walking beams without leaf springs? what about shocks?

[CharlieFoxtrot]

Two totally unrelated questions:

Who has shock absorbers on their rears? Who doesn't? Discuss why or why not.

We have 2 trucks without leaf springs on their walking beams. I think they have elastomeric springs. Is that what those are? Please discuss the pros and cons of this system.

Bonus question: the only truck we have with shocks is the 06 Sterling with aforementioned elastomeric(?) springs. The Pete with a similar setup doesn't have shocks. Do you have any other comments about this?

thanks!!
kevin

[Jeff D.]

Who has shock absorbers on their rears? Who doesn't? Discuss why or why not.

Neither of my dumptrucks have had shocks front or rear.I don't know why not,but speculate that they either wouldn't provide a noticeable improvement,or possibly couldn't take the stress.All of my semi's have had shocks front and rear.


We have 2 trucks without leaf springs on their walking beams. I think they have elastomeric springs. Is that what those are? Please discuss the pros and cons of this system.

Two rectangular rubber blocks each side,set at a 45 degree angle??I imagine it's a simple design,and may be used for durability,at the expense of ride.


Bonus question: the only truck we have with shocks is the 06 Sterling with aforementioned elastomeric(?) springs. The Pete with a similar setup doesn't have shocks. Do you have any other comments about this?


No.

I would prefer having shocks,but don't know if there's measurable benifit when used in a dumptruck application.

[CharlieFoxtrot]

Neither of my dumptrucks have had shocks front or rear.I don't know why not,but speculate that they either wouldn't provide a noticeable improvement,or possibly couldn't take the stress.All of my semi's have had shocks front and rear.

I've always spec-ed shocks on the over-the-road trucks I've bought, but I know even in those applications, some folks consider them "one more thing to break."



Two rectangular rubber blocks each side,set at a 45 degree angle??I imagine it's a simple design,and may be used for durability,at the expense of ride.
.

Yup, that's them.



I would prefer having shocks,but don't know if there's measurable benifit when used in a dumptruck application.

In my somewhat uninformed opinion, they should pay for theselves in tire wear. It just seems to make sense. But we'll see...

thanks!!

[Squizzy246B]

A shock absorber should be correctly called a rebound damper. A spring being a spring and wise men of pyshics having written laws about Kinetic & Potential energy...and things about equal and opposite reactions when those energy's are applied as Force.....the spring will spring back and tend to cause the axle to bounce.

This is most noticeable in a single axle truck when backing up on soft ground unladen... or when in my old V8 Ford...ah..I digress:o . When the wheel loses grip and spins some of the surface away the axle drops and the spring bounces and so on and so forth..Axle hopping whatever you want to call it. Anyway..in a double axle with leaf springs the springs are linked, cantilevered...whatever you want to call it...so in effect...and more so when laden..when one wheel drops into a pothole and the spring tends to rebound its trying to rebound against the other spring... which is basically acting as a damper. One of the reasons why a double axle will back up on soft ground and a single axle will tend to get bogged in a dog t*rd on a concrete road:Banghead

Single axles should have sho...rebound dampers fitted and changed out every 2-3 years if working hard. Double axles really only need dampers if they have an axle hop problem, perhaps if you are operating on corrugated gravel roads or in the soft stuff a lot. A dynamic airbag system practically eliminates the rebound problem of leaf springs.

I imagine there is guzillions of trucks out there with knackered shockies...I mean dampers on them that have never been changed.

I think I'll start asking operators when the last time was they changed their dampers out...run a little survey

Just my Take on things anyway...and bugger it...just call them shockies:Banghead

[Jeff D.]

I do know that on air ride systems the shocks can be the only thing preventing the axles from hanging by the airbags, if the truck is lifted by the frame from the ground.

A friend had his ride height control valve fail, allowing the full 120 psi of air pressure to be fed to the bags. It was the middle of winter, he was empty, and he'd 100miles to travel to get to the shop. By the time he arrived all four of his shocks had the eyelets broken from the ends, and his bags were expanded far beyond what they were designed for.:eek:

I've occasionally check the shocks on my trucks to see if they were still working.(no leakage, warm up when in use) They've rarely needed replacement because of failure. The air ride cab shocks are another story. They are usually shot within 150K miles. They seem too small for what they're being ask to do.