Re: Allison Transmission Questions
rwoody - 12/4/2008 9:38 PM
ok
this is not a regear
i have a 30,000 lb mtr home and will install the 8.3 and 3060 in the bus
i wanted the other 2 gears turned on the trans TCM/ECM
the shop wanted my vin number off the truck that it came out of
i had that ---then they told me that the truck would go to fast with the other gears --that it was blocked because of it being a fire truck and that was that
I and installing in a bus with 5.29 gear and need the other overdrives
the fire truck was 4.88 and didnt need them or they did not want them--they might have thought a drive would run the water pump too fast if they had overdrive(had aux tran in drive line to run pump)
it has a heavy spec tc as it was gvw at 39000....i just dont know who or how to get the gears turned on in this calibaration
should i find a mtr home with this calibration and give them that info to get it done?
thanks so much!!!!!!!!
also its a wtec 2 ------what is the differance if i change the wiring and ecm to the wtec 3?????
what does the newer system give me..there is some parts avil as my buddy has this other setup to install in a truck.
is the iscannsomething that can be done with the powerplant sitting on a trailer?
Okay.
1. If the installation of the 8.3 and the MD is going into a vehicle that did not have an MD before, that is what is called a regear.
2. If the ECU you had came out of a fire truck, DO NOT USE IT without a completely new program being loaded into it for a motorhome. The emergency vehicle calibrations have some of the safety features turned off to enable the vehicle to move in an emergency.
3. Most of the time, when the overdrives are turned off in the transmission calibration, it is to prevent the driveline from being spun too fast. BAD things happen after a driveline passes its critical speed.
4. iSCAAN is a computer program Allison authorized service outlets have access to, to properly choose transmission, torque converter, axle, tire size, engine power etc. so the assembled vehicle will perform properly.
5. The only way to make sure this vehicle will properly perform once you're done, is to do that iSCAAN.
6. The only way you should even think about turning on those top two gears is if you can install in a properly engineered driveline. That means your shaft lengths, shaft size, angularity, driveline maximum speed (top engine rpm divided by trans top gear ratio) and phasing must be within proper tolerances. Allison also has available what's called installation design calculation software. That software contains a program which will do a driveline analysis. Dana also has a similar program called Dana Expert.
7. WTEC III also involves changes to the transmission.
This is a big job, it's not like taking out a 265 small block and putting in a 283. It can be done, just do hour homework before getting too far along.
