I have a '61 K10 truck with a 4 speed transmission - on the floor. Engine is the 235. I have two questions - since I've had the truck, the transmission grinds when shifting into 4th. It's never changed, better or worse, but it's always been there. If I double-clutch, it does not grind. What causes this? I've had this truck 15 years with the same behavior.
It has recently started popping out of third gear when not under load - like if I'm coasting down a hill in third gear.
Should I be worried about either issue? I'm running regular 80W-90 in the tranny and transfer case. Thanks in advance!!
