coasting instructions

[john fox]

IMBSB many years ago I looked inside a now unmemorable type of truch exceot it was definitely American and I think probably a WW2 3 axle truck which had had a beautiful paint job including stenciled across the top of the cab the words: no long distance coasting

 

I have always wondered:

a) what is coasting - is that in gear but with foot on clutch or is it with box in neutral out of gear?

b) why is it prohibitied and does that apply only to that specific US truck?

 

Please educate me before I get older and/or destroy a different vehicle to which this driving style applies but of which I am ignorant. If I undertand coasting to be as defined in a) above I do that all the time on down slopes in my car to save petrol!

 

John

[David Ives]

most vehicles when coasting tend to lose brakes as engines conected to air or hydrolic pumps also loss of rev control on driveshafts

best advice dont as will also wear clutch more when taking up drive again

[fv1609]

 

I do that all the time on down slopes in my car to save petrol! John

 

John do you even do that down hills where there is a sign "STEEP HILL ENGAGE LOW GEAR NOW" ?

 

The reason being that otherwise you rely solely on the brakes for regulation of speed, but by being engaged in a low gear, the gearing has a restraining effect on the speed you descend. Even descending more modest hills I like the reassurance of the engine & gears regulating my speed, rather just hoping the foot pedal will keep it under control.

[Rick W]

I think you'll find that coasting is either illegal or certainly a no-no in the highway code as it infers you are not in complete control of the vehicle!

[john fox]

John do you even do that down hills where there is a sign "STEEP HILL ENGAGE LOW GEAR NOW" ?

 

Sure do - all adds to the excitement of driving especially at the moment where I am working in Bath - the entire place is surrounded by hills and I reckon I get to work on half the petrol everyone else uses. I especially like the way i catch everyone up on the downhill sections too :-D, makes it much more interesting given that the West Country folks don't seem to know they have a 5th gear and also seem afraid to use 4th gear most of the time :shake:

 

(Brake pads are cheap to replace!)

 

Ok I'll subscribe to our :police: state in future and drive properly, lesson learned - thanks guys :whistle:

[David Ives]

john even thougth i live in sussex now i be a westcountry lad :whistle: and use all gears available :-D :-D :-D :-D

[john fox]

john even thougth i live in sussex now

 

Halleluiah, :angel: the man has seen the light and moved to an almost proper part of the country, finish it off and move next door to God's Own Living Paradise - Surrey :evil:

[David Ives]

but i go home carnival night for a reunion with the old scrump :-D :-D :-D

[Degsy]

Coasting = Aberdeen overdrive as it was called by the truck drivers years ago when the speed limit was 20mph and all trucks were very underpowered. A good driver cut a couple of hours off the London to Scotland time by coasting down hill and getting upto maybe 60mph and using this speed to climb the other side of the hill. Some cars (Rover was one) were fitted with a freewheel device as a general economy feature. If you do coast DON'T TURN THE ENGINE OFF, apart from the effect on brakes a catastrophic explosion can occur when you attempt to restart the engine.

[Tony B]

Sure do - all adds to the excitement of driving especially at the moment where I am working in Bath - the entire place is surrounded by hills and I reckon I get to work on half the petrol everyone else uses. I especially like the way i catch everyone up on the downhill sections too :-D, makes it much more interesting given that the West Country folks don't seem to know they have a 5th gear and also seem afraid to use 4th gear most of the time :shake:

 

(Brake pads are cheap to replace!)

 

Ok I'll subscribe to our :police: state in future and drive properly, lesson learned - thanks guys :whistle:

a little lesson :angel:I've learnt the hard way over the years. The best brake you have on any vehicle is the engine. Pads or shoes fade with heat down a hill, gears don't.

[Richard Grosvenor]

a little lesson :angel:I've learnt the hard way over the years. The best brake you have on any vehicle is the engine. Pads or shoes fade with heat down a hill, gears don't.

 

And if you're driving a truck with a Jake Brake they sound loverly coming down a hill! :-D

 

And do people really turn their engine off while coasting? :shake:

 

Richard

[Tony B]

Hopefully they don't survive long enough to breed. :sweat:

[Markheliops]

Sorry - have to put my input in here.

 

Can't believe some members are coasting their vehicles. :what:

 

You should NEVER NEVER NEVER coast a vehicle down hill.

 

This is advised purely on the grounds of safety to you and other road users.

 

Many vehicles, old HGV (our vehicles) will not build up sufficient air if coasting is employed to gain more speed. Air will not be replaced in the tanks as quickly as the engine will only be in tick over.

 

Also, vehicle brakes will tend to over heat (brake fade) as the engine is not being used to give added braking to the point when the brakes will have no effect when trying to stop.

 

Also, excessive speed will have a direct effect on steering - IE the control of the vehicle.

 

Coasting is an extremely dangerous thing to do and very foolish.

 

Markheliops

 

 

[Richard Farrant]

 

You should NEVER NEVER NEVER coast a vehicle down hill.

 

Coasting is an extremely dangerous thing to do and very foolish.

 

 

 

Totally agree Mark,

 

When I was working in REME workshops, back in the 70's / 80's era, there were still a lot of the old 30mph flat out wagons in service, also some newer ones. I rebuilt quite a number of AEC engines where con rods had gone through the block because the driver had freewheeled down hill and let the clutch back in at too high a road speed, mainly AEC Militant Mk1 and Thornycroft / Aveling Barford Dumptrucks. Crazy practice on a vehicle with air brakes, or in fact any vehicle and as already point out, ILLEGAL :police:

 

Richard

[N.O.S.]

Coasting = Aberdeen overdrive as it was called by the truck drivers years ago.............. Some cars (Rover was one) were fitted with a freewheel device as a general economy feature.

 

Also known as "Angel Gear", and the SAAB 80 had freewhel - a most horrendous experience getting around corners unless you braked well beforehand and powered into bend (yes I know you should anyway, but if you got caught out it was almost 'brown bag' time :shake:

[Dakman]

 

When driving old slow vehicles, with vacuum, single-line air or just plain old braking systems, and horrendously low power-to-weight ratios, (and yes, I've driven quite a few), the best piece of advice was given to me in the early seventies as to how to drive and pass a PSV test on an old crash-box Bristol 1/2-cab, and that was simply this:-

 

GO DOWN THE HILL IN WHATEVER GEAR YOU HAVE TO USE TO COME UP IT.

 

Best-ever bit of advice I was ever given, and on really steep ones, HOLD the gear-lever

in the gear in case it should jump out!

 

Yes, it makes for a few very slow descents, but you'll always live to tell the tale, IMHO.

 

;-)

[Mark]

Good advice

[john fox]

When I was working in REME workshops, back in the 70's / 80's era, there were still a lot of the old 30mph flat out wagons in service, also some newer ones. I rebuilt quite a number of AEC engines where con rods had gone through the block because the driver had freewheeled down hill and let the clutch back in at too high a road speed, mainly AEC Militant Mk1 and Thornycroft / Aveling Barford Dumptrucks. Crazy practice on a vehicle with air brakes, or in fact any vehicle and as already point out, ILLEGAL :police:

 

Richard

 

 

Thanks Richard

that answers my original question as to why it was importantly stencilled in the cab of a Jimmy(??)

As for the rest of my comments :banme:

[Tony B]

The Land Rover instructors drilled into me, up them high and fast down them low and slow. The speed for the conditions the gear for the speed.

[antarmike]

My wifes scammell explorer has "do not coast" painted twice in the cab, but that I always thought is because parts of the gearbox will be turning without the gearbox oil pump being driven and therefore lubricating those moving parts. I used to coast my Matador and I had 55 mph out of it on the hills down to Honiton, but I have grown up a bit now!

[abn deuce]

This is a great example of how and why this Forum works ! We ask questions and Learn from each other so that we are all better able to enjoy our Vehicles Safely

[Mark]

This is a great example of how and why this Forum works ! We ask questions and Learn from each other so that we are all better able to enjoy our Vehicles Safely

 

 

True, very true

[Bodge Deep]

My dad has one of the old 'freewheeling' Rovers, a 1937 sports saloon.

Basically power is delivered to the back wheels in the same way as a bicycle...

 

Plus side - clutchless gearchaning (& alleged) better economy

Drawback - no engine braking so it'll run away with you downhill... nice :shake:

 

oh & you can't engage & disengage the mechanism whilst the vehicle is moving so you have to ride your brakes downhill mmm scary!

[Tony B]

Try the old Morris with cable brakes. Going down the hills FEELING the cables stretch. :shake:

[Dakman]

 

 

The old Midland Red D9 (BMMO) double-decker 1/2-cab had hydraulic brakes, pressurised

 

by a pump on the gearbox drive-shaft, (fluid flywheel, separate gearbox). So when at rest

 

or moving or shunting slowly, you had NO footbrake! Ever tried to hold a fully-loaded bus

 

against an engaged fluid flywheel with a long elastic-like handbrake only? It called for

 

a quite unique juggling act and a very strong arm! Once well and truly under way, the

 

brakes were very good for the time, but coasting was of course out of the question, as

 

the pump was on the input side of the remote gearbox!

 

 

 

 

 

[Jack]

If you do coast DON'T TURN THE ENGINE OFF, apart from the effect on brakes a catastrophic explosion can occur when you attempt to restart the engine.

 

This sounds interesting - why would it go bang?