Raced a 16 Silverado 2500hd-6.0...LOST

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

theviking

Senior Member
Supporting Member
Joined
Apr 7, 2014
Posts
1,176
Reaction score
605
Ram Year
2015
Engine
Hemi 6.4
Hell, the 66 is a 68 stuffed in a 545 case. Lol


Sent from my iPhone using Tapatalk

Well, sort of. It appears to be a bit of a hybrid, at least according to Allpar articles. This is from another forum post some time back:

Doing some reading on the 68 vs 66 from another Allpar article.

All three automatics have a one-piece case, electronic control, two stage hydraulic pump (which shuts the secondary side at higher speeds, for efficiency), and similar valve bodies. They all use three planetary gearsets, three driving clutches, three holding clutches, and an overrunning clutch. The 66 uses some parts derived or taken from the 545 (mainly in the front: torque converter and pump; overdrive, underdrive, and reverse clutches; and valve body), and some derived or taken from the 68 (low/reverse clutches, planetary gearsets, and 2C clutch).

The 68RFE and 66RFE automatic transmissions for Ram trucks

So, in comparing to the 68RFE it appears that 3rd and 5th would be the weakest link since the underdrive/overdrive and 4c clutches are not upgraded in the 66RFE. The low range and 2c clutches (1st and 2nd) are upgraded per the article. It's unclear (to me) if the 4c and UD/OD clutch assemblies from the 68 could be retrofitted into the 66RFE, but would seem like a logical place to start during a rebuild. Per Brandon, 4th would seem to be the best gear on the dyno since no clutches are engaged. I will have to follow up with HF to see what his actual concern is.

68RFEClutchOp3_zpsgc7nysjw.jpg
68RFEClutchOp2_zps13q3vz8w.jpg
 

Danno

Senior Member
Joined
Mar 15, 2016
Posts
490
Reaction score
102
Location
Mid Atlantic
Ram Year
2016 Power Wagon
Engine
6.4
Danno, why don't you remind us again how you are such an expert in this area. Oh yea, you never did because you can't...

30k rated capacity is only available with the Cummins/Aisin combo. The 2500/3500 6.4 HD is currently rated at a max towing capacity of around 16k. How do you know the statement you quoted wasn't referring to the Cummins HD models since that is the ONLY motor available rated anywhere near the 30k? How exactly do you know the ZF 8 speed can't handle 16k? Still waiting for some justification on your statement that the clutches can't handle the 6.4's output. As ST said, you haven't provided a shred of evidence to back up any of your claims. Just your usual BS, and you're not even good at that.

How many 8HP do you know of that's mated to a HD? How about mated to a 6.4? How many applications did ZF have for the 8HP in trucks? 8HP is a passenger car transmission as ZF shows, why is it so hard to understand? The 8HP70L was designed to be a commercial light vehicle transmission for a weight of 16k if I recall. Why would they design a new transmission if the current would work. Do you also believe the Ford coyote is a 4 legged dog?

Remeber how the 360hp/380ft lbs 6.0 stomped the 6.4 and still does to this day?
 
Last edited:

loveracing1988

Senior Member
Joined
Jul 4, 2013
Posts
3,505
Reaction score
913
Location
Clarkston, MI
Ram Year
2020
Engine
6.7 Cummins
How many 8HP do you know of that's mated to a HD? How about mated to a 6.4? How many applications did ZF have for the 8HP in trucks? 8HP is a passenger car transmission as ZF shows, why is it so hard to understand? The 8HP70L was designed to be a commercial light vehicle transmission for a weight of 16k if I recall. Why would they design a new transmission if the current would work. Do you also believe the Ford coyote is a 4 legged dog?

Remeber how the 360hp/380ft lbs 6.0 stomped the 6.4 and still does to this day?
Do you have something wrong with your brain that doesn't let you comprehend things? Where in here has anyone said the 8hp70 should be in the HD's? Everyone has said the 8hp90 should from the hellcat should be in these trucks and yet you keep circling it back around to the 8hp70 claiming it can't handle the torque because it isn't installed in any HD truck. According to your logic it should have never been installed in the 1500 trucks because it had never been in a truck before.

Sent from my Nexus 6 using Tapatalk
 

Danno

Senior Member
Joined
Mar 15, 2016
Posts
490
Reaction score
102
Location
Mid Atlantic
Ram Year
2016 Power Wagon
Engine
6.4
Do you have something wrong with your brain that doesn't let you comprehend things? Where in here has anyone said the 8hp70 should be in the HD's? Everyone has said the 8hp90 should from the hellcat should be in these trucks and yet you keep circling it back around to the 8hp70 claiming it can't handle the torque because it isn't installed in any HD truck. According to your logic it should have never been installed in the 1500 trucks because it had never been in a truck before.

Sent from my Nexus 6 using Tapatalk

Sometimes you need to use crayons. Ok we have the 8Hp transmission series (8hp45-8hp90). Now with the 8hp series ZF designed the truck 8HP70L (notice the L) for light commercial vehicles with a capacity of I believe 16k. Now why would they design a new transmission if they could take a 8hp90 and use it? :wtf2:

The 8hp series has been in compact trucks and the 1500.

Maybe if there was a 8 speed available for the 6.4 it could keep up with the GM 360hp 6.0, thats pretty sad. :roflsquared:
 

drittal

Senior Member
Joined
Apr 24, 2015
Posts
1,557
Reaction score
636
Location
E. Montana
Ram Year
2013
Engine
6.7
What does it matter? The 90 has been with FCA for 3(?) years now and Ram flat out said in 2015 the short answer is we won't see one in an HD. Being rated for a ~16k box van and a HD truck with a GCWR of ~23k are not the same. Yes it's not 30k, but it's also 44% more. Maybe in the future, sure. But it sounds like the 90 is not currently perceived to be up to the task.

Ram currently has a transmission up to the task with a better ratio, they just don't offer it behind the gas unless you go cab and chassis.


Sent from my iPhone using Tapatalk
 
Last edited:

smurfs_of_war

Senior Member
Joined
Oct 29, 2013
Posts
2,116
Reaction score
1,263
Location
Swift Current, Saskatchewan
Ram Year
2020
Engine
Hemi 6.4
Sooo... let me play devils advocate to BOTH sides. What if the absence of the ZF transmission in the HDs is simply because they don't need it? I am only speculating, but hear me out.
Look at the pattern for the HDs across the board. Is the 10 speed in the GM or Ford's? No. Why? IMHO it's because it's not needed. Why? Fuel efficiency requirements. The 8 speed is a great trans. What's the biggest selling feature of it? Improved fuel efficiency. The new 10 speed with Ford? Again- improved fuel efficiency. The HD segment does not have to meet these standards. The ZF kits will take some reworking to get into these trucks and as drittal pointed out in his link- be rated to hold this weight. That costs money. Big bucks in fact. Then there is the required testing to make sure they'll survive.

Coming soon I have no doubt that 2500/3500 series trucks will fall under the same umbrella as 150/1500 series and passenger cars. Until then, the RFE trans are a fairly stout proven design that is cost effective to continue in the HD trucks. I don't see any of them changing until they have to.

Sent from my SM-G925W8 using Tapatalk
 
Last edited:

SouthTexan

Senior Member
Joined
Jan 24, 2015
Posts
2,149
Reaction score
1,303
Ram Year
2014
Engine
408 CTD
It's easy to back the statement of the 8hp is not suited for HD use. Show where it is used in anything other than passenger cars, a Ram 1500 and a compact truck. The proof is provided its not capable by the fact it's not used and the fact that a special 8HP70L was designed for light commercial use. If it's capable then prove it.

Why get all wrapped up in the use of Heavy Duty, do you think the Ford 5.0 coyote is really a four legged dog under the hood??? Must if the use of the Heavy Duty is so upsetting. :roflsquared:

For the last time here is the specs and application as per ZF (the company that designed and engineered the 8HP), one MAY think they would be the foremost authority. Note two different categories car (8HP) and truck (8HP70L) as per ZF.

Stars by ZF - ZF Friedrichshafen AG

Stars by ZF - ZF Friedrichshafen AG

My use of the 6.4 is in a power wagon, I don't tow as its capacity is reduced and use it as a daily driver and trails. Its a good passenger engine but not a work horse. Most like to brag about the 6.4 being the most powerful and the numbers bring a lot of buyer, they fall for the advertising and want mall parking lot bragging rights.

It's just like the 6.7, 2500 and 3500 number are advertised to compete with the others in the market. Your not getting those number, torque management takes over. 4500 and 5500 have the same 6.7 but reduced # rating. Bragging rights is all it is.

All that rambling and you still could not show any factual evidence to back you your "the 8HP clutches can't handle the 6.4L HD". Still waiting......:roflsquared:
 

SouthTexan

Senior Member
Joined
Jan 24, 2015
Posts
2,149
Reaction score
1,303
Ram Year
2014
Engine
408 CTD
The short coming of the 6.4 isn't the motor but the gearing in the 66rfe. That said, I provided a quote from 2015 where a Ram Rep said there won't be an 8sp in the HD line because they are not rated for the weights or for holding them in park in an incline. While some appear to be used in light duty commercial vehicles with 16k GVWR, the Ram 6.4 is rated for over 20k GCWR


Sent from my iPhone using Tapatalk

Sorry, but the guys at TFL lost their credibility on information with me a long time ago. About a year ago they posted some crap about the Cummins in one of their articles and I sent an e-mail to Kent giving him information on the correct information. He said thanks for the info and never went back to correct the article.

Although, they said that the rep said that the "The existing 8-speed TorqueFlight automatic transmission is not rated for heavy duty requirements of towing up to 30,000 lbs or hauling over 7,000 lbs." There is no 6.4L HD that is rated to do either of those. Also, the only 8HP in a RAM is the 8HP70, not the 8HP90.
 

loveracing1988

Senior Member
Joined
Jul 4, 2013
Posts
3,505
Reaction score
913
Location
Clarkston, MI
Ram Year
2020
Engine
6.7 Cummins
Sorry, but the guys at TFL lost their credibility on information with me a long time ago. About a year ago they posted some crap about the Cummins in one of their articles and I sent an e-mail to Kent giving him information on the correct information. He said thanks for the info and never went back to correct the article.

Although, they said that the rep said that the "The existing 8-speed TorqueFlight automatic transmission is not rated for heavy duty requirements of towing up to 30,000 lbs or hauling over 7,000 lbs." There is no 6.4L HD that is rated to do either of those. Also, the only 8HP in a RAM is the 8HP70, not the 8HP90.
I've never liked Kent, he isnt actually a part of TFL, he has his own separate YouTube channel as "Mr Truck". I think they brought him in for some added knowledge since TFL originally reviewed cars. They brought him in and he is way too opinionated and set in his ways, and for having his CDL for the heavy testing he can't even seem to set trailer brakes correctly half the time.

Sent from my Nexus 6 using Tapatalk
 

smurfs_of_war

Senior Member
Joined
Oct 29, 2013
Posts
2,116
Reaction score
1,263
Location
Swift Current, Saskatchewan
Ram Year
2020
Engine
Hemi 6.4
I've never liked Kent, he isnt actually a part of TFL, he has his own separate YouTube channel as "Mr Truck". I think they brought him in for some added knowledge since TFL originally reviewed cars. They brought him in and he is way too opinionated and set in his ways, and for having his CDL for the heavy testing he can't even seem to set trailer brakes correctly half the time.

Sent from my Nexus 6 using Tapatalk
I've watched a number of Mr. Truck's segments. His senility is showing.

Sent from my SM-G925W8 using Tapatalk
 

drittal

Senior Member
Joined
Apr 24, 2015
Posts
1,557
Reaction score
636
Location
E. Montana
Ram Year
2013
Engine
6.7
It wasn't TFL that said the 8sp wasn't going in the HD. They relayed what Ram rep told them. It doesn't change the fact that there is a transmission used in HD trucks with better gear spread. I have to believe in both cases it is a financial decision not to use either. The Aisin just for the premium and the 90 because according to Ram it isn't up the the rigors of a HD without redesign of at least the parking prawl and subsequently the entire case


Sent from my iPhone using Tapatalk
 

drittal

Senior Member
Joined
Apr 24, 2015
Posts
1,557
Reaction score
636
Location
E. Montana
Ram Year
2013
Engine
6.7
https://www.motor.com/newsletters/20121010/WebFiles/MMM_ZF_8HP_Tranny.pdf

So in 2012 Chrysler posts about the new 8sp including the 90 and put in print they won't replace HD transmissions. This is before the 6.4l even. Going on 5 yrs and still no use in the HD line even after developing the 6.4l and having to develop the gear hold programming because of the gear ratios of the 66rfe.

I have to wonder if the downfall of the ZF8 in the HD doesn't revolve around the electronic shift. We have all at one time or another had a vehicle on an incline and it clunked shifting out of park. Maybe the electronics are not strong enough to reliably shift out of park for vehicles at the weights of HD line, including the gas models.


Sent from my iPhone using Tapatalk
 
Last edited:

yoda

Senior Member
Joined
Jul 25, 2016
Posts
460
Reaction score
264
Ram Year
2015
Engine
6.4 Hemi
Hell, the 66 is a 68 stuffed in a 545 case. Lol


Sent from my iPhone using Tapatalk

If you go back and read what I wrote, I never said the 45RFE and 66/68RFE were the same, I said they were the same design,I was told this was ludicrous and silly.
I stand by that statement.
I think anyone who has both apart would agree with me
 

yoda

Senior Member
Joined
Jul 25, 2016
Posts
460
Reaction score
264
Ram Year
2015
Engine
6.4 Hemi
Well, sort of. It appears to be a bit of a hybrid, at least according to Allpar articles. This is from another forum post some time back:

Doing some reading on the 68 vs 66 from another Allpar article.



The 68RFE and 66RFE automatic transmissions for Ram trucks

So, in comparing to the 68RFE it appears that 3rd and 5th would be the weakest link since the underdrive/overdrive and 4c clutches are not upgraded in the 66RFE. The low range and 2c clutches (1st and 2nd) are upgraded per the article. It's unclear (to me) if the 4c and UD/OD clutch assemblies from the 68 could be retrofitted into the 66RFE, but would seem like a logical place to start during a rebuild. Per Brandon, 4th would seem to be the best gear on the dyno since no clutches are engaged. I will have to follow up with HF to see what his actual concern is.

68RFEClutchOp3_zpsgc7nysjw.jpg
68RFEClutchOp2_zps13q3vz8w.jpg

Not sure who Brandon is, but anytime the Engine is running there is a clutch applied
 

theviking

Senior Member
Supporting Member
Joined
Apr 7, 2014
Posts
1,176
Reaction score
605
Ram Year
2015
Engine
Hemi 6.4
Not sure who Brandon is, but anytime the Engine is running there is a clutch applied

I should have stated no holding clutch is applied per the chart. Basically what Brandon was stating is that this is the strongest configuration for a dyno pull. Obviously my overall understanding of an auto trans is limited. So out of curiosity, which clutches are engaged on the 66RFE when in 4th?
 

yoda

Senior Member
Joined
Jul 25, 2016
Posts
460
Reaction score
264
Ram Year
2015
Engine
6.4 Hemi
I should have stated no holding clutch is applied per the chart. Basically what Brandon was stating is that this is the strongest configuration for a dyno pull. Obviously my overall understanding of an auto trans is limited. So out of curiosity, which clutches are engaged on the 66RFE when in 4th?

OK understood. Makes sense, with no holding clutches applied, the power also goes straight through and doesn't use or put stress on any planetaries.
UD/OD, in 4th on the 66. same as the 68RFE in your chart above.
 

drittal

Senior Member
Joined
Apr 24, 2015
Posts
1,557
Reaction score
636
Location
E. Montana
Ram Year
2013
Engine
6.7
If you go back and read what I wrote, I never said the 45RFE and 66/68RFE were the same, I said they were the same design,I was told this was ludicrous and silly.

I stand by that statement.

I think anyone who has both apart would agree with me



If you go back and read what I wrote I never quoted you as saying that. I could be wrong (probably) but from what I have read about the 66 is it is basically Ram taking the gears from the 68 and making them work in the 545 case but with 68 output shaft and extension housing. Thus my short statement of the 66 is basically a 68 stuffed in a 545 case. Sure, there are differences between the them, but the short answer is what I wrote.


Sent from my iPhone using Tapatalk
 

yoda

Senior Member
Joined
Jul 25, 2016
Posts
460
Reaction score
264
Ram Year
2015
Engine
6.4 Hemi
:)
If you go back and read what I wrote I never quoted you as saying that. I could be wrong (probably) but from what I have read about the 66 is it is basically Ram taking the gears from the 68 and making them work in the 545 case but with 68 output shaft and extension housing. Thus my short statement of the 66 is basically a 68 stuffed in a 545 case. Sure, there are differences between the them, but the short answer is what I wrote.


Sent from my iPhone using Tapatalk[/QUOTE
OK, I thought you were poking fun at me and South Texas conversation. Which also would be ok.
 
Top