Jake breaks in the rain

Over 54 years I have seen too many Jake brake experts watching the as* end of their trailer passing them. I spent many years driving through the Rockies in the winter months and would "never" have the jake on. Too many things can happen in a hurry if winter or heavy rain conditions change abruptly. The moment that trailer tries to pass you, you need every second of experience you have to get your rig back under your control: if you have the time and space to do so. I always played it safe, left the jake alone and drove in a mode I "knew" I can handle, no mater what.

 

I don't typically leave mine on in the slick stuff either. That being said, I will use it if there's a dry line where I can keep at least half the tires on dry pavement. If I see the dry line is going to disappear, I'll flip the switch off and go back to the brakes if needed.

In the rain, when it's warm out, I've never worried about it for the reasons stated earlier.

 

Rain, mud, snow, ice... I use Jakes under all conditions on new trucks. Current generation electronic engines will kill the Jakes if the truck senses wheel slip. Just like ABS. On older trucks (eg. mechanical engines), you need to be a lot more careful. That isn't to say that with electronic engines you can just "set it and forget it", but I haven't had one fail me yet. As posted by @Roberts450... I basically do the same.

It is a combination of engine and chassis electronic management, but I have seen it in every platform.

 

Having many hundreds of thousands of miles in the slickest conditions possible (extreme winter/ice/mud) over 35-ish years, I'm going to strongly disagree with your post.

Having the power (and engine braking) distributed across two to four wheel sets (two sets if no differential locks, four if all locked up) greatly reduces the possibility of breaking traction to begin with. If four sets, each set is only going to see ~25% of the power/braking. Additionally, with power being delivered to multiple, offsetting wheel sets, the vehicle dynamics are such that it will tend to keep it in a straight line rather than slew in any one direction (try turning ice-covered corners when all four wheels are locked--truck wants to go straight).

Typically, drivers that operate in a lot of extreme conditions use their inter-axle and differential locks continuously. I would lock the inter-axle in at the beginning of winter and unlock it in the spring whether off highway or on. I also use the differential locks in all conditions, even on the highway, if warranted (up to their maximum operating speed--there is no such restriction om the inter-axle). And I would use all at all times of the year in slick mud conditions.

 

Lot of people here should study how power dividers and/or locking rears actually work before giving advice.
I would explain but they would learn more by doing the research themselves.

 

No kidding. But then again I went to diesel mechanic school before becoming a driver so I have actually had a complete class 8 drivetrain in pieces before.

 

Your advice is spot on.

Earlier in this thread someone advised to stay within what you KNOW. To this I would add that you need to PRACTICE BEFORE you need to know.

For example, the next time you are bobtail on ice in a parking lot, try the following experiment:

WITHOUT the power divider engaged, put it in 4th from a standing start and then give it full throttle. I will bet my mortgage that you are going to spin out (yaw) to the left. That's because without the IAD engaged, if any wheel spin happens because of poor traction all the power gets transferred to the right rear tandems.

Now engage the IAD and try the experiment again. You WILL notice that you won't yaw at all.

Now try running it up to 20 mph and engage the Jakes on full, with and without the IAD engaged. You WILL notice that with the IAD engaged you will not yaw (start going sideways).

The MOST important point is to PRACTICE BEFORE you get into deep kimchee. I learned to drive in the PNW. Whenever there was a moisture heavy snowfall my dad took me to an empty parking lot to play in the snow. Do the SAME THING in your truck. PRACTICE.

I cannot disagree strongly enough with the posts from @lilillill. The advice is downright dangerous.

 

The Interlock is another componet.

In my day throwing that in locks your drives together more or less and as a result that truck only knows the langauge "Straight" Anything else forget it. Sometimes that is a asset. It's beyond the topic to expand further on theory and how I use the interlock myself. But it is used certainly.

 

Yes,this is good advice.Just like why they "had the posi"track on the old 400hp muscle cars.

 

I don't actually recommend trying this,but..if you sandwiched a 351 crate motor into an old "Ford Fairmount with a "live rearend" then mashed the gas from a stop,you would more than likely "fishtail" and go straight in the ditch" Put a Position on same car" one tire spins then power goes to the one Not losing traction"keeps you in a straighter line.JMO