Dodge Nitro Forum banner

NAG1 Transmission: Description and Operation

31330 Views 25 Replies 15 Participants Last post by  Scar0
1 - 20 of 26 Posts
Cool Info, Thanks for the post. Do you know how long this tranny has been around? And do you know if it is true that it is used on the SRT-8's (Charger, 300, Magnum)?
Cool Info, Thanks for the post. Do you know how long this tranny has been around? And do you know if it is true that it is used on the SRT-8's (Charger, 300, Magnum)?
This transmission is infact used in the LX platform cars (Charger, 300, Magnum). It was introduced in 2003-2004. It is also used in the Crossfire, Grand Cherokees, also the Liberty with the 3.7L and also the short-lived diesel engine. It is also found in a Dodge Sprinter. This transmission is designed by Mercedes-Benz.
Being from a family of Grand Caravan owners, needless to say I am well aware of the long list of transmission/CPU problems Dodge/Crystler has had in the past years...

I was told in the past that part of the reason Dodge/Crystler had soo many transmission problems was because they were using car transmissions in their Van's and small SUV's instead of more heavy Duty Truck transmissions.


So My question is, is this Nag1 transmission a "Truck" transmission?

I am considering the R/T and plan on using it for towing. I don't want to put 3 transmissions in it by the time I reach 100,000 miles....

Also, how does the Nag1 Transmission differ from the 42RLE transmission? I test drove both an SLT, and an R/T The SLT actually felt a little more responsive, But I wasn't sure if that was due to being 1 less gear, a different gear ratio, or transmission design in general?

Thanks,

-TheChad
See less See more
Hey Nitrotech.

I've heard from a couple of different sources about how this is a "smart" transmission that "learns" your driving habits as well as tries to maximize both fuel efficiency and performance. Can you explain that to the group?
Hey Nitrotech.

I've heard from a couple of different sources about how this is a "smart" transmission that "learns" your driving habits as well as tries to maximize both fuel efficiency and performance. Can you explain that to the group?

It has all the info right in the owners manual on page 250:

5 speed trans "the transmission electronics are self calibrating, therefore the first few shifts may be somewhat abrupt, this is normal and precision shifts will develop withtin a few hundred miles....................its all in the manual

Doesnt say how it does it but this tells about the trans (their is more read it if you want to get the full version)

This also explains the "Hard" shifting complaint that some people have reported in the R/T
It has all the info right in the owners manual on page 250:

5 speed trans "the transmission electronics are self calibrating, therefore the first few shifts may be somewhat abrupt, this is normal and precision shifts will develop withtin a few hundred miles....................its all in the manual

Doesnt say how it does it but this tells about the trans (their is more read it if you want to get the full version)

This also explains the "Hard" shifting complaint that some people have reported in the R/T
So my dealer told me today, that it takes 10-15000 K for it to smooth out, doesn't seem right to me....
Being from a family of Grand Caravan owners, needless to say I am well aware of the long list of transmission/CPU problems Dodge/Crystler has had in the past years...

I was told in the past that part of the reason Dodge/Crystler had soo many transmission problems was because they were using car transmissions in their Van's and small SUV's instead of more heavy Duty Truck transmissions.


So My question is, is this Nag1 transmission a "Truck" transmission?

I am considering the R/T and plan on using it for towing. I don't want to put 3 transmissions in it by the time I reach 100,000 miles....

Also, how does the Nag1 Transmission differ from the 42RLE transmission? I test drove both an SLT, and an R/T The SLT actually felt a little more responsive, But I wasn't sure if that was due to being 1 less gear, a different gear ratio, or transmission design in general?

Thanks,

-TheChad
I wouldn't call the NAG1 a truck transmission. The NAG1 is found in many Chrysler products. Jeep Liberty's, Grand Cherokee's, SRT8, Ram Truck, Sprinters, and so on. The difference is the input torque ability of the transmission. Being capable to be mated to a 6.1L HEMI it can handle anything the 4.0L in the Nitro can dish out.
So my dealer told me today, that it takes 10-15000 K for it to smooth out, doesn't seem right to me....
Never heard that one before. The adaptive programming for these transmissions relearns in less then 1000km.
Stall speed is related to the torque converter.

Stall is roughly the speed in RPM where the torque output nearly matches the input. In theory the engine will stall with your foot on the brake if you rev the engine to this speed. This is does not always happen in practice so don't try it to test stall speed.

Basically high stall speed means more slippage at low RPM but more torque multiplication. High stall speed converters are used on drag race cars or hot street cars that are tuned for high power at higher RPM.
I haven't seen a published stall speed for the NAG1 torque converter.
Stall speed is related to the torque converter.

Stall is roughly the speed in RPM where the torque output nearly matches the input. In theory the engine will stall with your foot on the brake if you rev the engine to this speed. This is does not always happen in practice so don't try it to test stall speed.

Basically high stall speed means more slippage at low RPM but more torque multiplication. High stall speed converters are used on drag race cars or hot street cars that are tuned for high power at higher RPM.
You sir, are a wealth of information, I was asking what the stall speed was of the NAG1 transmission, in hopes of yes you guessed it, a high stall torque converter. Regardless of your race car input, I had a 1800 stall speed TQ in my last car and loved it, I also had it paired with a LSD from the Toyota Supra.

I haven't seen a published stall speed for the NAG1 torque converter.
Thank you. I am curious what it is. I'm sure some performance place has made a high stall if its in the charger/magnum.

I must say regarding the 10,000 mile comment, my Nitro has been getting smoother, I took it to the dealer and maybe they reset a code without telling me when they checked it, but it definitely has been better lately, I'm around 7100 miles.
WhiteNitro,

Sorry, I missunderstood your question. I thought you were asking for the definition of "Stall".

I did not realize that you were asking for tha value of the stall speed.

Ken
Has anyone had a problem like this? When I am going to pass a vehicle and go into "passing gear", right about the time it starts to shift up the transmission acts like it goes into neutral. I can pull over and almost come to a complete stop and it will engage again. The engine light will come on then go off after three or four starts. The dealer says it does not store a code. This is on a 2007 R/T built in February.
Is the NAG1 used on my '08 3.7l SXT? it says 4 speed trans but there's only 3 postions on the shift selector? When I'm on the freeway and set the cruise, it seems like it could use one more gear to lower the RPM and get better gas milage. Thanks, Douglas
Douglas, you have the four speed (42RLE). This is the five speed. The fourth gear you notice is overdrive. It's for lowering the RPMs for better mileage when cruising, just as you said.
Thanks Tyler, how come there's only three positions on the gear selector? And when cruise is set at 73MPH, it seems to me like the RPM's are higher than they should be? I was thinking RPM should drop down to about 1000-1200? Maybe it's because of the 3.73 rear end? Thanks, Douglas
Douglas, the gear selector has a D position right? The selector only dictates what the top gear is that the vehicle can shift into. When set to 3, your vehicle can use 1, 2 or 3. When in drive, you have all 4 gears available.

And yes, the 3.73 rear is part of the high RPMs, the other being the gearing in the transmission itself. I have the R/T with the 3.55 rear end, but it's still pushing 2500 RPMs at about 73 mph.
I have NAG1 on my RT, how ever my car was pre-owned with 7000km's on odo, it was women owned and my driving habits are bit different ..

So, what is easyest way to reset transmission and teach how this thing is supposed to drive again :)
1 - 20 of 26 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top