Question 13-15 With Aisin Trans

[bednar1320]

Do all the trucks with the Aisin trans have the HO engine, or can the Aisin trans come behind the standard 6.7?

 

[kthaxton]

An Aisin is only paired with the HO Cummins.

 

[Jared Herzog]

The Aisin may be behind a detuned Cummins in a cab and chassis i think.

 

[Joseph Donnelly]

Correct. In pickups, the HO engine only. Chassis cabs used a lower HP version.

 

[bednar1320]

Thanks guys, that's what I thought.


Looking at a 15 Big Horn 3500 DRW.........................

 

[Cummins12V98]

Thanks guys, that's what I thought.


Looking at a 15 Big Horn 3500 DRW.........................

What combined weight will you be towing? 28K or less I highly recommend the 3.42's and over that 4.10's.

 

[bednar1320]

Right at 23K, hoping to find 3.73's.........

 

[bednar1320]

Cummins12V, How do you like your 15? I currently have an 06 with a G56 and 3.42's it runs 2000RPM@70 which is OK on the level, but when I get in the hills not so much. I either have to slow down a little and use 5th, or go faster in 6th to get the RPM up.
I'm thinking the 6.7 will have more torque at a lower RPM to pull those hills.

 

[Cummins12V98]

I love my 15 it has the power I need to pull 33-35k combines West Coast.

13-17's have much more power than earlier trucks. At 23k combined you can tow in 6th with 3.42's and lock 5th on hills.

I speak from experience. My HO 11 Dually with 3.42's towed 28k easily in 5th same as 4.10's in 6th. About 1,750 at 60mph. Only negative was getting the load rolling on a grade. The AISIN with its lower starting gears allows heavy hauling with 3.42's and the best mpg running solo.

 

[bednar1320]

The 15 I drove with the Aisin was just under 1800 rpm at 70 mph, don't know what gears were in the rear, I'm assuming 3.73's, or maybe they were 3.42's?

The other thing I noticed is that the 15 rode MUCH better than my 06 and was quieter inside.

 

[Newsa]

Cummins12V, How do you like your 15? I currently have an 06 with a G56 and 3.42's it runs 2000RPM@70 which is OK on the level, but when I get in the hills not so much. I either have to slow down a little and use 5th, or go faster in 6th to get the RPM up.
I'm thinking the 6.7 will have more torque at a lower RPM to pull those hills.

I have a 2013 with G56 & 3.42's. I likewise run 2000 RPM's at 70 mph. Pulling that much weight, I would venture on hills greater than 3-4% grade you will need 5th gear. Torque on the g56 version maxes at 660 ft lbs (which you only get above 40 mph-ish). Below 40 mph, you get significant torque management. It's not significantly more than the 610 ft lbs that your 06 has.

With the Aisin, you can get up to 900 ft lbs in 4th & 5th gear. It is not recommended that you tow in 6th gear on hills in any transmission configuration (especially with 3.42's). The g56 doesn't have a good way to cool itself, except i think they went with the aluminum case for better heat transfer/cooling. The automatics have a transmission cooler, but also makes your engine run a bit hotter because the cooling system is cooling both the transmission and the engine. Never seen my temps get hotter than 212 °F even when towing on 6% grades in the summer. And i think the oil was the 212°F which is just calculated where the coolant was 208-210°F

 

[kthaxton]

Torque on the g56 version maxes at 660 ft lbs (which you only get above 40 mph-ish). Below 40 mph, you get significant torque management.

With the Aisin, you cab get up to 900 ft lbs in 4th & 5th gear.

Do you have a source for this info?
It seems like I've heard people speculate this (but have not heard the 40 mph rule before), but that's it.

In the internet forum world, I've frequently noticed one person's speculation, when repeated enough, eventually becomes fact.

 

[AEdelheit]

Cummins12V, How do you like your 15? I currently have an 06 with a G56 and 3.42's it runs 2000RPM@70 which is OK on the level, but when I get in the hills not so much. I either have to slow down a little and use 5th, or go faster in 6th to get the RPM up.
I'm thinking the 6.7 will have more torque at a lower RPM to pull those hills.

An 06 with G56 only came with 3.73 gears so unless you swapped them out then it doesnt have 3.42.

 

[Newsa]

Do you have a source for this info?
It seems like I've heard people speculate this (but have not heard the 40 mph rule before), but that's it.

In the internet forum world, I've frequently noticed one person's speculation, when repeated enough, eventually becomes fact.

I don't have a source. Bob4x4 has confirmed that g56 torque management is based on mph. I am speculating based on my real world driving experience. I do know that unloaded acceleration from 45-70 is as fast as acceleration from 20-45. And I believe that it is because torque management is released somewhere between 40-45 mph.

It is speculation. But I can be confident that with a g56, you are not getting 660 ft lbs anywhere below 40 mph. I would like to put it onba dyno to confirm or debunk my observations,

I notice that the title of this thread states 13-15 Aisin. So I see that the OP is going Aisin. I would like to contribute to his inquiry that the 2013 model has dual radiators. Not sure if they kept that for the 2014 (I think they did). But I've heard they dropped it in 2015.

 

[bednar1320]

An 06 with G56 only came with 3.73 gears so unless you swapped them out then it doesnt have 3.42.

You are correct, I did change them to 3.42's.....

 

[bednar1320]

The best I can tell with a G56 the limiting factor is the clutch. I have a Smarty Jr. I smoked the clutch towing with the middle setting, it just wouldn't hold the extra torque. Ever since then I have kept it on the lowest setting and slowest throttle response and the clutch is hanging in there. I tried an aftermarket Kevlar clutch and solid flywheel, but couldn't stand the noise from the solid flywheel.

 

[bednar1320]

The main reason that I'm looking at a new truck is to get more power to better tow my 48' LQ racecar trailer. I can make more power with the 5.9 I have now, but the clutch just won't handle it. Now after driving the 15, I was very impressed with how much better it rides and all of the amenities inside were a plus too! The 15 was a Big Horn, my 06 is a SLT.....

 

[Newsa]

I was mistaken about 900 ft lbs on the 15. I guess that reared its torquey head in 2016.

 

[bednar1320]

I was mistaken about 900 ft lbs on the 15. I guess that reared its torquey head in 2016.

Yeah, the 15 is 865 ft lbs, but that is a huge improvement over the 610 that my 06 has.......

 

[SnoKing]

I sure like my 3:42's Aisin at 24K+ combined towing. I tow in 5th at 60 and 1750 RPMs. 6th at 1750 RPMs is a 80 MPH Sunday drive. SNOKING