Help downshifting and any tips

Smooth is quicker.
Slow is fast.

Need a lot more info to match speeds/rpm etc. Motor, trans, Rear end ratio?

 

Agree with b-g. For downshifting, my trainer taught me to double-clutch out of the current gear around 1100, rev 100-200 rpm past where the next lower gear would put the engine speed (usually 300-400 rpm between gears on most trucks - ex. 1100 in 8th would be 1400-1500 in 7th, meaning rev to 1600-1700 while downshifting), and double-clutch in as the rpm fell back. This helps to catch the right rpm in getting it in. A slight pause as you go across neutral helps a lot as well.

It's a rhythm... (bump-bump) on the clutch as you bring the shifter out of the current gear, slight pause in neutral as you rev the engine a few hundred rpm (a dab on the throttle will do ya), then another (bump-bump) on the clutch as you catch the rpm going to the lower gear. Think of each gear in the transmission as a room. Then think of the clutch as a door you have to open and close every time you enter or exit by doing a double-tap of light pressure (not fully depressed, only do this at a full stop). It will come to you.

When you say "skip gears", I don't recommend that for downshifting, IF it can even be done. Seems to me you'd have to rev to almost 2k to do that. Skipping on upshifts is no problem, just requires a pronounced delay before going to the intended gear, but can cause lugging, which isn't a good thing.

Once you get more experienced and can float them, you'll be able to do it all day no problem. When you get to where you can float them, you can use a light tap of the throttle to ease it out of the current gear, giving a slight pause as you go across neutral, simultaneously giving the throttle a jab to the right rpm. The pause helps upshifting or downshifting for smoothness, which is what I think b-g means by "smooth is quicker, slow is fast".

Also, keep in mind that a truck with a misadjusted clutch/clutch-brake will prove difficult at best. The engine and transmission can and will sometimes fight this process under engine braking, best to turn off engine brake between gears when downshifting until you get the hang of it. Cascadias are good for this, as they have the engine brake switch on the steering wheel.

Didn't catch the 8-speed part until just now. I trained on the E-F 5L/5H 10-speed, but had a little time with a 9-speed as well. I had posted some info earlier on the assumption that 8-speeds were basically a 5L/5H 10-speed with the 1/6 position eliminated. However, from looking at the shift pattern I found, there is one glaring difference -- you're making a W with the shifter, rather than a standard H. Not what I'm used to. Driven a Super 10 before, but not these. Therefore, I've retracted what I posted in specific regard to the 10-speed in the interest of not confusing you. Hopefully what I've passed along in respect to getting the rhythm down will help your shifting, however. That does not change with the transmission gear arrangement. The action required to shift is still the same regardless of pattern.

 

Im guessing your in a 8LL which is same as a 9 with deep reduction on the low side. Keep the jake off down shifting it will give you some more time. Roughly 500 rpm between gears. To skip a gear bring it down to a 1000 and it should fall right in around 1800.

Everyones different but i learned to float easier than double clutch. I still float better than dbl clutch. A lot of the time i use the clutch getting it out of gear then float it in. Easier than a 10 to learn on. Nice slow shifter especially paired with the isx. I leave the Jake on cuz it drops off so slow. You'll get the hang of it and yes slower is faster.

I'll take a 8ll or 9 anyday over a 10. I hate hate 10s

 

What is the biggest difference between an 8/9 speed compared to a ten? Thanks in advance.

 

A 9/8ll is regular H with lo being on left and back. There is no over and down from low to high range. On a ten 5th/10th is over to the right and back and 1/6th is to the left and back. Not your regular H.

And a 9 over has a has a lower ratio in the low hole than 1st in a 10 direct which most fleets have. 13 and 18 same shift pattern as 8ll or 9. You have the ability to split the high side on a 13 and both on a 18

 

You have to time it according to "how fast rpms Fall Off". You may not be raising rpms enough,or raising them too much.It shouldnt be a "Panicky moment". Oh No! It might not go in gear!. Take it easy,dont try to do a Power Shift,like youre playing Pole Position.If its a "Hashed out Tranny". ,,a n ever slight pause,going across neutral may help.Or you can float.JMA

 

If you are using your brakes around town or on off ramps, you do not need to worry about overheating them. If you are on a long downhill or a really steep long downhill, then you should worry about overheating your brakes.

 

is the 8LL transmission only typically found on dump trucks? both dump trucks i have driven were both 8LL with every other manual truck being the 10 speed arrangement. if im not mistaken the 8LL is a construction duty transmission designed for lugging ability on un-even ground and starting on a steep grade like a dump truck often does when you are off-road.

 

Correct. Oilfield uses them a lot also. For that type of work either 8ll or 18 or your cutting your self short