red]

I have the 8 speed and it's great. Seems like you're always in the right gear. I have no complaints.

Red

 

[Firebird]

Thanks for the feedback!

 

[NH RAM]

I also have the 8 speed, which I was waiting for in the HD's due to the towing reviews being, well, underwhelming with the 6 speed behind the 6.4. Coming from a 2016 1500 with a 5.7 and the 8 speed, I had high hopes for the 6.4 and 8 speed and so far it has not disappointed. I opted for 3.73 as I didn't see a need for 4.10's and they're unicorns around here anyway. the truck moves out when you want it to and doesn't hunt while towing.
The reverse gear is 4.45 in the RFE and I believe a 3.32 in the ZF, so there's that in the loss column, but the significant improvement in forward gearing far outweighs that.

 

[Travelin Ram]

Just test drive one and all your questions will be answered.

Take your checkbook.

 

[tjfdesmo]

I also have the 8 speed, which I was waiting for in the HD's due to the towing reviews being, well, underwhelming with the 6 speed behind the 6.4. Coming from a 2016 1500 with a 5.7 and the 8 speed, I had high hopes for the 6.4 and 8 speed and so far it has not disappointed. I opted for 3.73 as I didn't see a need for 4.10's and they're unicorns around here anyway. the truck moves out when you want it to and doesn't hunt while towing.
The reverse gear is 4.45 in the RFE and I believe a 3.32 in the ZF, so there's that in the loss column, but the significant improvement in forward gearing far outweighs that.

Disappointed to see they are running a taller reverse ratio, but it's still way better that the 2.21 reverse in my '05 CTD with 48RE. Required using 4 LOW to back up a hill.

 

[mlrtimemach]

So it wasn't me I'm not crazy. Why in the hell would they change the dang gear like that. People back stuff up all the time. That's one thing I miss most about my 2015, I could back it up with the same gusto it had goin forward.


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[RandomRam]

6.4, 8 speed, and 4.10 gears. I love it. I have not towed with it yet, hauled at max several times and it handles with ease. It’s stupid fast for a truck that weights 7k. Transmission is never in the wrong gear and holds gears when it needs to. It’s nice to be driving at low speed and not have it shift up and lug.

My opinion the coil sprung 2500 with the 6.4 combined with the 8 speed is the perfect HD truck for the owner that needs a capable hauler on the weekend and a well mannered daily driver during the week. It rides good, gets decent fuel mileage, and is fun to drive.

 

[Bisley45]

6.4, 8 speed, and 4.10 gears. I love it. I have not towed with it yet, hauled at max several times and it handles with ease. It’s stupid fast for a truck that weights 7k. Transmission is never in the wrong gear and holds gears when it needs to. It’s nice to be driving at low speed and not have it shift up and lug.

My opinion the coil sprung 2500 with the 6.4 combined with the 8 speed is the perfect HD truck for the owner that needs a capable hauler on the weekend and a well mannered daily driver during the week. It rides good, gets decent fuel mileage, and is fun to drive.

My thoughts exactly! I enjoy driving this truck, it's surprisingly quick!

 

[PJ Snyder]

I have a question regarding axle ratios.
Does the 4.10 rear end use a lot more gas than the 3.73. Also at highway speeds does the 4.10 tend to rev a great deal over the 3.73?

 

[Marley]

I have a question regarding axle ratios.
Does the 4.10 rear end use a lot more gas than the 3.73. Also at highway speeds does the 4.10 tend to rev a great deal over the 3.73?

The 4.10 may use slightly more fuel to accommodate higher RPMS at the same highway speeds as the 3.73 but is appealing to those that tow......higher RPMS equate to greater horsepower and less gear searching when towing weight.

 

[14hemiexpress]

I like it. Its much better than the 1500s I have owned with the RFEs. It smooth and doesn't skip a beat and really get this big truck moving.

 

[PJ Snyder]

The 4.10 may use slightly more fuel to accommodate higher RPMS at the same highway speeds as the 3.73 but is appealing to those that tow......higher RPMS equate to greater horsepower and less gear searching when towing weight.

 

[PJ Snyder]

Thanks for your reply.

 

[WoodGuy]

3:73 to 4:10 is about a 200-250 rpm jump at 70 mph