Truck Mount

Allison makes a host of truck automatic transmissions. A 3/4 ton pickups use a 1,000 series. 1 ton trucks typically use a 2,000 series. Single axel ~33,000 GVW trucks use a 3,000-series transmission. The bigger trucks use a 4,000 series.

We will focus on the 3,000 series. There are openings in the side of the transmission to add on a PTO. There is a port where hydraulic pressure from the transmission can be connected to the PTO clutch to control it. The transmission decides when to allow hydraulic pressure to activate the clutch in the PTO turning it on or off.

These are very well engineered products that last a very long time when taken care of appropriately. There are 3,000 and 3,500 series transmissions. The difference is that the 3500 will have a lower 1st gear. The basic design of the transmission is that it is a 6 speed. Often the 6th gear is disabled in the programming of the transmission control module, (TCM) and it is called a 5 speed. One reason for this is that the manufacture may not want the drive shaft to rotate too fast so they don’t allow a 6th gear. Once you have confirmed that you have a 3000, or 3500 Allison there are two things to consider:

1) Is there a gear in the transmission to drive a PTO?

If there is not a gear to drive the PTO it will cost about $1,500 to add one. There is a tag on the side of the transmission with a transmission serial number and model number. Write this down and call up an authorized Allison shop and they can tell you. Generally, the transmission model number will end in a P (Example 3060P) if it has the gear. Many lease trucks (Rider, Siva, or Penske) were purchased without the gear to reduce initial cost.

2) Does the software that runs the transmission allow the PTO to be “Live” all the time? Remember that we wish to have the PTO running, the mixer feeding and one foot on the brake.

The PTO is turned on and off by a switch in the cab. This signal asks the transmission to turn on the PTO. The transmission will supply hydraulic pressure activating a clutch engaging the PTO. The TCM decides when it is OK and will turn on and off the fluid to run the PTO. We have been told that after 2001 all PTOs are live, in gear, in neutral, or with brake on. We had one customer with a late 90s truck and every time the brakes were applied the PTO would stop. We had another that we scanned and saw that the software was 1999 and it worked fine, on all of the time. Again, writing down the S/N of the transmission and asking an Allison dealer a few questions can save time and money.

Other Transmission Notes

We design out over speed of the pump. Above 1,700 engine rpm the pump will be turning too fast resulting in a early failure of the pump. We have the TCM reprogrammed to turn off the pump at 1,700 rpm and restart at a lower engine speed. This is to prevent premature failure of the pump life.

There are three measures of a truck’s age; Model year, Mileage, and hours of use. The hours of use may be one of the most telling.

Hours

Most reputable truck dealer will scan the engine Control Module to read the number of hours. Just like a tractor many feel that 10,000 hours should be almost trouble free. I have looked over trucks and tractors with double that and they looked great! The use of the truck drives the average MPH (odometer reading divided by the number of hours). Cement truck will have the most hours with an average speed of 4 – 8 mph. Delivery trucks will have 15 – 25 mph. Over the road trucks will have have an average speed of ~45 mph. For the same reading on an odometer a cement truck will have 6 times or more the number of hours as an over the road truck.

Model Year

As we said in the transmission section, we were told that 2001 and later trucks the PTO is live all of the time. Another consideration is that the emission equipment used starting in 2008 may not work well as a feed truck. They create high exhaust temperatures during regeneration that could be a fire risk. Starting in 2013 most emission systems started using DEF so the fire risk is reduced.

Mileage

Truck go a lot of miles. I marvel when I read the odometer. I have read that the fluid in the transmission can last for 200,000 miles. I have talked to transmission repair people who assure me that the clutches seem to last forever. The fuel injection system has sensors that will fail as well as sundry other parts that wear out.

Let’s start with the rated weight of the truck, Gross Vehicle Weight or GVW. If the truck (non-Agriculture) is rated at over 33,000 pounds GVW then the original purchaser had to pay a government excise tax of 8% added on the truck price. If the GVW is under 24,000 then the driver does not need a Commercial Drivers License (CDL). Do not use a truck rated for less than 33,000#.

Generally, the 33,000 GVW trucks will weigh a little under 11,000#. Our biggest mixer (680) weighs in at 10,256# plus the hydraulic oil tank, oil, and the frame for our mixer on the truck. Let’s put the total at about 22,000. This leaves 11,000 pound of feed in the mixer and you are still road legal if the truck is laid out correctly. Depending on the ration mixed it is often in the 7,000-13,000 range. For farm use generally people load trucks well beyond limits. They are driven at low speeds and are not on a legal road so it is not illegal. Also as a feed truck the peak load is for a short time frame as the load constantly diminishes in feeding so the use at peak weight is a small fraction of the time it is used.

Generally, the rear end on the truck has a tag with its ratio on it. Our Demo has a ratio of about 5.5 to 1. This is OK. A 5.7 to 1 ratio would be a slight improvement. Look for a ratio numerically greater than 5.3 to 1 in the truck you wish to convert. Lower is better as you will have to use less brake in modulating feed into your bunks.

We have converted all wheel drive trucks to feed mixers. They work well. They tend to be heavier so this may affect the legal amount of feed you can carry on public roads. The biggest thing is that they are 6″ to 8″ taller. The customers that have these really like them. They are equipped to load high mixers.

The environment that a feed truck operates in is much different than it was designed for. The amount of dust in the air is great. If the truck turns its radiator fan on it will draw this dust through the radiator plugging it resulting in a truck that easily overheats. There are 4 levels of improvement/investment to the cooling system. We recommend them in this order of importance. We have worked with Rock Valley Radiator & Auto in Rock Valley Iowa on our demo and they have helped many others to make a reliable cooling system.

1) Do nothing. Leave it stock. We have some customers that chose this route. If the operator is the owner he will take care to note the way the wind is blowing when loading.  He will also blow out the radiator weekly or sooner. Because of the low horsepower requirement of our mixer, it is possible to operate the mixer without the fan turning. This will result in less debris in to plug the radiator. This is only with a clean radiator, good working fan clutch, and more attention to detail.

2) Move the air conditioning condenser away from the radiator. Typically, the air conditioning condenser is located in front of the radiator and grabs the coolest air. There is an aftermarket air conditioning condenser called a “Red Dot”. It moves the condenser to the side of the truck frame rail and has a self contained electric fan. Here is what they look like.

Beyond just giving cooler air to the radiator when the A/C is on, another benefit of this device is that it makes it easier to clean out the radiator. Due to the control of this fan the wear and tear on the air conditioner pump is reduced. Costs vary but expect to pay between $1,400 and $1,800 to have this new remote condenser installed and the coolant gas charged.

3) Change to a more open radiator. A typical radiator has fin spacing of about 0.06″. “Feed Lot” radiators have fin spacing of about 0.15″. This more open fin page allows more debris to pass though the radiator and not plug it. This also means less cooling surface to reject heat. To restore the performance of the radiator, the number of tubes in the radiators increase about 60% – 67%. The materials used in the radiators are also changed. The core is changed from most likely aluminum to brass. The tanks are changed from plastic to brass. Costs vary but expect to pay between $1,600 and $2,000 for the new improved radiator installed in your truck.

4) The last improvement is to change the fan for the radiator. Aftermarket fans can be programmed to occasionally reverse the air flow to blow out the radiator. Even with this addition the radiator will need periodic cleaning to keep it operating at peak performance. There are a lot of moving parts in this system that could wear out. Consider adding this after you better understand your needs.

We do most of the installations of our mixers on trucks. Once the PTO is installed on the transmission a load sensing pump is added behind it. The load sensing pump only pumps as much hydraulic energy as is needed. The energy is not wasted by heating up the oil when the energy is not needed to do work on the mixer. This pump requires 4 hoses on it:

1) Fluid in from the reservoir

2) High pressure fluid out

3) “Case drain” This is a drain for the fluid that sneaks past the pistons and needs to be returned to the reservoir.

4) “Load Sense” This line connects with the hydraulic valve body. It has two purposes: It will call for more fluid flow when needed, and also as a reference pressure for the proportional valves that control the speed of the reel and the elevator.

The reservoir we use is 55 gallons and has a level indicator in it and a mechanical thermometer measuring the gross temperature of the oil. We mount this between the mixer and the cab of the truck above the truck frame. This elevation above the pump gives positive pressure to the inlet fluid.

We have a proprietary valve body that controls all fluid to the mixer. The valve is controlled by electronic signals from the control box in the cab. The electrical power to the valve is controlled by electrical power to the PTO. If the PTO is not engaged there will be no electrical power to the mixer.

We can work with a variety of wheel bases. On a typical single axle 33,000# GVW truck that weighs about 11,000# we would put the mixer about 31.5″ behind the cab (about as close as it comfortably fits) leaving room for our sub frame and the hydraulic oil tank. With a 212”-wheel base both axles are loaded at 100% with about 11,000# of feed in the mixer. The total frame length required from the cab to the end of the frame is 235″ or more.

A shorter wheel base will load the rear axle higher. The same frame length will be needed. If the wheel base is longer we can move the mixer back a little to balance the load out.

Truck frames can be lengthened or shortened. The axle can be moved forward or back to make this fit. Lengthening a wheel base is more expensive than shortening it because the drive shaft has to get longer. Care must be taken to not have the drive shaft too long. Too long of a drive shaft will shake itself apart at higher road speeds. If this is predicted, then another drive shaft support bearing will have to be added. We can work through most issues to make the truck best fit your needs.

We custom design and fabricate both front and rear bumpers.

The front bumpers are about 3″ forward of the stock bumper and about 4″ wider on each side with a “Goal Post” on the outside corners to aid in driving in tight spots and protecting the headlamps. If the truck has tow hooks on it we will install windows in the bumper to access them.

The rear bumper is designed with integrated lights. They contain LED stop/tail/turn lights on each side, five LED clearance lights, incandescent backup lights and license plate illumination lights.

We add an LED flood lamp to illuminate where the feed comes out. We also have a flood lamp pointed at the left rear bumper to help avoid hitting feed bunks. These are powered the same way as the mixer. When the mixer is on the flood lamps are on.