6spd questions, bear with me

[Southbay]

Long time Ram owner, long time reader of this forum, first time poster.

Looking for honest opinions and also facts on the 6spd transmission behind the 5.7 from people who currently own or who have previously owned them or just anyone who is super knowledgable, which is most guys on here. I know the 8spd is superior in many ways, smoother, better MPG, better balanced gear ratios, but I am trying to find out if there are any actual problems with the 6spd (65RFE I believe). When I say problems I mean historical troublesome issues or breakdowns that can be expected in most 6spd trannies.

I have heard they can shift hard sometimes or bang around, but I am not sure if that has anything to do with the reliability of the tranny or if it just shifts harder than the 8spd so people crap on it. I remember when the 6spd replaced the 5spd, I am pretty sure it's the same tranny with some software and TC updates, and people were all excited about the 6spd, now people crap all over it since the 8spd came out.

I only ask because there are very good deals to be had on low mileage 1500's with the 6spd out there, but I also wonder why there are so many 6spd trucks out there for sale with relatively low miles. My need for the truck is not for towing, at least not anything big. I tow my son's 13' Whaler a couple times a year, maybe a small utility trailer. The truck will go on the beach in the summer and other than that get normal around town use. I commute to NYC so it will sit in the train lot the majority of the time. My current truck is a 2004 and has 120K miles on it, it has the 545RFE behind the 4.7 and hasn't given me a second of trouble and I have no issue with the way it shifts or performs behind the 4.7, in fact I like it better than when I drive my wife's Traverse with the 9spd tranny and it shifts 4 times by the time you are at 20mph. I average 2500-3K miles a year so overall MPG doesn't matter to me all that much, it'll make a road trip maybe 3 times a year and be around town driving within 10 miles from home most of it's life, so that is why the MPG increase of the 8 spd doesn't matter to me all that much.

That being said I have no desire to buy a **** of a transmission that will give me trouble. Everything I read on the 6spd is about performance and MPG, hard to find anything about if it is actually a good tranny regardless of those things. Thanks for any info... and thanks for educating a newbie to the newer gen trucks.....the 2004 has served me well, but it's time to let it go.

 

[MADDOG]

I've owned two 6 speed with a HEMI equipped trucks and never had any problem with either one.

One was used which I picked up with 32K on it and the other was brand new. I ran the first one to 140K miles and it never gave me a bit of trouble. The other one had it's life cut short by a distracted driver that totaled that truck at 23K miles.

I think a lot of what we read about those transmissions is based on higher mileage 6 spd trucks that weren't maintained properly, i.e., regularly and that were probably purchased used.

 

[kurek]

You could say the 65RFE is basically unchanged from when it was first introduced in 1999 as a 4 speed transmission. True 3rd is still generally skipped on upshifts, but acessible on downshifts or with ERS. But they made major changes to the valve body somewhere around 2005 and to the electronic controls after that... I'm sure a ton of things have changed year by year.

I had this transmission in a 4.7HO 2002 Grand Cherokee and have it now in my 2015 Hemi Ram 4wd. In both cases I'm very happy with it. The 2002 never gave me trouble, but I didn't much love how it shifted, kind of sluggish. I installed a shift kit to tighten it up and that made it change gears nice and quick, though still not harsh or abrupt. The one in my 2015 Ram shifts quick on its own from day one. Admittedly shifts aren't quite as quick as the 8 speed, I test drove three of those while shopping and that is a nicer gearbox.

But I have no problem at all with the 6 speed. Its only crime so far as I can tell is early ones had sloppy hand-offs between gears and apparently had a quality control problem on the screws that held the end plate on the valve body.. the modern ones seem just fine for an average owner. It appears that the ones that fail tend to be behind modified engines and under heavy right feet. If that describes you, hold out for an 8 speed they're going to be faster anyway. If you just run the truck as a tool and you've factored routine maintenance in, don't fear the RFE.

 

[Wild one]

Long time Ram owner, long time reader of this forum, first time poster.

Looking for honest opinions and also facts on the 6spd transmission behind the 5.7 from people who currently own or who have previously owned them or just anyone who is super knowledgable, which is most guys on here. I know the 8spd is superior in many ways, smoother, better MPG, better balanced gear ratios, but I am trying to find out if there are any actual problems with the 6spd (65RFE I believe). When I say problems I mean historical troublesome issues or breakdowns that can be expected in most 6spd trannies.

I have heard they can shift hard sometimes or bang around, but I am not sure if that has anything to do with the reliability of the tranny or if it just shifts harder than the 8spd so people crap on it. I remember when the 6spd replaced the 5spd, I am pretty sure it's the same tranny with some software and TC updates, and people were all excited about the 6spd, now people crap all over it since the 8spd came out.

I only ask because there are very good deals to be had on low mileage 1500's with the 6spd out there, but I also wonder why there are so many 6spd trucks out there for sale with relatively low miles. My need for the truck is not for towing, at least not anything big. I tow my son's 13' Whaler a couple times a year, maybe a small utility trailer. The truck will go on the beach in the summer and other than that get normal around town use. I commute to NYC so it will sit in the train lot the majority of the time. My current truck is a 2004 and has 120K miles on it, it has the 545RFE behind the 4.7 and hasn't given me a second of trouble and I have no issue with the way it shifts or performs behind the 4.7, in fact I like it better than when I drive my wife's Traverse with the 9spd tranny and it shifts 4 times by the time you are at 20mph. I average 2500-3K miles a year so overall MPG doesn't matter to me all that much, it'll make a road trip maybe 3 times a year and be around town driving within 10 miles from home most of it's life, so that is why the MPG increase of the 8 spd doesn't matter to me all that much.

That being said I have no desire to buy a **** of a transmission that will give me trouble. Everything I read on the 6spd is about performance and MPG, hard to find anything about if it is actually a good tranny regardless of those things. Thanks for any info... and thanks for educating a newbie to the newer gen trucks.....the 2004 has served me well, but it's time to let it go.

The thing that kills them is wide open downshifts like if you're passing another vehicle,and they won't take wide open runs in high gear/overdrive. As long as you don't abuse them that way,there's nothing wrong with the tranny behind a stock engine.If you like flooring it to pass,try to get in the habit of downshifting it just before you floor the skinny pedal.

 

[RLJ10X]

^Well, wasn't that a sweet little compliment.

 

[burner71]

I had and still have the 66RFE which I believe is close to the same. I drive it very hard for 230k miles when it started to slip and give gear ratio codes. It lasted much longer than I anticipated. I was able to replace it with a low mile part out and it’s been perfect.

 

[RVGuy]

I have 165k miles on my 6 speed. I have two "issues" with it, first being that if I'm accelerating gently from a stop to highway speed it feels like it's hesitating at the end of 2nd gear. Like the RPMs will stop going up for a fraction of a second and then keep going, then stop then keep going. It doesn't do this if I accelerate more briskly or if I'm in tow/haul so I figure it's more due to programming than an actual problem.
The other issue, which isn't even the transmission's fault, is how quickly the truck will clamour into the highest gear it can too quickly. I'll be cruising at 35mph and the thing will upshift all the way to 5th. If I coast down it'll stay in 4th until 20mph and my RPMs will be barely above idle. Just annoying, I usually drive in tow/haul to prevent it. Again, more of a programming issue than an actual trans issue.

Other than that I service it by the intervals in the service manual and it still shifts great and the fluid looks great.

 

[kurek]

The other issue, which isn't even the transmission's fault, is how quickly the truck will clamour into the highest gear it can too quickly. I'll be cruising at 35mph and the thing will upshift all the way to 5th. If I coast down it'll stay in 4th until 20mph and my RPMs will be barely above idle. Just annoying, I usually drive in tow/haul to prevent it. Again, more of a programming issue than an actual trans issue.

.

I think this is more about efficiency than anything. For a given displacement, an 8 cylinder engine has around 15% more swept surface area in its cylinders than a 6 cylinder engine for example. (bore and stroke differences can change that a little, but it's around 15% on a per-liter basis) - but that also means if you can run the 8 cylinder engine 15% slower then the total linear sweep per time interval is the same.

The more cylinders your engine has the more efficiency you can gain by running it slowly with the side effect that it's also typically going to be more quiet and put less wear on all the rotating parts, internal and external, per hour of operation.

I do wish there was an easier way than the ERS buttons to interact with the trans, like if there was an economically justifiable way to throw flappy paddles on or even if there was a "SPORT/ECON" button like some Japanese cars used to have..

 

[RVGuy]

I think this is more about efficiency than anything. For a given displacement, an 8 cylinder engine has around 15% more swept surface area in its cylinders than a 6 cylinder engine for example. (bore and stroke differences can change that a little, but it's around 15% on a per-liter basis) - but that also means if you can run the 8 cylinder engine 15% slower then the total linear sweep per time interval is the same.

The more cylinders your engine has the more efficiency you can gain by running it slowly with the side effect that it's also typically going to be more quiet and put less wear on all the rotating parts, internal and external, per hour of operation.

I do wish there was an easier way than the ERS buttons to interact with the trans, like if there was an economically justifiable way to throw flappy paddles on or even if there was a "SPORT/ECON" button like some Japanese cars used to have..

I see what you're saying and it does make sense. It really wouldn't bother me if I didn't need to push the throttle so far to get it to downshift and accelerate. Once it's putting around at less than 1000rpm I can't seem to accelerate without almost flooring it, then when it does eventually downshift I end up going way too fast and making the truck bark.
Being in a tiny little town, I don't really like doing it because it does look bad... Still love the truck though, it's a pretty minor thing.
I've heard that the 8 speed is much more responsive to downshifting when you call for more throttle, looking forward to that next truck.

 

[kurek]

I wonder if maybe your throttle position sensor is getting old, or something - my 6 speed doesn't seem to be unresponsive at the level you describe. I guess I could call it sort of unresponsive and it does love keeping the engine rpm low when I'm not giving it pedal but it gets to work fast enough - subjectively - when I ask it to.

There might be a throttle position calibration procedure you could do, or have inspected next time you're in for an oil change?

 

[RVGuy]

I wonder if maybe your throttle position sensor is getting old, or something - my 6 speed doesn't seem to be unresponsive at the level you describe. I guess I could call it sort of unresponsive and it does love keeping the engine rpm low when I'm not giving it pedal but it gets to work fast enough - subjectively - when I ask it to.

There might be a throttle position calibration procedure you could do, or have inspected next time you're in for an oil change?

I did find a process to calibrate the sensor awhile ago and tried it, which didn't seem to make a difference. I believe I found it on a forum like this though so who's to say I did it right it that it's even correct though?
It would explain the sort of pause I get during acceleration out of tow/haul too if that were the case. If I ever find myself at a dealership again I'll ask them about it, last time I was there was for my coolant flush, next thing I'd probably let them do would be my trans fluid but I'm not due for that for awhile so I'll live with it, lol.