Potentially upgrading to 6.4 need input

[PCT]

Hey all,
I am kinda over my 4.7, and i want to upgrade to a 2500 6.4. What do yall recommend. When i bought my 4.7, my Ford 6.0 blew up and needed something, so i didnt do much research. So i ended up with a 4.7 w/ 3.55 gears, no CARB compliant upgrades ext.

What are some things that i need to look out for when looking for 6.4 is it reliable? Are all gearing options suitable? This will be a daily. Is the 6 Speed Solid, or a fail?

Also what are some good mods yall recommend?

 

[1500ram12]

I've owned 2 6.4Ls, a 2015 and now a 2018. I used them as daily driver's. I've had zero issues with them so far. Currently I have about 16700 miles on my 18. Although the 68rfe trans isn't the best it's a decent trans for the 6.4L. For the cummins definitely not. During the summer I run 35's and in the winter run roughly a 34" tire. Depending on your commute gas mileage will vary. I drive about 11 miles 1 way. So I hover around 12 during the summer. Was closer to 15 before installing a borla xr-1 muffler.


2018 Ram 2500 6.4L Hemi Tradesman

 

[crash68]

If your concern is the 6spd RFE trans, get a '19+ 6.4l 2500 with the ZF 8 spd transmission. A much better transmission especially if/when your towing. About the only criticism the 8spd gets is the guys that whine like beetchs about the shift knob. Shift by wire is here to stay on all vehicles, doesn't matter what you use to shift the trans they'll all be done by wire soon enough.

 

[PCT]

If your concern is the 6spd RFE trans, get a '19+ 6.4l 2500 with the ZF 8 spd transmission. A much better transmission especially if/when your towing. About the only criticism the 8spd gets is the guys that whine like beetchs about the shift knob. Shift by wire is here to stay on all vehicles, doesn't matter what you use to shift the trans they'll all be done by wire soon enough.

Is the 6RFE something to be concerned about? Does it fail? Or just not a good combo for 6.4 in drivability?

cant afford '19 at this point

 

[1500ram12]

Is the 6RFE something to be concerned about? Does it fail? Or just not a good combo for 6.4 in drivability?

cant afford '19 at this point

68rfe is fine for the 6.4L. Only time you could have an issue would be if you were constantly towing max weight or beating on the truck or adding a lot of extra power. Granted any trans can fail at any point just under normal driving conditions


2018 Ram 2500 6.4L Hemi Tradesman

 

[PCT]

68rfe is fine for the 6.4L. Only time you could have an issue would be if you were constantly towing max weight or beating on the truck or adding a lot of extra power. Granted any trans can fail at any point just under normal driving conditions


2018 Ram 2500 6.4L Hemi Tradesman

Which one is behind the 6.4? 66 or 68? I plan on 35's intake, and hemifever, nothing much more in terms of performance.

 

[ScrubsR1]

66

 

[mtofell]

66rfe = 6.4 Hemi, 6spd, up to 2018 - 2019 onward has 8spd
68rfe = most Cummins HD diesels

2018 and prior 6spd tranny- Same gear ratios which sucks for the gasser towing heavy. Mainly, the spacing between first and second too far (works great for a diesel that makes all its power at the low end - sucks for a gasser). You get stuck not being able to hold second and constantly jumping back to first. This really is only a problem when towing heavy - maybe above 8K or so.

Gearing options are pretty close at 3.73 or 4.10. I think far too much gets made of this minor difference. If you want to really do it right, re-gear up to 4.56 or 4.88. Lots of people have done that and report major improvement both towing and daily driving.

Newer 8spd gets great reviews and solves all the spacing issues (at least that's what I've read around here). If I were shopping there is no way I'd buy the 6spd if I ever planned to tow much.

Otherwise, these are great trucks. From hanging out here pretty much daily for the last 5+ years I really can't say there are huge/widespread problems. Just normal things that can come up with any trucks.

 

[ripping r]

All autos are junk. when it goes out dont put stock junk back in. get it rebuilt with aftermarket parts and be done.

 

[1500ram12]

Which one is behind the 6.4? 66 or 68? I plan on 35's intake, and hemifever, nothing much more in terms of performance.

Like I had mentioned earlier, I run 35's and have a exhaust. Honestly I'd just get high flow filter replacement. I'd save the cash on a tuner and get a pedal commander. These trucks have plenty of power.


2018 Ram 2500 6.4L Hemi Tradesman

 

[PCT]

66rfe = 6.4 Hemi, 6spd, up to 2018 - 2019 onward has 8spd
68rfe = most Cummins HD diesels

2018 and prior 6spd tranny- Same gear ratios which sucks for the gasser towing heavy. Mainly, the spacing between first and second too far (works great for a diesel that makes all its power at the low end - sucks for a gasser). You get stuck not being able to hold second and constantly jumping back to first. This really is only a problem when towing heavy - maybe above 8K or so.

Gearing options are pretty close at 3.73 or 4.10. I think far too much gets made of this minor difference. If you want to really do it right, re-gear up to 4.56 or 4.88. Lots of people have done that and report major improvement both towing and daily driving.

Newer 8spd gets great reviews and solves all the spacing issues (at least that's what I've read around here). If I were shopping there is no way I'd buy the 6spd if I ever planned to tow much.

Otherwise, these are great trucks. From hanging out here pretty much daily for the last 5+ years I really can't say there are huge/widespread problems. Just normal things that can come up with any trucks.

Are the 66RFE reliable trans? i've seen people have issues with the 65RFE(I think behind the hemi) i have that on my 4.7

 

[mtofell]

Are the 66RFE reliable trans? i've seen people have issues with the 65RFE(I think behind the hemi) i have that on my 4.7

LOL.... I'm probably the wrong guy to ask. Mine blew up at 38K miles under zero load - sitting on the freeway in stop/go traffic while towing/hauling nothing. It was rebuilt as has generally been okay, ironically until 2 days ago when it just went in "limp mode" which means it was just stuck in 4th gear. After turning the truck on/off it seems fine but there could be another round of problems coming.

All this being said, my experience does not seem indicative of the tranny as a whole. I've read about very few failures and problems as a whole. I guess I'm just lucky

 

[PCT]

Little update, i found one i really like, and i found out it has 4.10's which seems to be the better option!

 

[392DevilDog]

I have nothing but good to say about my 2015 6.4l with 127,000 miles on it.

We just went out the gameland roads and played in the snow. Turning of ESC and letting that Hemi make the anti spin work up an icy hill is music to the ears. And blasting up a snow covered hill you just watched a jeep have trouble with is awesome. Especially hearing the wife and 2 kids giggle all the way.

As mentioned the 6.4l Hemi with the 66RFE is a good combination. It would be perfect if they allowed the manual shift to hold the gear. It limits how high it will shift, but still lets it downshift.

The motor is very similar to my 8.0l V10, I just wish the Hemi had the manual and clutch my V10 Magnum is mated to.

If you could just hold 2nd rather than slam shift to 1st, it would be great.

That said, as mentioned, the 8 spd fixes it all...

Mine has 3.73 gears, although I wanted the 4.10s, I haven't been disappointed.