How do y’all like to shift your ZF5’s?

We have a Topkick graintruck with a Tripple Nickel Cummins in it, Once get it rolling I can shift up and down without the clutch.

 

The one I used had a gas V8 in it. I don’t know what transmission, it was a 5 speed of some sort. They had two automatics and the stick. Nobody ever wanted the stick, which was fine with me. I preferred it.

 

I have a 4.10 diff and I don't see any problem starting out in 2nd. I think the 2nd gear ratio is good enough to take off when empty. Even with the close ratio tranny 1st gear is too steep.
I can take off pretty quick in 1st but this is not a car transmission either.
I would prefer a 5 speed with a true "granny gear". This is my opinion from years of hauling trailers around west Texas.

 

I'm working on a project truck that has zf 6spd, kinda anxious to see how it works. It has a true granny 1st gear like the old t-18's + overdrive.

 

Seem to recall Calvin saying floating gears in ZF was bad because only the gear face was hardened.

 

I like mine, i wish i had the -47 but its just fine . My tuck still has duAl mass flywheel, i throttle up , take it out of gear without clutch , and use slight clutch on the way in. My buddy says i drive it like its an automatic.

 

Interesting to read up on all this.

Was running my T19 around 10 years, and finally did the ZF5 swap. Always started off in 2nd, and still have been with the ZF5. It takes more feathering the clutch to get it to go without a big chug of smoke for the poor car behind me. I'm trying to get in the habit of starting to roll in 1st when a light changes, then shift, but old habits...

Outside of that, the transmission definitely makes it feel like a whole new truck, but still need to get comfortable with the big difference in 1st-2nd versus the old T19 (which I still haven't sold, maybe subconsciously hoping an overdrive pops up for sale).

 

So what's your opinion of the ZF5 vs the T19? Not differences in gear ratios, just driving in general.

 

Thats interesting that you say that. Thats my experience with the zf too, is that it feels to me like it wants to be shifted slow and deliberate, but the rpms drop so fast on the idi that catching the rpms is a total miss if you shift this way. This has been my biggest struggle learning to drive this truck. Having bad synchros too makes it that much harder since i have to be even more patient with my shifts.

So I’m kinda curious then how you guys match the rpms on upshifts? Because if you don’t shift swiftly you just can’t possibly catch the starting rpm of the next gear, at least from my experience. I find myself revving past 2600rpm so i can skip gears and upshift in a 1st to 3rd to 5th or 2nd to 4th pattern just so i can catch the rpms on their way down. Otherwise i have to do awkward rev matching on upshifts. This becomes more cumbersome on steep grades when i can’t skip gears and i just have to mash the stick and drop the clutch to catch the rpms. My idle is normal ish too at around 700rpm. So idk, i think im just missing something.

Funny enough, I can downshift rev match my truck so much better than i can upshift it most of the time. But its mostly just my truck, i have a buddy with a 6.9 zf5 with 3.55s and i can upshift and downshift that truck like butter... super annoying


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Of course the answer is to fix your transmission! But until you do...

When you upshift don't take your foot all the way off the go pedal. It sounds simple but will take a while to get used to it. You'll learn the sweet spot for each gear.

 

Hahahaha yeah yeah ik, i do really need to tear into it this summer xD

And by that do you mean like partial throttle decrease and hold - clutch in - shift - clutch out? Or like throttle off - clutch in - shift - throttle rev match - clutch out?

Thanks, thats kinda what i figured. Definitely harder than it sounds.


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You shift regularly but keep the rpms around 1000-1200 the whole time. So throttle down (but keep foot on pedal some), clutch in, shift, clutch out, and throttle up. It's easy once you get the hang of it.



Rock

 

Shifts smoother, overdrive was dearly needed, SMF with the LUK clutch makes the clutch super easy. It's a major improvement, but wish 2nd was closer to the T19 ratio.

 

I feel exactly the same way about the two. In fact, I have ever since I got to drive the two types of transmissions back to back.