FRED 5.9 ISB is Bad to the Bone

[Vickie 4369]

Just returned from a 2766 mile trip from CT to Memphis to Nashville to Concord NC at the Zmax Dragway and back to CT pulling a 28ft Racecar trailer that weighs 10K and the Coach is 24K

I know My GCVW is 30,000 but At 34K, FRED has No Problem running 75 MPH on the flats and 60 MPH up those big long hills in 4th and with the trailer brake system Set up correctly stops on a dime, and give you 9 cents Change.

Engine temps transmission temps exhaust gas temps all monitored with My Banks IQ set on economy mode Never went over 201 Degree coolant 172 Trans, or 1250 EGT.

Having if Floored at 2700 RPM for 10 minutes at 60 mph Pulling this Crazy Long Mountain on Rt 40 in TN passing all the Tractor Trailers Was the Most impressive.

Knocked down 8.5 MPG Rolling 70 mph Average.

This Set up is Long at 71 feet, and tops 34K, but handles, stops and goes like a champ.

Could not be happier with the Little Cummins that Could the 5.9 ISB.

Ted.

[fighterpilot]

Unfortunately, earlier versions than yours experienced cracked blocks and exhaust manifolds. Hope yours holds up under the high loads. But do agree, the 5.9 is one of the best small diesels ever built.

[Cruzer]

The engine isn't a problem. The ISB is a great unit. The reason your GCWR is limited is due to the Allison transmission. Alison places limits on how much weight they can move/pull and each model that is rated higher costs more money. If you exceed the GCWR your biggest worry would be over-stressing the transmission, not the engine. With that said - Allison does put a fudge factor in and rates it at continuous usage to be on the safe side.

[Vickie 4369]

Originally Posted by fighterpilot

Unfortunately, earlier versions than yours experienced cracked blocks and exhaust manifolds. Hope yours holds up under the high loads. But do agree, the 5.9 is one of the best small diesels ever built.

Yes 99-2001 Blocks and manifolds were a Problem Fixed a few myself.

There are Superduty aftermarket high flow exhaust manifolds available for those problem childs.

By 06 All of the durability problems seem to have subsided and been solved.

My only concern is injectors they are a problem to this day on these guys but I am running Powerservice Cetane booster with slick diesel at almost every fill up for insurance, more power and better fuel economy Yes It works.

The trans is awesome No heat building then no slippage happening.

Everything seems to have a 50% safety margin when ratings are set by manufacturers.

Ted.

[zeeyaarv]

Ted,
Your right. The 5.9 is the little engine that Could! Though my rig is a 2008, the ISB was--according to Cummins--the last one built in Dec 2006 at CNS - CONSOLIDATED DIESEL CO, Whitakers, NC before they began the 6.7 production. I was a little concerned about the small block so I called Cummins (always remarkable support). I asked reps opinion on the 5.9 vs the 6.7 and he said something that made pretty good sense. He said that on the long production run of the 5.9, Cummins had worked out all the production/design bugs and the last 5.9's were state of the art.
Our Coach GVWR is 27910 and GCWR is 33,000 and we travel around 28500 slick. Our toad is a Wrangler at 3800 so right around the GCWR. After researching the Banks we had the system installed, Power Pack with IQ about two years ago. To verify Banks claims, Motorhome had a test performed on a DP 5.9 --March 2012 issue. There is an actual 44% HP increase at the rear wheels and of more importance to me, an increase of 48.5% of torque at the rear wheels at 1800 rpm's. The change was remarkable. I could notably feel the change in acceleration even in the lower settings. Part of the success of upgrade is the 5.9 meshing with the Allison MH 3000. The Allison is a remarkable piece of machinery probably smarter then the person behind the wheel--at least my wheel. I did have a problem. My Turbo went out at 20k about about 10k after Banks was installed. As all failures on. DP, It's hard to qualify what caused it. Was it a built in defect? Was it the short, taxing cycles of RV driving? Or was it the increased load placed on it by the Banks. Of course Banks didn't think it was. Shop didn't think so and Cummins covered the repair under their 5 year drivetrain warranty. So who knows. The Banks is programed to add the HP and torque without putting undo stress on the turbo and Allison. When shifting, the system decreases fuel until after the shift point. The testing by Motorhome explains it all. Bottom line is we are totally happy with our Little ISB 5.9 300 and Allison 3000. We've traveled all over the country with tow and never had a problem with the grades. I'm a EGT watcher and place a lot driving decisions on this vital measurement. The Banks has built in shutoff point at 1300 degrees.
On the flats EGT maintains about 1000 with constant throttle. If you are a Banks user or checking it out, the Motorhome eval
is a really good independent report and backs up Gale Banks claims.

[Vickie 4369]

Originally Posted by zeeyaarv

Ted,
Your right. The 5.9 is the little engine that Could! Though my rig is a 2008, the ISB was--according to Cummins--the last one built in Dec 2006 at CNS - CONSOLIDATED DIESEL CO, Whitakers, NC before they began the 6.7 production. I was a little concerned about the small block so I called Cummins (always remarkable support). I asked reps opinion on the 5.9 vs the 6.7 and he said something that made pretty good sense. He said that on the long production run of the 5.9, Cummins had worked out all the production/design bugs and the last 5.9's were state of the art.
Our Coach GVWR is 27910 and GCWR is 33,000 and we travel around 28500 slick. Our toad is a Wrangler at 3800 so right around the GCWR. After researching the Banks we had the system installed, Power Pack with IQ about two years ago. To verify Banks claims, Motorhome had a test performed on a DP 5.9 --March 2012 issue. There is an actual 44% HP increase at the rear wheels and of more importance to me, an increase of 48.5% of torque at the rear wheels at 1800 rpm's. The change was remarkable. I could notably feel the change in acceleration even in the lower settings. Part of the success of upgrade is the 5.9 meshing with the Allison MH 3000. The Allison is a remarkable piece of machinery probably smarter then the person behind the wheel--at least my wheel. I did have a problem. My Turbo went out at 20k about about 10k after Banks was installed. As all failures on. DP, It's hard to qualify what caused it. Was it a built in defect? Was it the short, taxing cycles of RV driving? Or was it the increased load placed on it by the Banks. Of course Banks didn't think it was. Shop didn't think so and Cummins covered the repair under their 5 year drivetrain warranty. So who knows. The Banks is programed to add the HP and torque without putting undo stress on the turbo and Allison. When shifting, the system decreases fuel until after the shift point. The testing by Motorhome explains it all. Bottom line is we are totally happy with our Little ISB 5.9 300 and Allison 3000. We've traveled all over the country with tow and never had a problem with the grades. I'm a EGT watcher and place a lot driving decisions on this vital measurement. The Banks has built in shutoff point at 1300 degrees.
On the flats EGT maintains about 1000 with constant throttle. If you are a Banks user or checking it out, the Motorhome eval
is a really good independent report and backs up Gale Banks claims.

Great Story, What Mode do you run your Power pack IQ.

I have been just running Economy mode and saw no reason to turn it up, this thing pulls like a freight train.

Ted.

[zeeyaarv]

Originally Posted by GULFSTREAM37

Great Story, What Mode do you run your Power pack IQ.

I have been just running Economy mode and saw no reason to turn it up, this thing pulls like a freight train.

Ted.

Ted,

With toad, I normally use 2 (Economy) on the flats here on the 95 / Florida corridor depending on truck traffic. I also select the Economy push on the Allison when not in traffic and cruising. The torque is high enough for the shift into 6th a little sooner. If there are hills or driving in traffic I'll stage to 3 or 4 for quicker starts from lights. Heavy grades to 5 for short durations and never go to the 6 level. Never travel w/o toad but if I did, I'd just leave in level 3. Again, the EGT temp is always my first priority. Safe travels. Don