What are the pros and cons to air suspensions on dumptrucks? I've been looking off and on for awhile now and found a 1994 Kenworth W900 that looks to be in good shape and in the price range I can afford. The only downside if there is one would be the air suspension. I'd really like to understand the differences, but I'm not finding much with my google searches.
We have two Kenworths T800 1991 models. It seams like every other year or two we are having to put new bushing in between the axels. We have also broke the piece comming down between the axels off the frame that keep the axles in line and connects them to the truck a few times. Our trucks go off road a lot to. I thank if you can keep them on the road more they will be alright. It takes a little while to get used to the air suspention when loaded heavy, it likes to rock a little and lean going around corners. You just hug the seat a few times you'll get used to it. This is just what I have experienced. Hope it helps. We just bought an 04 Pete with drop axle. Both are good trucks.
A company we work with now and then have a T800 with an air suspention and the guy says he'll never own another. Like Woodstock says its tippy. I know they have to dump the air out of it everytime they dump it. He also said ya had to be careful because it would get stuck on the crown of the road. I personally never drove the truck but have no reason to doubt him. We bought a T800 a while back and had them change the suspention from an airbag to a Hendrickson spring. I think the Chalmers is the best one out now. IMHO.
i live in the same area and what ive heard from truck drivers is that the air suspension is just fine working mostly on the road but doesnt do as well offroad. Last place i worked for had a pete with air bags and it was used offroad a lot and was always breaking something. It had also been on its side once from not dumping the bags and dumping rock on a slight sidehill.
One of the machanics here said that you need to seperate the sides and make them independent each with there own acuater (sp) so the side with the most weight will inflate it keeps them from tipping over. Stock there is 1 senser to inflate both sides and there lies the problem causing them to tip. ( the heavy side causes air to crosover to the light side raising it higher causing the tipover. I drove one of there trucks, a converter OTR Mack with air and it was a pleasure to drive and there was no need to dump the air before raising the box even on a slight side hill. I personaly have hendrickson on all 3 of my trucks. but hear the same about chalmers been the best.
you need dual leveling valves,that helps some. look for an 8 bag or go spring :my2c
This the AG-400 8 bag suspension from kenworth, they released it in 2003, supposed to increase roll-resistance and add side stability!
About the only dump trucks with air-ride around here are those hauling asphalt or bulk materials that do not go offroad. All the excavators and independent truckers hauling construction material have spring or walking beam suspensions. The last job I was on, a guy with air-ride brought a load of gravel for the driveway-he had to dump the airbags before he backed in, and went about 10 feet before being bogged down in the mud. He said his next truck won't have air bags. I don't know about the new 8 bag systems, they look like they may be alot better.
i know here in michigan 90% of the trucks short doubles graveltrains all have air ride with no problems. and dont have to dump the air. the one that i drive scaled out at a 150000 lbs and i never had to dump the air, i was always offroading.
Jperfect, how many axles are you running on a truck grossing #150,000, and what kind of terrain and off road conditions do you have there. I'm just guessing, but I'd think a truck trailer combo with 12 or 13 axles would have to pretty stable no matter what type of suspension. I'd also bet that it is very flat where you are with very sandy soil. Quite a different situation than a tandem axle in hilly terrain and muddy clay!
I love air, wouldnt ahve it any other way, yeah they roll more but you get used to it. Dump the suspension and dump it. Once you go air you wont go back, keeps the truck from rattling apart.
the two petes we have are air ride ,its nice on the road and on hard gravel but off road you need to lock the rears and the axles to keep moving on uneven or slick ground. my truck is on springs (walking beams) rides ok, rides a lot better loaded but no problems in the mud or uneven ground. as for dumping the bags, the guys who drive the two petes do it before dumping, they say if you don't when you dump the truck the load comes off faster than the bags can adjust and they will over inflate and may pop:beatsme thats what they say , i wouldn't what to be the one to try it ok with that said if you work mostly on hard surfaces than i'd go with air , if not than it maybe more of a pain in the butt
:my2c I think the answer is like any machine - depends on the application. Walking beam is the best for a construction truck that is going to spend 20-30% of its time off-road. The other 70-80% of the time the dump is running inner city not over the road. The ride is important but you need the ability of a walking beam off-road. If I was running asphalt, dense grade or contract hauling primarily on the road I would go with air ride for two reasons: ride quality and it is easier on the truck. Also most of your used dumps with air-ride are over the road trucks converted to dumps. Over the road trucks are spec'd different than construction trucks. The trans., gearing, suspension, ect are usually not as heavy spec'd as a construction truck. This could be contributing to the problems some folks have with air ride dumptrucks.
I talked to a couple of folks yesterday (one driver and their truck mechanic) and they echo much of what's been said here. Considering much of the time I'm on pavement or good gravel, the smoother suspension sounds pretty good to me. My off road work is really limited to small new home sites and that doesn't last long once I start spreading gravel. I guess I won't write off the air rides yet Anyway, thanks for the information and discussion.
I guess i should add that the pete at my old work actually held up alright considering i had seen air under the tires on it a few times Moving brush around on site and they couldnt drive threw the mud so they tried flying over it
we have a lot of mud right now, but we have alot of clay, sand, rock. the area that i live in is pretty hilly. we are only aloud 11 axles. this trucks go all over job sites. tring to find some pics.
My Western Star tri-axle has Chalmers and I like it a lot. With an air ride cab and the air ride seat, it isn't too bad unloaded (although not near as nice as air ride suspension). It rides real smooth loaded. I do go off road a lot and that is where it shines. I hardly ever have to engage both axles. When one set of tires is pushed up, it drives the other tires into the ground. My buddy with the air ride Pete is always engaging his especially when empty just to get out of a jobsite. Also, there is very little that goes wrong with the Chalmers - cheap to run. And it is lighter than springs and therefor allows for more payload. I would say the same as the others on this thread. If most of the driving is on road, go with air ride. If a fair portion is off road, go with Hendrickson or Chalmers. I have also heard that the Volvo/Autocar spring ride is very smooth and also good for off road. It is, however, expensive to run/fix etc.
Hey Bob- Is that spring ride suspension you are referring to the T-Ride ( I think that is what it is called.) I was just wondering- looking at a Volvo VHD for a tri-axle and I don't know that much about them although they look like good trucks.
The T-Ride is it. I run into a guy from time to time that has a fleet of dump trucks (Pete, Kenworth, and one Autocar). The Autocar has the T-Ride and he is always driving it. He could drive any of the other trucks but says the T-Ride is the best riding truck he has and that's why he uses it. If you look at one you will notice it looks different than most other spring suspensions.
The T-ride looks like it could handle the 46K rear ends that are under some of them. I am use to seeing Chalmers or Hendrison (sp?) just didn't know much about the T-ride.
Quite a few trucks here are running air bags. A good friend of mine just picked up an '89 Pete 379 with air. He said he doesn't mind it, although he agreed that walking beam would have been a little better for the long run. Just remember to dump the bags before raising the box.
http://www.novitruck.com/Used_Trailers/Mac_002416lead.htm Heres a link for a pic of a Mi gravel train.
hey thanks crash. are you guys busy on that side of the state.nothen over here
My brother was the one who ran the train for about 10 years (drove for Cordes), he just talked to another driver from there and they are pretty slow right now, hauling scrap mostly right now plus the frost laws are in effect. give them a couple of weeks and things will get busy again. But were busier than we want to be pulling 53' vans running to PA and IA. Got a truck with a sleeper? call me, ive got work.
Hi folks ,as an owner poerator of a small dump truck compay and been in this bussines for 20 years I can say that I have plenty experience on this matter. currently I have a KW T800 H with new way air suspension that it's rated at 46K # the ride can not be better and when Im off roading ,if I lose traction I'll engage the diff locks and am good to go ,I still havent seen a truck with walking beam that does not have the diff locks ,so if I have it I'll use it ,I had a Pete 378 with low air leaf 40K# and I miss that truck a lot My other truck is a 378 with chalmers and im willing to swap it for the air leaf any time ,I also challenge anybody to replace a boken spring from a walking beam on the road side in 20 minutes like I can replace an air bag on that time with hardly any tools ,witch I never had to do because air bags dont brake as usual as spring leafs and let me point that my trucks are try axles with a pay load of 23 tons thats running 100k miles a year.
2109 Stang - Did the 378 Pete with the low air system have ground clearance problems off road? I have heard they are limited off road because of ground clearance but ride real well on road. I have a friend that runs a number of Pete transfer units and goes off road a lot and won't run the low air system because of this. He says the air leaf system is OK off road.
The toughest suspension is the solid mount that Hendrickson makes for the ready mix trucks. Second toughest is Mack Camel back you have very little problems with that type of suspension. The Volvo T ride is a vairation of the Camel Back. The Hendrickson spring is the most common suspension for us here be it standard spring or ext leaf. Some trucks have rubber block they make your teeth fall out. The Tuff Track made by Freightliner isn't too bad. The cheapest and easiest suspension to work on is a walking beam.
Bob they all have the same gound clearance ,what you provably ment is that the air track has very low clearance betwin the frame and the axles ,thats the only thing
air ride off road is not built to handle the wear and tear the leveler valve will not keep up with the uneven ground and you will wear it out faster i run a highway truck and replace it about once a year and when i am off road i need to lock the axles in to keep moving the valve will not adj fast enough to keep the air bags where they need to be for off road i would stick with what works
Welcome to HEF OD Load! :drinkup
can the air be lowered on all standard fld120 trac/trucks ,or is it installed with dump conversion ?
Welcome to HEF KRiS 660! :drinkup
thanks Countryboy!!
Welcome Kris, Most semi tractors have a dump valve for the air suspension factory installed. They're used quite often while hooking and unhooking from the trailer. An FLD120 tractor could be originally spec'd without a dump valve, but I'd think it rare. Jeff
if it isnt installed how hard would it be to install a dump valve to FLD120 ?
I honestly don't know for sure. I'm guessing it would consist of routing the smaller hard plastic air line(commonly used in air routing where ever movement isn't a factor) from the height control valve in the rear up into the dash, installing a dash valve, and possibly a different style height control valve. That's only a guess though.:beatsme
Pay less road tax here (UK) if you have air suspension.
You want a decent dump truck suspension see if you can retrofit the truck with Freightliner Tuff Trac. Its a rubber ride suspension its far better than air bags it allows the axles to walk over rough terrian. Had experience with it with a 2004 Sterling tandem dump truck walked out of a bad spots like nothing. If you found a wrecked truck in a junk yard you could take the hole rear frame clip with axles and all and put it into the truck you have. I imagine you have 40,000lb high ratio axles which are not very good for a dump truck to start with. Get off road with the truck in soft ground with a load you can hear axle shafts snapping already.
Here you go the best of both worlds http://www1.raydanmfg.com/dotnetnuke/Products/Suspensions/tabid/187/Default.aspx I have never seen one up close but it looks like it would work.
Thats what we call a Meritor system. Our block guy has it on his DAF 8 wheeler (dual steer). It sure beats the hell out of any other system. We run that truck into sites with 51,000 lbs of blocks onboard until its bogged, unload it and then skull drag it out again and its handles it beautifully...very stable, and its amazing how far it will get over rough ground until it does get stuck. Very often I can just stick the mini pushing up his..err......rear end ...and the skid with a long chain and pull him through the soft stuff (it does have diff locks). We had a new Mack cement truck last month that couldn't get halfway into the site that the DAF/Meritor had been in and out of twice without spinning a wheel. *Warning*....the above actions are undertaken by highly skilled trained professionals....cough splutter.....do not try this at home or without expert supervision
I like the tuff trac for the high arch it has and the air can mounting. The cans arent out where they can get covered with black top or knocked off by a big stone.
i've still had no luck sourcing tuff trac, Had sleeper removed and will be shortened this week to fit 17ft dump bed, would of been great if i found it before. HELpPPPP :beatsme Looks like i'll have to buy cut off tandem with hendricks spring and axle specs i need.
Hendrickson Extended leaf walking beam suspension is fine it works it rides fine. The reason why I suggested the Tuff Trac is it does ride a little smoother. I wouldn't delay putting the truck together if you can't find the Tuff Trac. The only Hendrickson suspension you really don't want is the solid mount and the rubber block (pad) suspension. Good stability but man o man if you have any loose teeth they will be on the floor of the truck if you don't have loose teeth they will be. Hendrickson rubber block suspension rides pretty rough especially if you have a light weight box and one out of round tire. Good with a load but empty :eek2 Hendrickson suspension is easy to install prolly alot simpler than Tuff Trac or Chalmers. As for Raydan suspension only one truck here has it and its a Mack. Never driven the truck but have followed behind it with a load and it doesn't lean like a full air ride dump.
It says on one of the pages raydan licenced the system to Meritor for world wide distribution.
Just bought a 88 379 pete and it has the pete leaf air ride not my 1st choice but for the price it will do as a starter truck . Pulled the 5th wheel today and sleeper will come off this week and day cab kit done and then the 24 will have 15ft Daivs dump installed anyway and having a dump vavle installed and we are going to use the 5th wheel slider as the dump valve switch .
Welcome to HEF busdrivernine! :drinkup
Thanks !!! lot of good info here been out of trrucking about 10 years due to cancer been driving school bus last 5 forund this old Pete and knew that I really wanted it lot of recent work done on truck so maybe it will hold together for a couple of years . Think this picture will sow
Pretty sharp looking truck you got there. :thumbsup
I have a 15 foot high side (17 yard) Davis dump on my Western Star. It is a good bed. Good luck with yours.
Thanks! really sad to have to take sleeper off
I couldn't say it any better myself. It's all about application. Up here in New England, guys spec new trucks from the factory to serve a dual purpose. 5th wheels in the winter to haul trailers to survive, and dump bodies in summer to pave with. Mostly all are airride, but not really off-road much paving. There's really no substitute for a Hendrickson or Chalmers suspension once you leave the pavement. The question lies in the percentage of time the truck will be on-road vs. off. Air will certainly increase the longevity of the vehicle's life, keeping shockloads to a minimum. I'm off road constantly with a 46K Pete Airtrac setup with a 55 ton airride lowbed, and I can't move without locking the power divider in once I get in the soft or uneven tourain. Also, I dump the suspension whenever loading/unloading on both truck and trailer, because when unloading especially, you can watch the airbags stretch out to their maximum and the shocks do the same, if you don't dump the air; thus damaging those components prematurely. That's what the chains and/or limiter straps do on newer style suspensions; keep air springs and shocks from stretching all the way, but every one of mine (nylon straps,) have broken so far on this 2007 trailer because of extreme stretching, angles, dropoffs under tires, etc. So, it's a decision based on where, how much, and how often you're going to be I assume.:thumbsup
For a lowbed truck having air ride makes things a little easier breaking the gooseneck on the trailer etc. For a truck that spends 90-100% of the time on the road especially truck tractors a walking beam suspension would make the truck shake apart. With that Pete in the picture above that will be a pretty short wheelbase dump even with the sleeper taken off.
I know for a fact that a couple million of them had walking beam suspensions from Canada alone , and I never saw one "shaken apart"...
Air Ride Sus Air Ride Suspension is pretty much a personal Pref,.....We have 2 Peterbilt one steel body one aluminum and both have no problem going off road, key is, take your time and things won't break, one other key to Air ride Suspension in that application is this - Make sure you have a power lock divider and a Traction Locker, what this does is not only lock the front drives together but locks the front with the rear and off roading problems go away. Always dump your air bags when dumping with a dump truck, doesnt matter if you weigh 73,280lbs or 150,000lbs your chances of upsetting the truck on it side are greater if you don't dump the air! DKinWA - there are all kinds or different Air Ride Suspensions out there, Henrickson, Rockwell, Pete Air Ride, Pete Lowleaf Air Ride, Kenworth does offer a nice 8 Bag Suspension which i think is Hendrickson, Airliner Air ride which is a knock off Hendrickson used in Freightliners. If you typically use your truck for off road use you would be better off with a spring suspension, however the down fall to that is you get the seat pounded in your behind to get from job to job. If you use the truck hauling paving aggregates, stone, sand etc, i would say have air ride. If it was me no matter what the application calls for i would have air ride!! Always remember to drop the air when dumping specially on a lean, trick of the trade is, on a lean leave the lift axle down for stability an dump the drive axles down.
Thanks for all of the replys. My Parking Lot (car hauler / day job) has air ride. My single axle dump has springs, with my equipment getting bigger I'll probably will go with a tandem for my next dump truck. I planon converting a road tractor and most of them have some kind or air ride. Thanks again. dennis
suspensions Its already been said, but I have 2 converted road tractors (air ride) and one with Hendrickson. As stated if youre staying on road most of the time, air ride will ride better, but I dont plan on buying another air ride, they are too much trouble, the converted trucks are not built heavy enough for most off road work and you have to stay on the newer drivers all the time about dumping the bags. As far as spreading rock, with the air ride, Im sure there are people that does it, but I dont, its too scary to raise the loaded bed and pop the tailgate and start moving, I have tried it and body just rocks too much for me. If I had a LoLo tranny, it may work better, but most road tractors dont have LoLo trannies and high geared rears (4:30+) I would rather ride a little harder and use the Henrickson, it works with all applications Just my 2 cents worth
Someone told me that a chalmers suspension is hard on the driver, in a dumptruck running off road...Can anyone comment on this?
dump trucks I have had chambers on a few road tractors, but I have always been told to stay away from chambers (road tractor style) in a dump truck. They dont hold up and they beat you to death
I have a chalmers suspension on my Western Star dump truck. I like it. I do a lot of off roading to job sites and in these situations it is excellent for traction and stability. It rides very smooth when loaded, but empty it certainly isn't "air ride quality". However, with an air ride cab and air ride seat, it doesn't feel that bad.
the newer trucks have a completely different suspension design along with rack and pinion steering. with your truck you won't even come close to that ride. if you want better handling though, try bilstein shocks, replace your pitman and idler arms because they're probably shot. and check your ball joints and tie rod ends, they're probably junk too because of the age. then have it aligned, making sure camber and especially caster are perfect, because caster really has an effect on the steering stability of these trucks.
Hey guys. Im really having suspension/ vibration problems with the 404st. im pretty sure it has the AG-400 Air Glide Suspension. Just wondering does anyone know the correct height for the Height Control Valves?? Yesty only had a light load with 22 sp's (got a 24 pallet 48-ft) the left hand side gauge was readin jus over 3 1/4 and the right hand side was jus under the 3, it was riding real good on the smooth stuff and a few bumps here and there but the vibration jus wont go away!!!...we adjusted the sleeper cab lower but it didnt help!. does the 60 pound check valve stuff up every yr and would a dud HCV be a prob to?
My gusse would be a u-joint on the way out for the vibe prob. Had one that had a couple or three flat needles in it. Had to take them apart to find the bad joint. That mechanic was a heck of a guy, never doubted me. Others took truck for a spin around the block and said it was A-ok. Good old Kenny saved my back. If you have daton style hubs pull wheels and make sure the hubs (spyders) are not bent. Good luck muzy
I would stay away from the KW 8 bag systems. From a mechanics perspective, they really suck to replace the rear diff, especially if you have a loaded dump box on top. If you want air, I would sugggest Pete Air Trac w/ 46k# locking diffs.
I drove a semi dump on air off road! t600 Must dump ride air before you raise the bed. The last company I worked for had a Mack cl700? on air. again it was both on/off road and the ride air had to be dumped before you raised the bed! The problem with that is it changes the geometry on the brakes. Other than that those trucks were equipped with axle lock and wheel lock!
not familiar with this application, but if you have a driveline vibration, I would check the u-joints like Muzy suggested and definitely check the mid-shaft bearing. If its loose in the rubber bearing, its getting ready to come apart and thats not good, when it does that. Make sure all you u-joint yokes are aligned with each other. Good Luck
I have an older model 1985 Western Star tri-xle lowboy tractor that I pull dump with in & out of job site projects. It has 46,000lbs Eaton rears on Neway four bag air ride. I love it with lowboy or dump on / off road. Only problem I experience is it's a day cab with a 260 inch wheels base so it takes a good amount of planning your turning space before getting into a situation that you have to back out of. Off the road on uneven ground I lock the rears automatically but I did that with my Hendrix before breaking loose occurred anyway so no difference to me with AIR. The biggest mistake was one time many years ago while pulling belly dumps I got a deal on a nice truck with reyco suspension which couldn't take off in a dirty parking lot without getting bogged down so wound up adding frame rails with another boogie from under a wrecked air ride tractor which cured that problem..