They've been upgraded significantly since their introduction but, sadly, not to the extent of binning them for the TR6060. They've essentially turned the T56 into a truck gearbox. Much stronger but definitely not smooth, fast or accurate.
HSV (as well as a lot of other manufacturers, including FPV and Ford) have stopped fitting T56s to their cars and are instead fitting TR6060s which, whilst still essentially a modified T56, it's a bit like the cleaner's 20 year old broom... the one that has had 15 new handles and 18 new heads - it's changed dramatically from the T56 and as such is much nicer to use. It's faster, smoother, much more accurate and able to handle significantly more torque. If Holden had turfed the tired T56 for the TR6060, they would have had a lot less gearbox problems in VEs and many happier customers who have learned to deal with the noisy and clunky gearbox that was fitted. I have had 4 replacement T56s in my ute (all within 35,000km) and am about due for number 5. Sure that's due to some underlying issue that is chewing out the synchros (no one knows) but essentially, the gearbox belongs in a truck, not in a car.
The torque rating is higher.. but I can't remember the figure off the top of my head.
So it looks like i will look at a tr6060 for my project car. I wanted to compare the VE t56 to the tr6060 to see which one would suit my project car. At the moment i have a TKO600 but am keen to pick up a highway gear. My MY10 SS ute shifts just fine and figured the tr6060 can only be better behind my twin turbo charged v12 project car (not holden).
All alloy quad cam 48v toyota v12 with variable valve timing, Twin turbocharged. 5 litre bored and stroked... unsure of final displacement as yet. Chasing 1200+ hp
Fitted to late model Toyota supra, wide bodied, 345 rear tyres, big brakes, roll caged. Final weight should be around the 1450kg mark... you sort of get the idea. Definately not what most of the forum members here would be into.
My ute is my daily, the supra will be a weekend/track toy.
Fk me! That will be a weapon. I think that is something any lover of cars could appreciate. Custom and bespoke gear is ALWAYS interesting, whether it's good or bad... But that will certainly stand out from the crowd! By track toy, I'm assuming not so much circuit racing with 1200hp! Jeepers! Depending on the torque, you'll be lucky to find a manual gearbox that will suit, as it will likely be too harsh for driveline components. TR6060 is the only aftermarket unit I can think of that would come close.
Would love to stay updated on the progress of this!