my vehicle was climbing a hill in 3rd then struggled and popped out of gear into a higher gear. It then made some clunky shift changes for a few miles. I believe it's an Allison 4spd w electronic OD. My question is - is this a sign of impending failure or possible tranny service. It has 32,00 highway miles on it. Thx for your advice

 

If you have an F600, this belongs in either the Large Truck forum or the Superduty forum.

I am moving this to the Large Truck forum.

And WELCOME to FTE!