Figured it was aboiut time I started a real thread for the Transmission swap on the RedByrd.
first, for the Newbies on the site: This is redByrd The Bus.
The Project:
the Allison AT545 transmission in the bus was run since i got the bus (and before), with a bad modulator.. a bad modulator on an Electronic AT545 will ruin the transmission over time, esp if you drive it on the highway alot or are towing, heavy bus, etc..
the Transmission started not wanting to downshift to first gear, it wanted to buck and shudder on the 2-3 shift.. sometimes would slide itself into 4th.. (this AFTER replacing the bad modulator)..
here is a Long and boring video of me rambling and pointing out how the bad transmission is acting like a bad transmission.
how to fix it?
well i couldve pulled the AT545, and sent it to a shop to be rebuilt, got a used AT545... or we could UPGRADE! I chose the path to Upgrade.
so the project is an allison AT545 to Allison 1000 series Swap.
whats the upgrade other than a higher number?
The allison 1000 is a stout 6 speed Overdrive automatic vs the 4 speed Non-Overdrive AT545.
some notable improvements of the 1000 over the AT545.
1. 2 overdrive gears.. I will have a .71 and a .60 Overdrive if I choose to.
2. Lockup Torque Converter.. the 1000 will Lock out the Torque converter fluid drive, this allows the engine's power to be sent to the wheels, not eaten up in heat like the AT545. (other allisons such as MT643, 3060,2000, etc also do this).
3. Electronic control. Allows me to reprogram how the transmission operates via computer programming as opposed to removing and reinstalling the pan, drilling valve body etc to achieve the characteristics I want.
4. Fringe benefit - Park. the new trans has the 'P' position.. with a park pawl capable of holding 30,000 lbs on a 15% grade.
5. Much Heavier duty - its visible when looking at both. I had mine built by a transmission shop that builds these for guys who really turn up their engines, while my engine is stock.. if I do decide to turn up the Smoke, I have the trans to handle it.. (mine is built for 500 HP capable).
Why did i choose the 1000 over other transmissions?
the AT545 to 1000 swap is a straightforward swap out, the 1000 could be built with the SAE3 bellhousing bolt pattern, the tailshaft installed could be set up to handle the drum parking brake that the AT545 had. the shift pattern is the same (with the addition of P if I choose to use it), the overall length once installed is only 3/4" Longer than the AT545. I may not have to shorten the driveshaft.
here we go!, I'll be creating posts to catch up on the progress!.
-Christopher