steve_24v:
Correct me if I’m wrong but I find the way to get a 124/420 3/3 fully freighted moving is:
1st high to 2k revs
3rd low to 2k revs
4th low
5th low
5th high
6th low
6th high
With that sequence you don’t need more than 1300/1400 rpm max in 1st & 3rd with a 124/420. Revving to 2k your not using the torque band effectively, let it lug!
Payed more attention today and I do seem to hit 1600-1800 in 1st and 3rd…
I’d always felt the power to be in the 1200-1400 range, if that’s right then that’s what I’ll use ? Problem I find is that you can’t rush the gears, so by which time the revs have died a little, hence the 1600-1800
When I first started regular driving, in a FH12 420, I was instructed to hit the 2k mark while pulling away loaded, not knowing any better it felt the right thing to do, no ?
On the limiter the rev’s are a nat’s under 15k, the green band is 10-17k. yellow 17-25k. Didn’t really think the odd 2k to be a problem ?
While we’re at it, how low do folk let the revs go before changing gear ? If it holds above 1k I usually leave it… or not, depends
Payed more attention today and I do seem to hit 1600-1800 in 1st and 3rd…
I’d always felt the power to be in the 1200-1400 range, if that’s right then that’s what I’ll use ? Problem I find is that you can’t rush the gears, so by which time the revs have died a little, hence the 1600-1800
When I first started regular driving, in a FH12 420, I was instructed to hit the 2k mark while pulling away loaded, not knowing any better it felt the right thing to do, no ?
On the limiter the rev’s are a nat’s under 15k, the green band is 10-17k. yellow 17-25k. Didn’t really think the odd 2k to be a problem ?
Some Scania’s are particularly slow at changing through the range, if your unlucky enough to have one of those then 1500/1600 max is all you should need without losing enough road speed to cause a problem. Revving to 2k is unlikely to cause any permanent damage but it does make the motor sound awfully rough and will have a big impact on fuel consumption, plus if you are revving to 2k as you go from 1st into 3rd you will get clutch wear, the clutch is not designed to engage at that speed even when empty.
While we’re at it, how low do folk let the revs go before changing gear ? If it holds above 1k I usually leave it… or not, depends
Yep! that’s OK, let it lug, anything above 1000rpm is good provided you are not losing too much momentum, it depends on the prevailing conditions.
Ideally the power should be kept in the green band, but if there is a hill up or down you have to adjust the gears accordingly.
Tachometers marked in green, yellow and red are a good idea for a new driver to a new truck.
I was recently brought up with ZF Ecosplits on DAF which had yellow arrows, up or down. the trick was to get it in the right gear before it told you to do so