New L9 in an M2

[hookliftpete]

Anyone know anything about these new cummins L9 engines? Company that I drive for got a tri axle log truck Freightliner M2 with one of these in it. Crappy allison 6sp auto too...

Poor throttle response, even when the truck is empty...it's around 40k empty...

Are the new engines able to be accessed with insite 7x?

[tree98]

You sure it's an L9? That's a really small engine to have in a log truck. It's a 9 liter engine in the neighborhood of 350 h.p.

No 7.6.2 you need 8.3

[hookliftpete]

Yep, L9....should have taken a picture....hardly bigger than the isc in my pete...

[hhow55]

I have an l9 370hp in a quad axle dump truck, with a alllison auto 6 sp and i love it. Course i have 5.29 rears. It usually grossed out at 64000 lbs. And yes it go's faster than 40mph.

[tree98]

I have an L9 in a western star 4700 crane truck. It's 350 hp with an 8LL. Truck weighs around 58,000 and it's no power house by any means. My log trucks have 15 liter engines (870,X15) because they usually gross in the 80,000 neighborhood. An L9 wouldn't be a very good choice in my opinion.

[hookliftpete]

I wish I had an 8LL, wouldn’t be too bad then. The shift points are crap, it lugs down to 1200 before it’ll downshift...I’m sure the rears are tall too..

[tree98]

Yeah mine is the same way, they spec all these new trucks with really tall rears. Makes it hard to go slow enough offroad sometimes without slipping the hell out of the clutch, even in low low . Shift points suck, you have to wind it all the way out and shift fast before the rpm's drop like a rock and seem to be amplified by a ton of lag time in the programming for the throttle response. Not a very impressive setup for offroad vocational trucks.

[Luckyjayb]

(02-22-2020 )tree98 Wrote:  Yeah mine is the same way, they spec all these new trucks with really tall rears. Makes it hard to go slow enough offroad sometimes without slipping the hell out of the clutch, even in low low . Shift points suck, you have to wind it all the way out and shift fast before the rpm's drop like a rock and seem to be amplified by a ton of lag time in the programming for the throttle response. Not a very impressive setup for offroad vocational trucks.

I have one in a 16 wrecker and I adjusted the Allison parameters to shift at the higher rpm’s. I’ve had truck over 16 tons behind be and walk the dog with it. If you need help on the Allison parameters, pm me

[Luckyjayb]

I’ve also had mine tuned by one of our member and it woke it up. I have the Allison 3000rds six speed auto in mine. After I adjusted the parameters on the Allison software, it shifts under a load between 1950-2100rpms, same if I stomp it. If I just put put around, it shifts around 1600rpms. I also enabled the secondary mode feature and when I enable that, it shifts only between 1950-2100 rpm’s at all times. I can have a tractor hooked to the back of that wrecker and be overloaded and still pull it between 80-90mph all day