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Need some KW rear air suspension info...
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By Krooser - Tuesday, January 18, 2011 3:38 PM
My son is looking at buying a decent '74 K-100... usual NTC350/RTO12513/4.11 SQHD's.

The odd deal is the rear IS a KW as listed on the build tag in the interior... but I've never seen another like it... sorry I don't have any pix (yet) but it has 4 air bags, big cast steel trailing arms and really odd looking MGM aluminum parking brakes that attach to the slack adjusters via long rods... any ideas about this suspension? 

Oh yeah... the other thing is the truck is brown and ivory... with a factory blue and ivory VIT interior... wow!

By 359er - Tuesday, January 18, 2011 3:43 PM
Krooser, Looks like the on in the KW ad.
By Krooser - Tuesday, January 18, 2011 4:00 PM
Wow... sure does... it's still a nice looking truck. The original owner's name is still on the body tag and it was sold new by Rihm kenworth in St. Paul.
By Lmackattack - Tuesday, January 18, 2011 4:07 PM
Sharp looking KW. Miss seeing them on the road but everynow and then one shoots past me going the other way. cant help you on the rears....

By Krooser - Tuesday, January 18, 2011 4:36 PM
Geez... I just added a photo of my old Road Commode to my signature and look how big it turned out!!! BTW that was in 1979 in Blackfoot, ID IIRC... I was loading potatoes.
By newfie-trucker - Tuesday, January 18, 2011 4:41 PM
Nice looking KW  on the KW if it has a long arm from the front the axle to the bags it may be a neway air ride suspension that is on the truck... it looks like a long L shape one piece  from the hanger to the bag
By Krooser - Tuesday, January 18, 2011 4:47 PM
Sez "KW Air" on the body tag... kinda know what Neway you are talking about... I only have two crappy, snow filled pix... I'll try to get some better ones from my kid.
By Robby359 - Tuesday, January 18, 2011 5:28 PM
If it's that old wouldn't it be the 4 bag KW air ride? Does it look like this?
By Krooser - Tuesday, January 18, 2011 5:38 PM
BINGO.... that's it. In what years were these offered? Any comments on how they worked/rode? 
By Robby359 - Tuesday, January 18, 2011 5:43 PM
There's others here that know alot more about the 4 bag on here than I do. The 8 bag Air Glide 100 replaced it sometime in the mid to late 70's. All of my experience is with the 8 bag. I have had very good service from it.
By newfie-trucker - Tuesday, January 18, 2011 5:51 PM
i had some good 8 bag air rides also but also had some that everything in the cab wasnt lashed down was flying around when bobtailing and with loaded trailers ... best air ride i found was the hendricson air ride
By Mark Brubaker - Wednesday, January 19, 2011 12:36 AM
My '73 had that suspension (4 bag).  It needed some bushings at 300,000 (routine).  I rode good most of the time.  It liked to "back slap" ya on some roads,, maybe that was the tanker I was pulling.  It was my first experience with air ride, and I learned real quick to back under a trailer VERY slowly.  You had to give the bag pressure time to adjust (down) or the control rods form the rear end to valve would bend.  There was no manual bag controls.   
By deguitars - Wednesday, January 19, 2011 6:51 AM
Wow! With the VIT package, high back seats & two-tone interior, air ride suspension, etc. that was a pretty special truck back in 1974! The four-bag set up is correct for that year and it's the same that's on my '73. The majority seem to think the 8-bag set up (can) offer better ride quality but the torsion bars give a lot of headaches. The four bag system is pretty simple and offers a decent ride. Plus, at say $100 each would you rather buy four air bags or eight?

Keep us posted on what happens. That one definitely looks like one worth saving.


By Cam - Wednesday, January 19, 2011 8:05 AM
Krooser (1/18/2011)
BINGO.... that's it. In what years were these offered? Any comments on how they worked/rode? 

Kenworth's 4-bag air ride dates back to at least 1961.  It was offered until 1974 model year or thereabouts.  The suspension changed quite a bit over that period.  The earliest ones show metal cuffs around the bags.  These suspensions, at least the early versions, have fairly limited range of suspension travel. 
By Trenton - Wednesday, January 19, 2011 9:46 AM

Is this truck Parked in the Rhibar lot in Sturtevent, WI? If its the one, I drive by it each day on my way to and from work. Looks good  from the highway.

By Krooser - Wednesday, January 19, 2011 11:04 AM
yep its at hribar... thanks for all the info guys...neat ride for sure.
By John Woge - Wednesday, January 19, 2011 12:48 PM
I think '77 was the last year for the 4 bag.

By Krooser - Friday, January 21, 2011 10:40 PM
Looks like my son is going to make an offer on that KW... I'll keep you guys posted on what happens.
By wayne graham - Saturday, January 22, 2011 5:37 AM
Krooser, That looks like a nice truck. The thing you want to be concerned with is the fiberglass dog-house unsnap the cover at back by sleeper and look at the corners of the dog-house. if it is cracked you have a problem as you can no longer get the replacement tunnel and it is nearly impossible to repair and make stay. The suspension whether KW or neway 4 bag is ok and probably the only reason the truck is still around. If you buy it be very glad it was before 8 bag air glide. Should be a nice truck if does not have dog-house problems. That is still the best paint scheme ever for a cab-over and I wish you guys luck. Wayne
By Krooser - Saturday, January 22, 2011 6:15 AM
Thanks for the doghouse tip...

He's looking to have a working truck here so he will look it over pretty good... he runs from the UP to Chicago (mostly) and keeps his other truck running east with a hired gun.

Surprisingly, this KW would replace an '05 379 in his two truck fleet... I bet, at some point, he'll miss that C-16's 600 HP!!!!

By deguitars - Saturday, January 22, 2011 7:33 AM
Wayne is right about checking for cracks in the fiberglass tunnel....the problem is just about all of them are cracked to some extent! Little bitty cracks aren't too worrisome but something that looks like this is cause for concern and further inspection (the rest of the cab on this truck was completely broken as well):

But can still be fixed, it's just a lot of work to prep the fiberglass properly. To really deal with it the foam insulation underneath should be removed and then you can clean the area and lay in new cloth and resin and build the strength back up. I've actually seen tunnels that were broken in half but those were on Aerodynes which have more weight from the roof and extra bunk, etc.

On any K100C (especially 108" cabs like this one) pay particular attention to the floor area around the rear cab mount. They tend to be broken and you'll often see patch panels back there. When KW lengthened the cab they really didn't add any extra support or beef things up to compensate for it and it's a notoriously weak area. Cracks tend to migrate out from under the rear crossmember like this:

Even if you can't see them doesn't mean they aren't there because when you take it all apart it can still look like this:

My theory is that once the floor is compromised the tunnel becomes overstressed and it's just a downward spiral of destruction  from there. So in most cases if the tunnel shows serious cracks there are issues with the floor as well.

Everybody knows I love K100s, but they have some serious weaknesses in the cab structure that you need to be aware of before buying. If it's a restoration project then chances are you'll be dealing with it all anyway but for a working truck it might mean passing or failing an inspection or something. I do happen to know where there's an original fiberglass tunnel for sale but you really don't want to remove one because it's no fun at all!

Please keep us posted, it sure is a nice looking survivor, and my favorite paint scheme too!

By wayne graham - Saturday, January 22, 2011 7:42 AM
David, Thank you for explaining that way better than i could. Your picture definitely showed the famous crack point. After it was too late KW came out with a fix for those cabs but like you said who wants to change a tunnel and start over. Wayne
By Krooser - Saturday, January 29, 2011 1:21 PM
We reinforced several K100's that had cracked floors above the front hinges... 
By 1955 kw bullnose - Sunday, May 08, 2011 10:54 AM
Wile on the topic of this early kw air ride, I just picked up a set and am wondering if anyone has, or can get good pics of the shock mounts that bolt on the outside of the frame.

By deguitars - Sunday, May 08, 2011 12:43 PM
Good timing...this photo from Cam's recent slide presentation post shows what you need pretty well.

By the way, where did you get the mud flaps on your truck in the background?

By 1955 kw bullnose - Sunday, May 08, 2011 12:48 PM
I saw that pic a couple days ago, just not sure how far that mount sticks out. I orderd them from kw, they are the newer kw logo not the old one, A kw dealer might have them in stock, or you can order them from them.
By John_Costley - Sunday, May 08, 2011 1:09 PM

Here is what I have.

The ones titled 4bag and 4bagrear are from an Aussie member named Steve, a mid to late '70s W900 that he had shipped over from the USA.Second generation, outboard mount shocks.Hasnt been on the forums in quite awhile.

The 923,924 1966 brochure page shows first gen, inboard shocks.The Kwsusp shows 2nd gen, inboard mounted shocks.The 4-bag is from a '65 maintenance manual, first gen, inboard shocks.The one titled late 4-bag is second gen, inboard shocks. John 
By Wolfcreek_Steve - Sunday, May 08, 2011 1:20 PM
Looking at the various pics and drawings, the lower mount came in both orientations. On yours the shocks are mounted inside the frame at the top and I dont see a clear picture of what the mount looks like.
By John_Costley - Sunday, May 08, 2011 1:45 PM
Wolfcreek_Steve (5/8/2011)
Looking at the various pics and drawings, the lower mount came in both orientations. On yours the shocks are mounted inside the frame at the top and I dont see a clear picture of what the mount looks like.


If I remember right the mounts are mounted to a crossmember, studs facing rearward, simular to the way they are mounted on the KW torsion bar suspension, but turned around.I dont think the mounts are mounted on the inside of the rails with studs facing across at each other like Pete airleaf or KW 8 bag.John
By 1955 kw bullnose - Sunday, May 08, 2011 2:52 PM
John, Mine looks just like the one in the 1966 brochure, I was told they were mounted on the outside of the frame, it came off a 67 peterbilt, might of been easyer to put them on the outside then to a crossmember if it wasnt in the right spot to mount a shock to them.
By John_Costley - Sunday, May 08, 2011 3:12 PM

As long as the spacing is right on the end of youre arms so that shocks run true up and down without rubbing the rails it shouldnt matter if you mount them outboard.They might actually work better that way anyway.John
By 1955 kw bullnose - Sunday, May 08, 2011 4:33 PM
Im thinking they will go on the outside, Much easyer to make up something for the outside thne it is to move cross members. Thanks for that info though. Do you have a bigger photo or extra copy of that 1966 brochure? would be kinda neat to have that to show the people that ask what it is. I have already had one guy say he has never seen or heard of that early air ride when we stoped at the truck museum in Brooks on the way back.
By John_Costley - Monday, May 09, 2011 12:01 AM

I saved that after someone else posted it, cant remember who.I cropped it but it didnt help much.John
By John Woge - Monday, May 09, 2011 12:54 PM

I have the manual that shows it.....when I get time I'll scan the section.

 I'm a little surprised to see your frame brackets are still the original type....all four of ours have been broke and replaced with the later style.


By 1955 kw bullnose - Monday, May 09, 2011 1:34 PM
I looked and dont see any cracks on them, will see if there is some hiding under the paint though, hope not. It would be great if you could scan them John W.
By John Woge - Monday, May 16, 2011 10:35 AM

 I'll post these here for anyone your PM and if you can't get them off here...I'll print them and send 'em to you.....we're out of black ink at the moment..


Don't know why they ain't in order...07 is the first
By 1955 kw bullnose - Monday, May 16, 2011 1:42 PM
Thanks John. I tryed printing them out, they are good enough for me, i set the printer to print it slower and it did ok sence there isnt alot of colors.