the unnecessary usage of j-brakes, why????

In a lot of places you can get a ticket.Ive heard Cal.is one so whats the deal Ive never seen or heard of anyone in Tx.getting a ticket for boom ka boom boxs.Whats funny they ride around with all the windows down no matter how hot are cold it is

 

Yes maybe they are practicin to race a JBH truck!!!

 

Just think whet that is doing to their hearing too.

 

YeAH!

WhaT?

 

The second thing I turn on in my truck when I start it is the Jake brake. The next to the last thing I turn off when I shut down is the Jake brake. My reason is all the help I can get stopping everywhere and 750,000 miles out of a set of brake shoes.

 

Are you aware that the excessive use of Jake type brakes can cause tire wear problems?

 

My brother does the same thing
Hey shocky how could it wear your tires?

 

You WOULD have to ask.

Ok, I'll try'ta 'splain,................................
Just keep in mind this information came from a long-time mechanic who specialized in drive trains on -- or under -- Big trucks.

~~~~~ DISCLAIMER ~~~~~
I, ShakeyAfterShock, Do NOT accept any responsibility for the accuracy of this information
And/Or
Liability of same.

Never Bet The Farm On The Following Information:

I've known a few really good mechanics who git 'er done right, --- and usually the first time.
One of which knew Big truck transmissions, of the non-automated kind. You know, real transmissions.
That guy could open a transmission and tell y'all how the driver drove it --- buy the wear patterns on the gears, and a few other secrets he wasn't willing to share.
But his evaluations were right on the money.
*Unless it was a Big company company Big truck.
With all the newBee drivers and gear-jammin' nimrods who've driven them, it's hard to tell, he told me.

But that's not the mechanic I was gonna tell y'all about.
Nope.
One of the other mechanics was a suspension and drive train specialist, and worked for Good Year Tires, at the time, aligning, balancing, rebuilding, customizing, well, .... he did it all, and, as a result, was in demand.

I caught him during an idle time and bought him lunch from the catering truck in exchange for a little information.
He agreed.

I mentioned that I had read, somewhere, that the use of Jake type engine brakes could have an adverse effect on tire wear. ..... and I wondered if that was twue, and, if so, Why and How?

He told me that when an engine brake is deployed, it's basically turning the Big motor into a compressor, of sorts --- which creates a resistance, and a sort of reverse torque on the drive line.

The weight and possibly gravity are pushing the loaded Big truck. If it were freewheeling, there would be minimum resistance and the speeds would probably increase.

The transmission and rear gears are being influenced by the rotation of the drive wheels, making the axles and drive shaft attempt to turn the Big engine faster, -- depending on what gear the transmission is in at the time.

With the engine brake on, it's creating waayyy more back pressure than if a driver were down shifting to decelerate without the engine brake. The Big engine, by itself, would not create or provide as much resistance, as the load pushes the rpm's , and road speeds, higher.

Engine brakes provide additional resistance from the Big motor.

But,........................

All that creates certain vibrations and harmonics that can transfer back, through the clutch and transmission main shaft -- to the drive shaft, U-joints, ring and pinion gears, axles, hubs, wheels, ...... and finally, tires.
I reckon that's where the rubber meets the road they're always talkin' 'bout.

The results of the tires trying to resist increasing speeds at the same time they're trying to roll faster, can cause a slippage, or 'scuffing' action that isn't present when only the service brakes are used, w/o running the Jake brake.

The drive tires can be "read" by a good mechanic --- and the results are usually unusual cupping. Out of alignment rear axles can effect the cupping and create additional vibrations and harmonics also.

He told me many mechanics see that as a balance and/or alignment problem only, and it could be. But when the strange cupping persists after balancing and alignment -- they're at a loss to explain it, so he sought an answer.

What he discovered was that those tires with the worst wear, were from Big trucks with drivers who used their Jakes a LOT -- and usually without using a lot of their service brakes. And the very worst of the tires were those that ran heavily loaded as a steady diet while using their Jake, and goin' easy on the brakes.

He suggested that it's probably best if a Big truck truck driver uses a combination of reducing to a lower gear,
application of service brakes
along with the Jake, --
EVEN IF the Jake could hold 'er back all on it's own. The combination of the three items listed above kinda balances thangs out. He called it "setting the driveline" or "getting a set" (on the driveline).

He said that was sorta like what race car drivers sometimes do when coming to a turn.
Rather than "lift" (the accelerator pedal) -- they'll stay pedal to the metal and just tap or ride the brakes instead which, not only slows the car, but causes the suspension to kinda re-adjust how the horsepower and torque is bring distributed to the ground and how the resulting weight transfer and re-distribution can affect the handling of the race car.

Done properly, it can increase speeds on track. Productive.
Done improperly, the possibility of scuffing (sliding) a tire is a common result. Counter-productive?
Could be!

Now, I don't know if all that makes any sense, or not ------
but it sure sounded good when I wrote it.

I've never heard of a comparative cost analyst betwixt the cost of using less service brakes and more stresses on the drive line and tires though. But I'd rather replace service brakes than have to open a gear-box or engine.

And if y'all can imagine a Fantastic Voyage into a Big truck drivetrain, like I can, .... I can see where those observations and deductions could be possible.

Besides, when y'all are tryin' to change the subject from baby-dolls to sumthin' the CB jabber-jaws will have to think about, this theory will keep 'em quiet for a minute, maybe two --- before they come up with their usual answer -------
SheT up --- StoopiD!!

It's twue!
It's twue!

Did that answer your question, Baack?

 

So the vibration sending a "Aftershock" through the drive train creates un- even wear?
OK maybe
Thanks

 

I Would Say It Depends On Your Tires. I Had Dunlops On Truck When I Bought It And Got About 140k Mileage Then Went To 726's And Pulled The Last One Off At 600k Whith 1/64th Thread Left. I Did All This While Pulling A Shotgun Tanker 3yrs And A Flat 2yrs. Don't Think That's To Bad With Constant Use Of Jake.