The Allison Automatic transmission module I’m talking about in the video is for a 2500 series model we’re running in all of our newer conventional buses. The older units have the 3000 series transmissions and we found that they were over and above what we needed for our fleet. Not only was it a cost saving going with the 2000 series but also a positive improvement to our preventive maintenance program.
The module I was removing has been sent to the Allison dealer for reprogramming to hold longer in third gear. Every run in the fleet is different so for this bus it’s climbing a back road for several kilometers. It upshifts too soon which drops the RPMs too low causing a lugging action and instant power loss. I’m hoping this change will improve the operation with a steady speed when climbing a grade.
There are other factors in this like tire size and differential ratio but reprogramming would be the easiest and cost effective step to take. The Allison dealer charges us their shop rate for how ever long it takes to do the adjustments on the module. Typically the transmission shifts up at around 2500 RPM and down at 1800 to 2000 RPM so when the rpm goes as low as 1500 it causes a loss of speed and power.
A new transmission module costs 1,200 bucks so a few days downtime for one bus is not a major sacrifice. I’m not sure if this will fix the problem exactly the way we want it but there’s not a lot of risk involved if this experiment does the crash and burn. I’m confident it will make a positive difference. All of our Allison transmissions are extremely reliable and part of that comes from using synthetic oil. The price is up there for us around $9.00 a liter but let me tell you the benefits of that cost.
Servicing is extended to 3 years and there has been no overheating or slipping clutches at all. Those 2 points alone prove that synthetic oil is a money saver and is paying our initial investment back. Even at three times the price we’re saving on our budget. i just ordered 500 liters of synthetic oil for our bulk tanks which totalalled close to 5,000 dollars. Servicing and replacing 20 liters of oil every three years will take a while to drain that bulk tank.
Prognostics comes with new Allison transmissions so the oil and filter life is monitored as a percentage so when the green gear with a wrench comes on at the dash it’s time to service one or the other. Clutch wear can also be monitored letting the shop know if there is a problem developing. The new technological age were experiencing is great for fleet operators helping us troubleshoot and maintain our buses taking away a lot of guess work.
