Super 10 range shift

Range change should be just as fast as a trans with the switch. Your syncro for the range change is probably getting worn. I'm guessing that is why its slow.

 

Try this
As soon as shift to lower gear, quickly mash the clutch in and relase it will shift instantly,Also you could do this as you up shift.

 

If it is a Eaton Super 10 Lightning series, if I'm not mistaken, you can pre-select it to begin with.

You are splitting every gear, correct?

I'm a little miffed as to why it is only between those 2 gears that it is laggy.

Worn synchro, but a lot of it can be air-delivery issues to the synchro as well. I'd check for kinked and pinched lines, and possibly some gunk in them. How's the air system on the truck? Nice and clean?

I'm assuming it is a clutch-less shift we are talking about. It may just be a matter of timing. When the torque load on a gear or synchro is pretty excessive as in pulling a hill, it's harder to break that torque on a shift.

I don't like seeing the words "mash and clutch" in the same sentence.

This is what I think of when I do.....



If he's lucky, all he will destroy is the clutch brake over time.

Using the clutch to break torque on a downshift is a good idea, or skipping a range split and dropping a complete gear. Half the travel of the pedal, no more. Don't "mash" it to the floor.

I'd investigate into what isn't quite right with the tranny though. Something is amiss.