I've driven a half dozen auto's and own a manual.
Autos will can run up to 2500-2800 rpm, shift and not break a
sweat. I shift around 1700, but if I really want to go 2200 feels
and sounds like Red Line. I don't have 4.10 gears. I'm doing 70
@ 2000 in 6th.

I'm not sure if this is in my head or if the minute difference in gearing
makes that big of a difference. --or is something wrong??

Anyone else know what I'm talking about?

 

Yeah... I get it. All that metal slinging around sounds more dramatic than on just about any other consumer vehicle. That motor was initially developed for medium trucks, and we're used to engines for cars/light trucks. Redline is about 3200, and I've driven hard across Montana with cruise set at 2500-2600 RPM. People who tow see those RPMs on grades all the time. The engine will take it on something as minor as a shift.

A chipped truck can make the engine noise almost unbearable, depending on the tuner. Are you chipped?

 

OP...i hear ya bud. Friends' rig, shifts smooth, and like you said, at those numbers. Mine (zf6), is LUCKY to see them high rpms, without a load behind ur. Shifting around the 15-1800rpm mark too. I dont think i EVER seen 3k on my truck, and thats pushing any/all gears, lol

 

Do french fries let the tach reach 3000?

I know better... just a ribbing.

 

I often wonder about the same thing. I used to be afraid to get mine above 2200, but after riding in an auto I will run 2400 up some of the mountain passes when loaded with 4500# truck camper and pulling my boat in 5th and that keeps me around 58 to 60. I don't think people can relate unless they have a manual or have spent some time driving one. Those numbers are with 35's and 3.73's.

 

Seems to me 3rd and 4th gear in the 4R100 are the same/close to the ZF6 in 5th and 6th.

I shift 1800-2000 as well, towing I do shift around 2500 since the "boost" doesn't really come on until after 2k.

I have been to 3000 RPM in 5th a few times on the highway when 6th didn't have the oomph to pass or pull a steep grade.

I did think it was sort of funny when a "red lined" 5th gear in the passing lane once and had to go the 6th....

 

Good to know -- I haven't gone crazy yet.
I would say that 2200-2500 (unloaded) is really stretching out the legs.

2600-3000 (Unloaded) -- Somethings about to come unglued.

I couldn't find anything on the subject with searches -- Probably just not
many manny's out there.

 

The automatic transmissions have a torque converter that multiplies torque but also lose RPM to slippage until it locks up so that is why it feels different than a manual trans truck. Under most conditions, the TC is not locked until after the trans has shifted into 3rd gear so the 1-2 and 2-3 shift is softened by the TC.

 

A lot of it's mental. And a lot of that has to do with being able to shift at 1700 - 1800 rpms and still have comfortable power. Because we've got more power at the lower rpms (not really but we're able to lean into the skinny pedal at those rpm's and use the torque available there while the autos just downshift if you lean into them in that range.

Our trucks handle 2400 rpms and more just fine, but without a tuner you're dropping off the torque curve so it feels like you're running the engine into a wall by not shifting.

 

haha...nope, but does make me drive faster cuz its smell gets me hungry

My truck loved towing in them 24-2600rpm range. Heck, just let ur twist all the way there. I thought OP was concerned on how his/zf6 trucks acted differently in just normal driving then the autos...