What Is A Retarder And When Do You Use It?

[Dwight Hut Pizza]

So now that I've been playing this game long enough I am starting to use the more advanced functions and went to the controls to put keybinds on more things. I understood pretty much everything but then I came across retarder. Can someone please explain what this does and when I should use it please? Thanks.

[Reese]

Without having the technically background knowledge, the most I can give you is a concept explanation.

A retarder is braking mechanism on the end of the transmission that uses fluid to evenly distribute braking ability to all powered wheels on the primary mover/unit/tractor. You would use it in any situation that you'd use an engine brake in. Most American trucks do not have a retarder installed, instead opting for an engine brake if any external brake at all.

Perhaps a European who knows more about the retarder will reply with more info, info that is definitely more accurate than mine.

[AyMazingATS]

There are two different types of braking in the game besides your service brakes(brake pedal.)

You have an an engine compression brake also known as a jake brake. Everyone has heard one of these in the real world.

From Wikipedia...A retarder is a device used to augment or replace some of the functions of primary friction-based braking systems, usually on heavy vehicles. Retarders serve to slow vehicles, or maintain a steady speed while traveling down a hill, and help prevent the vehicle from "running away" by accelerating down the hill. They are not usually capable of bringing vehicles to a standstill, as their effectiveness diminishes as vehicle speed lowers. They are usually used as an additional "assistance" to slow vehicles, with the final braking done by a conventional friction braking system. As the friction brake will be used less, particularly at higher speeds, their service life is increased, and since in those vehicles the brakes are air-actuated helps to conserve air pressure too.

There are also several different types of retarders. Hydraulics which uses viscous drag forces between dynamic and static vanes.

There is also electric retarders, which uses electromagnetic induction.

American trucks for the longest time never used retarders. It was a European thing. Though still not widely used in the USA more trucks are being equipped with retarders.

[Sandhill]

Originally posted by AyMazingATS:

American trucks for the longest time never used retarders. It was a European thing. Though still not widely used in the USA more trucks are being equipped with retarders.

Retarders have, it seems, been used quite a bit in the USA on Allison automatic transmission equipped buses and the motor homes built on bus chassis. I do not follow it closely, and was unaware that retarders were being used in any other application.
An obvious advantage of the retarder over the Jacobs type engine brake is that retarders are almost silent, where Jake brakes are more and more banned because of the noise. European standards seem to require quiet running, and I assume that is the biggest reason that retarders are common on trucks in Europe and nearly unheard of here.

[Hiro Protagonist]

Originally posted by Reese:

Without having the technically background knowledge, the most I can give you is a concept explanation.

A retarder is braking mechanism that uses fluid to evenly distribute braking ability to all wheels on the primary mover/unit/tractor.

Only to the driven wheels.

Think of the retarder as a load on the back of the transmission, similar in concept to an exercise bike or rowing machine. It provides resistance to the turning of the driveshaft in direct proportion to the speed (ie the faster the truck is travelling, the more resistance the retarder provides).

[drufus59]

use with cruise control to help stop speeding

[The Governor]

The Jake brake and retarder are actually one and the same. The definition of retarder is any device other than our standard brakes that is used to slow the truck. In this case the jake brake is also known as a engine brake or engine compression brake, and its function is that it releases compression to make the engine pull back the truck.

Its most commonly used on steep grades. In real life I drive a 2018 kw t680 with a isx cummins and 10 speed. When I'm approaching a steep grade like 5% or higher, I can kick the engine down to gear 8 and turn on the jake, and my engine will hold a 43,000 lb load at 60 mph. Great for areas like Donners pass, Cabbage hill, Cajon pass, and Grapevine.

I also like to keep it on in cities because traffic is known to be erratic at times, and the extra slowing power really comes in handy when freeway rush hour traffic goes from 65 to standstill. Now you may say that there are signs saying no engine brake or compression brakes within cities but those are because of noise ordinance and not actual function. My jake is muffled and you can barely hear it when its functioning.

ps: The state of colorado actually requires muffled jakes statewide and I believe its a $500 fine if they arent.

The only time they really shouldn't be used is in poor weather as the jake may make the drives skip, or stutter. This can be bad because while the jake affects the drives, it has no control over the trailer tandems which still want to move at full speed. This could in effect lead to the trailer pushing on the truck, pushing your drives out from under you, and next thing you know youre jackknifed in the median.

I'm surprised the wiki there says its not common in the US. Personally I love my jakes and I live by them. Best vehicle invention in the world if you ask me. I hate that in game you have to hold the button down to make it work instead of being able to just keep them on.

[Reese]

Originally posted by The Governor:

I hate that in game you have to hold the button down to make it work instead of being able to just keep them on.

Actually, there are 2 engine brake buttons you can bind. One is a toggle, the other is a hold. :)

[Sandhill]

Originally posted by The Governor:

The Jake brake and retarder are actually one and the same.

As we said above, retarders are very uncommon in the US and many have no clue of what a retarder is. They retarders and Jake brakes are only similar in that both resist forward motion and aid speed control, lessening reliance on the service brakes.

[pieperjohanns]

Originally posted by Sandhill:

As we said above, retarders are very uncommon in the US and many have no clue of what a retarder is.

Technically he was correct, though, as every automotive engineer could confirm.

But in common language engine-mounted retarders are called engine brakes, and only transmission-mounted retarders are called retarders.

Originally posted by AyMazingATS:

You have an an engine compression brake also known as a jake brake. Everyone has heard one of these in the real world.

Jake brakes are a North-American thing, by the way. European trucks use mostly engine brakes that work by closing the exhaust directly behind the engine or behind the turbo charger.

[Sandhill]

Originally posted by pieperjohanns:

Originally posted by Sandhill:

As we said above, retarders are very uncommon in the US and many have no clue of what a retarder is.

Technically he was correct, though, as every automotive engineer could confirm.

But at that point of broad definition service brakes and even a driver's hand out the window or boot out the door and dragging on the pavement are "retarders".
In the context of the game, and assigning buttons to functions in Options, they are clearly different, and I suspect that that is what the OP was asking about.

[The Governor]

Originally posted by Sandhill:

Originally posted by pieperjohanns:

Technically he was correct, though, as every automotive engineer could confirm.

But at that point of broad definition service brakes and even a driver's hand out the window or boot out the door and dragging on the pavement are "retarders".
In the context of the game, and assigning buttons to functions in Options, they are clearly different, and I suspect that that is what the OP was asking about. :lunar2019smilingpig:

No, the definition is devices used to slow down the vehicle other than service brakes. And sticking your hand out the window is grasping at straws, especially as your hand is not a device.

https://en.wikipedia.org/wiki/Retarder_(mechanical_engineering)

#1 item that they discuss is in fact the Jake. By releasing compression in the engine, the engine itself pulls the semi back, helping it hold its speed on downhill grades, The higher the compression (the lower the gear), the more pull you receive. For example, California law says trucks may only do 35 mph down grapevine (I-5). So in my real truck I get down to 6th gear and have to run between 1st and 2nd stage jake. 1st is too weak, and I slowly gain speed, and 2nd is too strong and I slowly lose speed. If I do max jake (3rd stage) I will lose enough speed that my truck will actually downshift to 5 and eventually 4



But....

I dont have to use my service brakes. My doing so I avoid extra wear and tear. Also, as service brakes heat up, I would experience brake fade. The hotter they get, the less stopping power they have. And if I continue with this action, I can eventually smoke my brakes, which can possibly lead to brake weld or a trailer gone up in flames.

The OP's question asked what it does, and I told him. As I said before, i love the jake and I live by the Jake, Still shocked that its stated its uncommon in the state because its standard issue in all our fleet trucks.

[The Governor]

Originally posted by Reese:

Originally posted by The Governor:

I hate that in game you have to hold the button down to make it work instead of being able to just keep them on.

Actually, there are 2 engine brake buttons you can bind. One is a toggle, the other is a hold. :)

I'll take a look into this in a few. Thanks!

[Sandhill]

"The Jake brake and retarder are actually one and the same." This is simply not true.

The question was not about the dictionary definition of retarder (the hand out the window, open or grasping at straws is indeed an aerodynamic retarder by that definition) but about the definition within the highway transportation industry and specifically within ATS.
Retarders and engine brakes are two entirely different things which only share a single purpose but otherwise have nothing in common, they even work differently depending on conditions (vehicle speed, engine rpm) and really are not even functionally interchangable.

[The Governor]

Originally posted by Sandhill:

"The Jake brake and retarder are actually one and the same." This is simply not true.

The question was not about the dictionary definition of retarder (the hand out the window, open or grasping at straws is indeed an aerodynamic retarder by that definition) but about the definition within the highway transportation industry and specifically within ATS.
Retarders and engine brakes are two entirely different things which only share a single purpose but otherwise have nothing in common, they even work differently depending on conditions (vehicle speed, engine rpm) and really are not even functionally interchangable.

I literally linked you the definition. But you do you I guess. Me and the company I work for will continue calling it Jake and/or retarder.

[Sandhill]

Originally posted by The Governor:

Originally posted by Reese:

Actually, there are 2 engine brake buttons you can bind. One is a toggle, the other is a hold. :)

I'll take a look into this in a few. Thanks!

Better yet the strength of the engine brake is changeable at least during a single game session, so you can choose one of I think 3 settings at which the engine brake engages when you lift throttle, change the setting on the fly, and have that setting remain throughout the session until you change it, so you can match your brake strength to conditions.