+- Rawze.com: Rawze's ISX Technical Discussion and more (http://rawze.com/forums)
+-- Forum: Big Truck Technical Discussion... (/forumdisplay.php?fid=1)
+--- Forum: Other truck related Help... (/forumdisplay.php?fid=71)
+--- Thread: air leaf heights (/showthread.php?tid=4702)
air leaf heights - alborz - 06-22-2019
recently I bought a peterbilt 579
it has air track suspension
the height of fifth wheel from ground is 52"
according to Peterbilt. the suspension level from center of axle to bottom of frame should be
11 3/8" where mine is that high.
every truck I look the the top of frame is just as height of the wheels . (22.5" tires.)
I can't find the problem because the trailer height is about
from ground to top of fifth wheel 52"
roof of trailer to fifth wheel 114"
---------------
166" = 13' 10"
RE: air leaf heights - HES - 06-22-2019
52" 5th wheel height is pretty common. Everything else you typed makes absolutely no sense. Are you trying to say your leveling rod is out of adjustment? I thought this forum was ENGLISH ONLY!
RE: air leaf heights - Rawze - 06-23-2019
on most trucks, typically the drive-line between tranny and front diff is straight when they are at the right height?. Otherwise, vibration sets in.
RE: air leaf heights - ynot - 06-23-2019
Where the tires sit on the frame changes depending on the tire size an of course the type of suspension. If the ride height is correct you dont have a problem.
I find it easier to measure off the ground instead of trying to find axle center. Find the loaded radius of your tire from the manufacturer website an add the ride height to it. An that's your measurement from the ground.
Example: ride height 10.5" - loaded radius 19.5" so 30" from ground too bottom of the frame is the proper ride height
RE: air leaf heights - Chamberpains - 06-23-2019
If the OP is concerned that the overall height with the trailer on is low at 13'4" high instead of 13'6" high. Almost every truck on the road, the roof at its highest point measures well under 13'6" high. This is to accommodate many different wheel configurations and 5th wheel heights.
Every truck and trailer manufacturer has to keep the combination height at or under 13'6" high so by design they make them slightly lower than maximum legal limits. This is so they can sell their unit attached to the most everything on the road. Overall height has nothing to do with proper driveline angle and air ride height.
Contact your truck manufacturer with your VIN and ask them what the proper way to measure proper ride height. They are usually universal (the same) but there are also a lot of exceptions.
RE: air leaf heights - alborz - 06-23-2019
(06-23-2019 )Chamberpains Wrote: If the OP is concerned that the overall height with the trailer on is low at 13'4" high instead of 13'6" high. Almost every truck on the road, the roof at its highest point measures well under 13'6" high. This is to accommodate many different wheel configurations and 5th wheel heights.
Every truck and trailer manufacturer has to keep the combination height at or under 13'6" high so by design they make them slightly lower than maximum legal limits. This is so they can sell their unit attached to the most everything on the road. Overall height has nothing to do with proper driveline angle and air ride height.
Contact your truck manufacturer with your VIN and ask them what the proper way to measure proper ride height. They are usually universal (the same) but there are also a lot of exceptions.
Apology to you and everyone
I made a mistake in final calculation the overall height is 13' 10". that is my concern
RE: air leaf heights - Moose - 06-23-2019
The AirLeaf & AirTrac are really for everything other than high cube van/reefer applications. This truck you bought spent its prior life doing anything but. The 11 3/8" unladen ride height is correct. I would NOT suggest lowering it to 'make it work' you WILL have driveline issues later down the line. I've gone through this with the last truck I bought and even with switching to 22.5LP and new low profile 5th wheel I would still be close around 47-48" 5th wheel height. So you're talking about close to $10k worth of modifications to do some occasional work? No, I passed. It works just fine with my end dump, flat, step, tank & anything other than a high cube van.
I'm still on the hunt for a US Mail spec van as they are typically 98" high plate to roof. (My 5th wheel height is 57")
RE: air leaf heights - Nilao - 06-23-2019
Sound to me like the 5th wheel was made for a tanker setup. They have a higher 5th wheel design. I know mine is 48 inches from the ground and with the trailer attached the total height is 13'3".