why does the truck lift up

[Bondo]

Re: why does the truck lift up

[QUOTE Frankly, If you see a semi truck doing this, they're probably using far to much throttle and not shifting when they should.

Apparently,you've never driven an 18 wheeler.[/QUOTE]

Ayuh,... Especially not a Heavily Loaded 1....

 

[justchange]

Re: why does the truck lift up

[QUOTE Frankly, If you see a semi truck doing this, they're probably using far to much throttle and not shifting when they should.

Apparently,you've never driven an 18 wheeler.[/QUOTE]


Guess, then you don't know HOW to drive one. Been drivin' one far too long.


If you shift at low rpm[1200-1400] and let the engine work-[as you should] you don't have or have very little lift.

 

[justchange]

Re: why does the truck lift up

Just to confuse the issue....... wait until you drive a High Performance front wheel drive and it torque steers into another lane!!

Fun, ain't it?

 

[wajajaja02]

Re: why does the truck lift up

try adjusting the trim tabs er tail gate

 

[justchange]

Re: why does the truck lift up

try adjusting the trim tabs

 

[dolluper]

Re: why does the truck lift up

BAD motor mounts....esp in rice burnners

 

[Summer Fun]

Re: why does the truck lift up

If you shift at low rpm[1200-1400] and let the engine work-[as you should] you don't have or have very

Why are you lugging that motor so much ??. I've been driving trucks for over 33yrs and never heard of that kind of thinking . I'm glad you don't drive my truck.

Guess, then you don't know HOW to drive one. Been drivin' one far too long.

Yes, you have and can't remember how to treat a diesel motor.

 

[QC]

Re: why does the truck lift up

Why are you lugging that motor so much ??. I've been driving trucks for over 33yrs and never heard of that kind of thinking . I'm glad you don't drive my truck. Yes, you have and can't remember how to treat a diesel motor.

Uh . . . well I have been teaching Caterpillar truck engine operators for 30 years and we have been trying to get them to lug them down to 1200 before downshifting almost that entire time. Today we are saying 1100 . . . With an 1800 RPM rating and a nine speed how do you do any different We even say you can cruise there although we like 1400 RPM a little better for flexibility. I guarantee anytime you have an engine dynoed at a CAT shop they give her all she's got all the way down to 1200 and lower, even on a brand new engine or fresh rebuild You sir are driving like we taught them 40 years ago . . .

 

[Summer Fun]

Re: why does the truck lift up

well I have been teaching Caterpillar truck engine operators for 30 years

Well Macks with a 18 speed love it from 1600 to 2150 , . Maybe you were taught wrong in the real life of dirving trucks

 

[dlngr]

Re: why does the truck lift up

Apparently,you've never driven an 18 wheeler.

Guess, then you don't know HOW to drive one. Been drivin' one far too long.


If you shift at low rpm[1200-1400] and let the engine work-[as you should] you don't have or have very little lift.[/QUOTE]
I drive a Mack with 400 hp and a 13 speed-typically pulling 73,000 to 80,000 lbs If I shifted from 1st to 2nd at 12 to 1400 rpm,the truck would be at a dead stop before I dropped it into the next gear.Usually shift up at 1700 rpm -1800 if I 'm on a incline. With a 400 rpm spread between gears,shifting at 1200 puts me at 800 rpm in the next gear-I'd be going nowhere real quick.
Mack power band is 1150-1800 rpm that means a minimum shift rpm of 1550,but that's not enough speed on even a slight hill.

 

[HappierWet]

Re: why does the truck lift up

COOL, an intelligent question about physics turned into a bash fest about driving techniques. NOW we can turn it into how people tow?

 

[alumi numb]

Re: why does the truck lift up

Just to confuse the issue....... wait until you drive a High Performance front wheel drive and it torque steers into another lane!!

half shafts are not the same length, that's why.

 

[HappierWet]

Re: why does the truck lift up

half shafts are not the same length, that's why.

Then WHY are they called half shafts....and not one side a Third shaft on one side and a Two third shaft on the other......or whatever?

 

[QC]

Re: why does the truck lift up

Well Macks with a 18 speed love it from 1600 to 2150

Yeah, and that's why we don't spec 18 speeds anymore although It is still my favorite tranny. I like flexibility, and I like being able to keep it wound down, as much as wound up. Depends on the load, the job, the grade, the speed etc. etc. etc. Nine speeds force them to do what you want. Good drivers can do more with more gears, bad drivers can break more with more gears . . .

 

[Bondo]

Re: why does the truck lift up

Well Macks with a 18 speed love it from 1600 to 2150 ,

Ayuh,... Sounds like you've been driving Detroits too long...
It's some Drivers that like the 18 speeds,...Lots a shiftin',+ lots a Noise....

We've got a fleet of Macks here ranging from 1972 to 2000,...5sp, 6sp,+ 9speed trannies...
They All pull like no tomorrow from 1100 to 2100...

 

[QC]

Re: why does the truck lift up

With a 400 rpm spread between gears,shifting at 1200 puts me at 800 rpm in the next gear-I'd be going nowhere real quick.

I think he meant downshifting . . .

COOL, an intelligent question about physics turned into a bash fest about driving techniques.

Why should this thread be any different than 99% of the others around here?

 

[alumi numb]

Re: why does the truck lift up

Then WHY are they called half shafts....and not one side a Third shaft on one side and a Two third shaft on the other......or whatever?

always seemed wrong to me also.
had a fiat 128 3p sport coupe rally edition chastion shadow louvers fogs air dam and stripes.
just another one i wish i had back, that thing flat handled!
know we shouldn't have done this but did.
nephew "350 4sp camaro" and i got into it in the town tight stuff and i ate him alive.
i'm just turning, thats all no big deal, he's power sliding and burning the tires.
in the tight's there was no way that camaro could keep up.
even by todays standard that's still a great handling car.

 

[alumi numb]

Re: why does the truck lift up

Ayuh,... Sounds like you've been driving Detroits too long...
It's some Drivers that like the 18 speeds,...Lots a shiftin',+ lots a Noise....

We've got a fleet of Macks here ranging from 1972 to 2000,...5sp, 6sp,+ 9speed trannies...
They All pull like no tomorrow from 1100 to 2100...

then there's that oh so wonderful 5.9 cummins, my baby.
no trouble at all lifting the front end, that thing called torque.

 

[Z71Man]

Re: why does the truck lift up

I hope we're all clear that torque cannot be dissipated as heat, only power can be. Ugh, not that I want to start another torque vs horsepower discussion....painful!

Just enjoy the pic!

 

[mla2ofus]

Re: why does the truck lift up

half shafts are not the same length, that's why.

I'd just like a good explanation of what the half shaft lengths has to do w/ it??
Mike