Recovering a missed gear (with video explanation)

My thoughts on that is if you have to downshift on a downgrade you already messed up as you attacked it too fast. Hills are not where one loses patience and pushes the limit. In today's world there are plenty of warning signs for truckers. Downshifting should be done before the descent. Why? If a driver misses a gear it is very easy for a driver to gain speed past the operating rpm limits of the truck. You are then considered having lost control of the vehicle. If one is unfamiliar will a downgrade he should attack it slower then the posted caution sign. One can always upshift much safer than downshift. Truck drivers should be familiar with grade percentages and gear/rpm ratio limits. If you are braking down to the 1000 rpm range on a hill you have heated your brakes up way more than necessary. Compound that with a missed gear and the situation can become critical.

It used to be a rule of thumb a driver would descend a hill one gear lower than he climbed it. Today's trucks are more aerodynamic and have less rolling resistance so if one is not familiar with a hill one should start descending two gears lower. Mountains like Monteagle are not a perfect triangle. One side is steeper than the other. That's where a driver should take warning to the caution signs and that should be your max speed until one is familiar with a mountain.

Disengage governor? Do you mean engine brake? A governor restricts the speed of a vehicle by the ECM controlling the fuel flow. An engine brake controls cylinder compression to counter the spring effect of a piston/crankshaft rotation.

 

Spot on, Condo! Very true & important info that needed to be addressed in this thread.

Don't fall into the "thinking" that if you get into trouble on a downgrade, you can simply slow to 800 RPM and downshift.
Those brakes may not be very effective at the end of any slowdown to sub-1000 rpms.
Take that "thinking" and apply it where it belongs... PRIOR to the downgrade.

An important note on the video... I only watched about half of it, but I saw a major concern (a big No-No).
Starting about the 4 minute mark the driver/demonstrator shows what to do if you forget to flip the range selector before a shift that changes ranges.
He demonstrates a missed gear by not having flipped his range selector.
BUT,, he then shows (multiple times, and each time) thruout the video that he flips the range selector while in the NEUTRAL gate.
There is no quicker way to damage a transmission than by doing this. Never flip your range selector while in neutral... period.
This will cause certain damage to your transmission's range synchronizers. It's also in every Roadranger/Eaton service manual.

 

I "tap out" when floating gears and I'm hard against the jake brake on a descent or hard on the accelerator on an ascent. It just makes it easier to get out of gear, instead of trying to pull it out when the transmission is under load one way or the other, then it can stick in the gear and you lose rhythm on the shift.

 

The placement of the camera was very good. you get a good view of the movements. I liked this video so much i checked out his other videos . Especially one called Wrong Clutching. In it he talks about seat position and heal and toe clutching.

 

Thanks for the useful responses

 

Just as a quick FYI for any students in driving school that are preparing to do their CDL skills test with the DMV. Never float gears while doing a DMV test. Always double clutch both upshifts and downshifts in front of a DOT tester. Once you have your CDL and your own truck then float gears to your hearts content.

And personally I have to agree with him though. I always liked the clutch out, float back in downshift. In particular, this is best used when braking in particular since you can't really float out of gear while braking (unless you idle float it out).

 

so it looks like, when he's bringing it from 4th to 5th and misses 5th (and ends up in neutral), while in neutral he revs up the engine slowly while floating the gear back in 4th ? is that correct?

 

If you are up shifting from 4th to 5th and miss 5th gear, you're going to either try to recover into 5th gear or maybe even 6th gear because you still would pick up some forward momentum while in neutral. The only exception would be on an upgrade, where gravity will naturally slow the vehicle down while in neutral. In that case you might have to recover to 4th. Everything depends on your road speed and how each gears Rpms match up.