Here's an Allison Automatic shift story for you;;;
Picked up a new to me m923 at Ft Lewis today. Started and ran great, so after checking things over, headed for home. I was shifting up through the gears manually instead of using 1-5. It seems to like shifting the best around 1800 or so.
So after the first fuel stop I just dropped it into 1-5 and let it shift itself up to freeway speed. After it went through the gears, I got this terrible dry bearing wailing sound, kind of like a dry driveline carrier bearing only worse.
I pulled over at the first safe spot and gave everything a good check over. Suspicious that letting it pick its own shift points for some weird reason caused the problem, I went back to upshifting manually. It shifted perfectly and ran out nice all the way home.
So! Is this just my truck, or have others had a similar experience? Was I driving it wrong? I noticed it didn't shift just how I thought it should at other times too, so I will be checking the shift points and perhaps taking it to an Allison dealer.
What say you all?
Thanks!
BS
Edit: BTW, the truck only has 3000 miles on it since a Red River overhaul.