Originally Posted By: demarpaint
I have the urge at least for now, to buy a new 2012 Jeep Wrangler. 6/6/11 they start taking orders, but I'll be waiting. So far I'm liking the Pentastar engine, and I found out today they will be going with the W5A580 5 speed AT. How are these transmissions?
TIA
The W5A580 is the transmission that's been in use in V8-powered Magnums, 300s, Challengers, and Chargers for a number of years. Its pretty near bulletproof, and I would think even moreso in a v6 application. It was originally a Benz design, somewhat streamlined and simplified by Chrysler and now produced at their transmission plant in Indiana. The other transmission I thought they might use for the Wrangler would be the Chrysler-designed 545RFE, but that is a bigger, heavier transmission currently used in fullsize trucks and the (previous generation) Grand Cherokee. They're both capable of dealing with huge torque inputs, but the 580 is more of a "car" transmission and the 545RFE more of a "truck" transmission. And if you look at the gear ratios, the 580 is probably better suited to a somewhat peaky engine with less off-idle torque than the 3.8, like the pentastar (see next comments below). The 580 (and maybe the 545RFE also) will probably be replaced by the Chrysler/ZF collaborative 8-speed automatic that's in the works.
At any rate, the 580 is a rock. Don't worry about it. In fact I wouldn't worry about any currently-built Chrysler transmission- the days of the 41TE in minivans are gone.
If I have any questions about the 2012 Wrangler, its not about the transmission so much as the applicability of the Pentastar v6 for an offroad vehicle. The 3.8 gets a lot of complaints for lack of horsepower, slow acceleration, etc on-road, but the real reason the 3.8 was chosen for the Wrangler in the first place was its torque curve. Of all Chrysler's engines, it was the most similar in torque curve to the old 4.0 straight-six it replaced. One of the most critical characteristics for offroading is off-idle torque. Both the old 4.0 and the equally old 3.8 do a great job off-road, with their ability to idle over obstacles smoothly and with great control. They hit almost their peak torque within a few hundred RPM of idle speed, and maintain it over the whole range. The Pentastar, at least in the Grand Cherokee, looks like it has a much peakier torque curve and really REALLY needs more than 5 gears in the gearbox to work effectively at very low speeds. Whether Chrysler will address that with a different cam profile or different engine management software (its already got VVT after all) for the Wrangler will, in my opinion, be a very critical component of whether the Wrangler stays a capable- maybe the MOST capable- off-the-showroom-floor offroader you can buy, or just another poser SUV that looks more capable than it really is. I don't mind so much that they replaced the Cherokee with a more street-friendly vehicle (Liberty), but if they take ONE ounce of offroad capability away from the Wrangler, a lot of Jeep devotees will be very angry. For example, it really needs those solid axles, and if you don't like the way they work on-road, don't buy one.
