Then there was four- digits of torque.

[kthaxton]

Again, I think adding a lower ratio and having closer ratios throughout is the goal of more speeds.....giving more ability to achieve the ideal rpm under different conditions and loads......not to change a top speed or force you to use a different rpm at a given speed.

 

[NIsaacs]

If the final drive is the same what does the 8-10 speed have to do with it? 3.42's with AISIN are the best of both worlds. If they were still available that is what I would order.

When you tow heavy with the Aisin/3.42 you use 5th, so now you only have a 5spd. With the 8spd you would use 7th, now you have a 7spd, Nice

 

[Cummins12V98]

When you tow heavy with the Aisin/3.42 you use 5th, so now you only have a 5spd. With the 8spd you would use 7th, now you have a 7spd, Nice

I am a person that has owned both 3.42 towing 29k combined and now 34-35k with 4.10’s. ONLY negative is the 3.42’s with 68rfe was not having low enough gear to get the load rolling easily. I towed in 5th same rpm as I now tow in 6th 1,750.

AISIN 3.42’s at 34-35k get the load rolling easily. I have a friend doing so at well over 100k on his 13 DRW Mega towing a DRV.

Bonus is the truck takes off on grade easily, tows at 1,750rpm at 60 in 5th, and then gets great mileage solo.

Another reason I have not bought a 2020.

Why gain so little and loose out on the best most durable Medium Duty trans on the market?

 

[kthaxton]

Why gain so little and loose out on the best most durable Medium Duty trans on the market?

You don't know the durability of a yet to be announced transmission.

 

[kthaxton]

ONLY negative is...

Well, and, the entire drivetrain ahead of the ring and pinion has a harder job to do.

 

[Cummins12V98]

You don't know the durability of a yet to be announced transmission.

true just stating my opinion

 

[Cummins12V98]

Well, and, the entire drivetrain ahead of the ring and pinion has a harder job to do.

my trans pan was very clean with 55k or so on the fluid. The ring gear still had matching at same with 65 on the clock. If it was an issue those two things wouldn’t have shown so little wear.

just my experience along with my friend running 34k at well over 100k with zero issues. His towing percentage is at least 50% and his travels are all over the US.

 

[AH64ID]

I’m sure that Ram engineers are pretty smart, but it seems to me that a 4.10 R&P with a .52 3rd OD would end up with the same overall drive ratio as .63 and 3.42s, but would reduce some stress on the trans.

I guess time will tell in what they produce.

 

[Jim W]

Well, some want to go 90mph.
Just go to Wyoming, the majority on the road goes that speed, with and without trailer. At 65 you'd be a road block there.
And think about the massive increasing trailer weights since your truck was built. Thats sure a strong point for an 8 speed.

Ozzy, I am pulling heavy with my truck now, I am close to 21,000 LBS CGW. I have pulled out west to Colorado, Utah, Arizona and New Mexico before heading for home with my 34RL, Cedar Creek in 2015. I had no issues going up I70 maintaining the speed limit in 5th gear, I could have done this in 6th gear but the EGT's would have risen above where I like them. I came home I40 because we wanted to go through Texas and Oklahoma, this was done mostly in 6th gear. My fuel mileage for this trip was 12.1 MPG with a low of 8.4 MPG when I was pulling into a 30 to 40 MPH head wind. The high was 17.9 MPG when I was in Colorado.

Regardless of speed limits out west, I will stay in the right hand lane and drive 65MPH pulling the trailer. Most of the trailer tires are rated for 65MPH max but the Cedar Creek tires are rated for 75MPH. So, I still will tow at 65MPH to be safe.

 

[Ozymandias]

Ozzy, I am pulling heavy with my truck now, I am close to 21,000 LBS CGW. I have pulled out west to Colorado, Utah, Arizona and New Mexico before heading for home with my 34RL, Cedar Creek in 2015. I had no issues going up I70 maintaining the speed limit in 5th gear, I could have done this in 6th gear but the EGT's would have risen above where I like them. I came home I40 because we wanted to go through Texas and Oklahoma, this was done mostly in 6th gear. My fuel mileage for this trip was 12.1 MPG with a low of 8.4 MPG when I was pulling into a 30 to 40 MPH head wind. The high was 17.9 MPG when I was in Colorado.

Regardless of speed limits out west, I will stay in the right hand lane and drive 65MPH pulling the trailer. Most of the trailer tires are rated for 65MPH max but the Cedar Creek tires are rated for 75MPH. So, I still will tow at 65MPH to be safe.

Thats absolutely ok to me, i just mentioned that some others want to go gastet and they will love the 8 speed with a lower final drive ratio.
Especially the ones that only tow infrequent heavy trailers and use it other ways as a daily driver.

Lower final ratio also gives longevity to the drivetrain as less rpm per mile.

 

[NIsaacs]

and then gets great mileage solo.

Have you run with your friend loaded and empty to confirm this or have records of your own two trucks?

Fuel mileage is directly related to weight, speed, RPM and power needed to maintain that speed. The 3.42 truck will use more power than the 4.10 truck at freeway speeds, say 75 mph. The power needed for the 3.42 truck might negate the lower RPM used.

 

[jhenderson]

Have you run with your friend loaded and empty to confirm this or have records of your own two trucks?

Fuel mileage is directly related to weight, speed, RPM and power needed to maintain that speed. The 3.42 truck will use more power than the 4.10 truck at freeway speeds, say 75 mph. The power needed for the 3.42 truck might negate the lower RPM used.

I agree. Guys who make their living hauling heavy are careful about RPMs, but MORE careful about boost. Boost requires fuel.

 

[RVTRKN]

After reading all the posts, as long as whatever the 8spd auto transmission is, it better be capable behind the powerfull Cummins. I have a V6/8spd in my 2018 Toyota Highlander, and I don't see any difference than the V6/6spd Tacoma (same engine) I traded in. As long as it can survive the Cummins, I'm willing to bet it won't feel much different, just like my two Toyota's.

 

[kthaxton]

Fuel mileage is directly related to weight, speed, RPM and power needed to maintain that speed. The 3.42 truck will use more power than the 4.10 truck at freeway speeds, say 75 mph. The power needed for the 3.42 truck might negate the lower RPM used.

Also, agree. Gearing is not only about engine rpm.....it's moreso about torque multiplication.

I used to have an 86 Ramcharger with 33's and stock 3.2 gearing, it was terrible. I switched to 3.92's and it was amazingly better, and mileage stayed the same. So here we have more rpm in all driving scenarios, noticeably better driveability because of the added torque, and mileage was unchanged. Free power....so to speak.

 

[Wiredawg]

I'm pretty sure folks whose GCW is 30K Lbs or more are likely getting pretty close to 9.6MPG loaded. I have 4.88s and be curious if folks with 4.44s, 4.10s, 3.73s and 3.42s are seeing the same. I think GSBrockman sees around 10MPG with 4.10s, which is in this range. I too run 65MPH loaded and see approximately 2173 RPMs.

FYI: My comment about wanting an 8 or 10 speed isn't for taller gears, it's for Ram to offer Max Tow with 4.10s with with the typical top two gears as overdrive AND the rest distributed throughout the lower gears on a 5500.

I know many of you are happy with what you have, so am I. We're talking about the next generation of trannies coming next. Regardless of the broad powerband of the 6.7L Cummins, it likes to be run loaded around 2000RPM, been and is my experience.

Cheers, Ron

 

[Ozymandias]

Correct, a vehicle is usually designed to be in direct gear at that speed that the engineers think it will be used most of the time.

 

[Cummins12V98]

Have you run with your friend loaded and empty to confirm this or have records of your own two trucks?

Fuel mileage is directly related to weight, speed, RPM and power needed to maintain that speed. The 3.42 truck will use more power than the 4.10 truck at freeway speeds, say 75 mph. The power needed for the 3.42 truck might negate the lower RPM used.

I have not but his mileage loaded is similar to mine. He does hand calc as I do.

Theory is great but I had 65k with plenty of towing time and 72k on current to know they tow the same other than taking off on grade. Yes I have every fill recorded of both trucks. The 2011 averaged 9.5 at 28-29k and current 9.0 at 33-34k. Same roads same conditions.

Here's the trans pan and diff gears at 65k on the 2011. Changed to AMZ/OIL on both around 10k and dumped just before trade in so if there were excess wear it sure would have shown in these two pics. I removed both of the MagHyted covers and re installed OE.

 

[NIsaacs]

How about some empty numbers between the two trucks? I do realize one is DEF and one isn't.

 

[Wiredawg]

I see ~11.6 empty (12.2KLbs) on the 2017 and saw ~12.2 empty (12.8K) on the 09. Both trucks only driven average 30 miles/week to keep everything tight. Only about 2% solo both trucks. Drove the 5500 to Camping World today about 80 miles there and back just to get everything up to temps. Taking 5er out next week about 150 miles out camping, slight hills, for 4 days with camping buddies.

FYI: I always see what the best tank is just once so I know, but driving to get those numbers would be painful for me as acceleration very easy and top speed 65MPH.

Cheers, Ron

 

[AH64ID]

Both trucks only driven average 30 miles/week to keep everything tight. Only about 2% solo both trucks.

Just to clarify, you tow about 78K miles a year?

Or does the 30/wk include towing?

2% solo seems almost impossible to obtain. Heck 20% solo is a lower percentage than most trucks.