bmac,
Yes, A B & C are the major production series of Toolcats. There are also two models (5600 [not turbo-charged] and 5600 Turbo). But all Toolcat work machines have a lot in common: all-wheel-steer and four-wheel-drive, dynamic front & rear suspension system, plus flex and axle oscillation to keep all tires on the ground for increased pushing force. /forums/images/graemlins/cool.gif
"A" series Toolcats were produced from early 2003 through the middle of 2004, and only the non-Turbo model was available. It was initially advertised with a 44hp Kubota diesel engine, but the nearly same engine later was rated and advertised at 46hp. Their axles were lighter. Bobcat recalled these early, A-series axles and they should have been replaced with the newer, heavier B-series axles at no charge, and a few other updates were made available, too. Bobcat may have even moved to the new axles before the A-series completed its production run.
"B" series Toolcats were offered in both the 5600 (non-turbocharged, 46hp) and 5600 Turbo (56hp, 22 percent more power) models and were produced from mid-2004 through September 5, 2005. Turbo is especially needed in high altitute applications. And only the Turbo models can be equiped with optional high-flow auxiliary hydraulics (26 GPM vs. 18 GPM standard, 3000 PSI). That's useful for some models of stump grinders, snowblowers, wood chippers, etc. And the Turbo models got a larger diesel fuel tank of 16 gal, vs. 10.5 gal.
And both B-series models came with several convenience upgrades from the A-series: more cab storage pockets, a new radio kit option installed in headliner, new system to raise seats for easier access to hydrostatic components, rear cargo tie-downs repositioned for easier reach, & I think a bit more sound muffling.
A few dealer-installed accessories or options are not available for A-series and/or non-Turbo models, such as the Rear PTO option, but most are available for all.
"C" series Toolcats began production on Sept. 6, 2005. Key changes are to the lift arm and tilt mechanism to make it easier to handle heavy pallet loads, plus there's more sound muffling and an improved HVAC system (I think leaking tendency reduced, but AC was already outstanding! /forums/images/graemlins/grin.gif).
I own a 2005 B-series 5600 Turbo. I'll let some recent "C" series purchasers chime in with links and details on the C-series Toolcat work machine upgrades.