After near 1000 miles on the new 2011 the revamped Allison is proving to be somewhat of a mystery to me. The transmission shifts are more seamless than on the 06 as advertized and power transmission; I have just a gut feel, is just less power consumptive. Some early dyno results would reinforce that unless GM has underated the new LML powerplant.
What has me quite baffled is the fact that the new transmission can run so cool. Putting 465 unloaded miles on the truck for initial break in, many of which were against a substantial adverse wind and up-hill conditions, the hottest transmission temp reading I saw was 133 degrees! My first though was that the DIC was wrong, but after doing a fluid level check I found that the level was only a little over the high end of the cold level range. I also felt of the pumpkin and was amazed that it was only fairly warm, I'd guess in the 95 degree range.
Now yesterday I hooked up to the fifth wheel, which I'd say I got down the the 13,000 lb range after unloading some stuff and towed for 200 miles, some of which at the end of the run were at 70 mph and against an adverse wind of about 25 mph, and earlier were up some pretty good grades but less than 2 miles in length; the highest tempreture that I saw was 149 degrees, which would seem pretty impossible.
My only explaination would be that the thing is so strong and can lock down the packs so tight that there is just no slippage that can build up heat. My question is, how can you ever do a hot check on this new transmission?
Curious to see if others are experiencing the same thing.