My new truck will be

been just reading your thread, but I feel the exact opposite about air-ride front axle. I would never buy a truck without it.

 

Don't order Kenworth of any kind...or paccar product...same think...I didn't install fs2500 yet, because all my problems...I have new problem...my truck is trying to kill me...this is the story...I have very annoying rattle under my bad...ok no problem, I will found what it is...looking to fix rattle problem in last two months/with dealer to/and no success...so two days ago i lift my bad up, looking for few more fixes for rattle...my good luck i wasn't too deep into bunk, and suddenly both shock absorbers total failure...boom...I have entire bad on my back...both shock absorbers failure in once...amazing...just pure bad luck...and i still have rattle...yesterday on avgust 3 i was driving on hwy 54 east bound texas...outside temperature 74...suddenly black skyes and and bad weather, and again my bad luck, start huge ICE storm...yes ice in August...I didn't se nothing like that in my life...my truck is damaged on left side from few thousand ice hits...and everything was done in ten minutes...just bad luck ,bad place in wrong time...my cb still is on and and off...my brake pedal feels very weird, so everything is getting worst...tomorrow, service again, what else i could do...very sad, very sad...this is the worst truck in human history...worst piece of crap ane garbage...no more words...

 

2014

2014 579; 3 axle; 80" double bunk high roof sleeper; 242" w/b w 3/8 frame, isx 550/2050 w/ rt side undercab emissions package; mxp 18spd UltrashiftPlus; 14x rears w/ rear locker; 3.08 rears (Wanted 2.47's to cruise in direct but factory wouldn't approve w/ high torque engine, 3.08's were as low numerically as they'd go); HD drive lines; HD cooling pkg; 2 speed fan drive; low air leaf rear suspension; front air leaf w/ dual ride control valves; air discs on steers; 8.6" drums on drives; 10 aluminum wheels w/ lo pro 22.5 Michelin Energy on rear, XZA 3+ on steer; NavPlus; single vertical stack; 6 wheel abs/w/traction control; twin 150's; all synthetics; full fairings to back of sleeper; extended warranties on everything. Build sheet is 16 pages long, so there's a bunch of other stuff. Eaton is supposed to be programming w/ low rpm progressive shifting software.

 

Oh yeah, it also has a wide track steer axle for absolute tightest turning radius and dual-trac rear hubs so I can run singles w/o bearing problems should I want to do that in future.

 

With all these bad luck you put me on a serious head scratching. I cant believe its happening in such a bad manner. I wish you resolve all these problems asap.

 

TULY007: When you are pulling a grade, how low w/ your Ultra let the engine rpms go b4 it initiates a down shift? I want to make sure mine will go at least to 1250 at full power before it shifts. That should let the next gear engage at 1425 or so which w/ my engine spec is roughly 2000 ft lbs.

 

If your front air leaf doesn't have dual control valves I'd try that first. If you still aren't happy, check this website: http://www.donvel.com/steeraxle.htm Since you already have the air bags, all you'd need are what they call motion control valves. I've not used them, but they've been around for a while and might help you. I think what they are is an cone-shape affair inside the valves and they operate like the old anti-reversion headers from the muscle car days. Truck hits bump, air bag pressure rises and some is forced through the large hole in the cone back into the system, but when the pressure drops, air has to come back through the small end of the cone and the timing is very different before equilibrium or originl air back pressure is reached.

 

That should have been "... original air bag pressure is reached."

 

OK, pupeperson....what u'll be hauling with this baby...cause with this set up u'll do it all ..good for 75mph and strong climbing with its torque....
Minw is 3.55 RR 485isx 1650tq...and the ultra+ box goes down to 1200 rpm before skipping 1 gear downshifting, when climbing i think depends on the setup.....but is easily reprogrammed to ur taste after u get it, as im told and read a few articles about the ultra....
If donot do oversize/weight dont think u need 18 sp except if none of the 13 come for big torque...

 

Btw pupe whats the empty build sheet weight on her...i have just one air front valve on right side...ill ceck that info about updating....
Reason for me to say about 18 sp is that this engines are very quick on revving and the box will skip gears 2 /3 at the time ....but hey just me.....congrats and good luck....and what color did u get.....