Downshifting, how can I learn how to do it?

One good thing to do is to figure out what are safe speeds to shift into various gears to recover but as you found out, staying calm is the most important part.

On many 10 speed road tractors there is a trick that often works. If your speedometer has the numbers that end in 5 like 25. 35. 45, 55 you can add those numbers and figure out what a safe gear is to shift into.

So if you lose a gear and you look down and you are going slower than 45, add 4+5 = 9th gear.

25 mph is 2+5 = 7th
15 mph is 1+5 = 6th

Etc.

This doesn't exactly work in low range but many of us who live in the mountains do this the first time we get in a truck. I always learn at least on the high range what speed I am at in which gear at 1500 RPM and I commit it to memory.

Not that I ever shift using the gauges but it is my fall back if I get lost and I need to recover. I do practice recoveries when in a new truck a lot and I also find that refusing to skip up and down for the first week or so really helps you build the intuition.

 

It really is just feel. I started driving rigs in the CA Bay Area so watching the tach instead of the road wold have lead to disaster. Dropping 2-4 gears at once do to traffic is normal. A slight tap on the throttle will let you slide right into gear with no grinding. I couldn't tell you what rpm and speed for a gear, I just do it by sound and feel. And it works for me.

 

On the low side and say your starting on a steep grade up shifting will take a bit longer for the rpm to come down. Opposite for down hill, you'll need to be quick on the shift or skip a gear. Hope that helps you a bit

 

If it's not going in gear from a stop let up on the clutch a bit and it should slide in

 

One thing that may make learning the timing a bit harder on an emissions truck is also realizing that your Jake will spool the turbo up and blipping the throttle will cause the rpms to increase a lot faster than you expected causing you to overshoot the sweet spot.

Also if you are downshifting with the Jake on you may be dumping RPM a lot faster than you expect on most modern trucks.

The same issue is easier to notice on upshifting on the high side vs the low side assuming you are not splitting.

Maybe try lightly rolling on the throttle while holding the shifter against the face will help out there but I learned that myself 30 years ago when you could clearly hear the turbo speed.

 

What RPM.are you trying to downshift at?

Clutching to release and floating into gear seems to be easier for many people at the start as blipping to release can make it hard to catch on the low side. I personally still can't double clutch to downshift on the low side because the window is so short up hill.

Going up hill it is often too late to downshift if you hit about 1200 RPM but if you pull out of gear at a few hundred RPM higher you will have a lot more time to get everything in place. Obviously downhill downshifting is a the opposite.

You may not agree but the trucks with problems often teach you this better.

For both uphill and traffic lights I tend to find a trucks gear that works well for a bail out too.

I drove a truck without a clutch brake for a while and it taught me to catch a low gear better than years of driving did.

If I missed catching my low gear rolling up to a stop sign I had to shut the truck off, shift onto a gear or sometimes catch that gear when the starter was cranking. It was frustrating but taught me a lot!

 

The pro’s of 13 and 18 speeds.