have a 93 breakaway that i bought In Boise,ID. model# 9211-3837-30-bs-11b, it has air suspension and had two problems that I am aware of; battery overcharging ( caused by the reference connector on the alternator not making good contact} and the usual short wheelbase complaint of wandering- tire pressure was 110lbs and lowered it to 70 as according to my chart 65 would be correct at gross weight. the ride height seems to be a tad high but will leave that alone for now and put some test miles on it next week. If anyone has more suggestions feel free to speak. It is a nice rig in good to excellent shape needing just a few minor items, low on power but usually not in a great hurry. john

quote:

Originally posted by john canning:
the usual short wheelbase complaint of wandering- tire pressure was 110lbs and lowered it to 70 as according to my chart 65 would be correct at gross weight.

Hi, John, and Welcome.

The two problems could be related.

The first thing I would recommend is weighing all four corners.

Second is getting a weight/pressure chart from the tire manufacturer. (is your chart from Barth or the tire maker, or what?) The pressures on each axle should be set to correspond to the heaviest end of that axle. In other both front tires must have the same pressure, and it must be correct for the heaviest wheel. Same for the back. Some folks add 5 pounds to the factory pressure.

Are all your tires matched? You could put a pair from the rear up front to see if anything changes.

Is the front end tight? Any looseness really talks to you with a long or heavy rear end. (ladies, don't take offense, here)

Congratulations John and thanks for supplying us with your tag info! I see you've been a member for almost 1½ yrs. I guess you finally found your baby. Were you looking for something in that length range?

Just a few more questions please... You're saying that your Breakaway is on a Spartan Air Ride Chassis? What size engine do you have? Could you send us some pictures for our files and one for your avatar?

Looking forward, as are the rest of us, to seeing what your coach looks like...
bill_ny@barthmobile.com

according to my chart for Michilens 65 lbs would be correct at gross weight on both axles, dropping to 70 from 110 seemed like the smart thing to do. haven't had it on the road since dropping air pressure. the front end seems tight, but in my books one of the previous owners was paying attention to the ride and steering the Sheppard box in particular ( did notice that it is somewhat pressure sensitive} . both the spartan and Barth service manuals are deficient although more than most rv people furnish. at 100k there may be need for fresh bushings in the panhard bars and perhaps even a better quality bushing. this seems to be a common complaint with the breakaways and i need to consider that the factory control was not enough. Have had some experience compensation for polar inertia and it will serve me well here. was hoping someone else had forged the path. will get photos later but right now up to the waist in alligators.

quote:

Originally posted by john canning:
according to my chart for Michilens 65 lbs would be correct at gross weight on both axles, dropping to 70 from 110 seemed like the smart thing to do.

Very smart indeed. Some tire shops air up the tires based on the maximum air psi rating, some owners do that too... This could make your coach feel like you're driving around on marbles.

The problem is now, the center section of your tires could be worn down from over inflation. Once you lower the psi, you might get a little bit of plowing in your steering.

quote:

Originally posted by john canning:
was hoping someone else had forged the path.

Someone else may have forged a path already. Part of my questioning was trying to coax more info by asking about your chassis & engine size. You just now said Spartan...

Normally, the Breakaways rode on a Spring Suspension and not an air ride setup like you discussed earlier. The exception was the Gillig Chassis Breakaway that was found in another members coach and he has a 3116 Cat.

I am curious what your tag says about its weight ratings. I do have access to getting chassis info based on a VIN#, if you care to share that, I'll try to research your particular suspension as it doesn't appear to be the norm for most Breakaways.

You have been a member for awhile... but still, seeing that you're a first time poster today, you might not know that I am a Tractor Trailer Truck Mechanic and am familiar with most of the suspension setups found on our coaches. If you wish to bounce some questions around we'll try our best to help out.

quote:

Originally posted by john canning:
...but right now up to the waist in alligators.

Ok... I'll bite. Alligators in Western Colorado?

Perhaps???

I only know of 1 Breakaway that has full air ride suspension. If it is on a Spartan chassis, it is leaf springs with air assist on the rear only.

I have been all thru my '94 Breakaway to try to get it to handle at least so that I am not sawing the wheel constantly. If you have 100K miles on it (and if it is a Spartan chassis) I can assure that the panhard bar on the rear diff will need changing. I also changed out all the leaf spring bushing and shackles. I have gone the gambit of tire pressure changes but, I am running 20K pounds out the door so my tires stay at full 110 on the rear and 100 on the front. I differ from most post about tire pressure, I will always run on the high side and have found the handling on my Breakaway to be better. Further, I run at 70-75 on the freeways all the time and at lower pressures, the tires will heat to a much higher temperature. The most common cause of blow outs is under inflation.

The last remain thing you can do, and again if it is a spartan chassis is to change the caster angle. I added wedge shims to double the original caster and that made a huge difference.

Please confirm what chassis you have and also what rear diff/front axle you have. Most Breakaways have the Dana 80 rear diff and Dana front axle. This seemed to be the standard configuration for the Cummins / 4 speed Allison Breakaway. Mine is a Cummins / 6 speed Allison and have the Eaton diff and Rockport front axle which is rated higher then the earlier Breakaways and some of my efforts would not apply to the earlier chassis. Glad to help if I can.

Welcome!

4s7pt9j10pc008222 it is on a spartan 6000# front and 12000# rear. it has "air glide" mfg by Granning air suspensions, coach was made for California RV according to the body wiring routing prints. yes I also noted that the Barth sheet described the breakaway as spring suspension, but I get the impression that they seldom did the same thing twice. And it already has the track bars installed, it has a manual override on the controls, will try lowering it slightly to check before adjusting, it is at most 1/2" high now. My observations so far indicate a quality chassis all around. just short wheelbase and heavy in the back. Used to have a GMC TDM4515 that was a little that way compared to the 4104s. There are some maneuvering advantages with the shorter wheelbase that make it desirable.thanks, john

quote:

Originally posted by john canning:
I get the impression that they seldom did the same thing twice.

Close the contest.

We have the Understatement Winner for the month.

Every chassis is different, but my gasser tracked way straighter when I went from Michelins to Bridgestone. I just put a later version up front and it wanders even less.

Based on your VIN#... Here is a 72 page Chassis Maintenance Manual for your EC2000 Spartan Chassis. It's in a PDF format.

Spartan Chassis Manual EC 2000/WC 2000

Hope it helps...

Do you know what the part number is on your Granning Air Suspension Axle?

I had just the opposite experience. I put a full new set of Bridgestones on and started on a trip, drove 100 miles, turned around and went back to the installer and told him to get those off! Went back to Michelins and never looked back.

Rear end felt like it was on marbles! Will be on my second set of Michelins next month, 70K miles isn't bad for a set!

John, what engine / trans do you have? I would like to see pictures of that suspension set up when you have time. If the air ride was installed correctly and the track/trailing arm bushings are in good shape, I should track better then leaf springs, might have a bit more tendency to sway in cross winds but tracking should be good.

I have no track bars on mine other then the panhard bar on the rear diff. I have air assist on the rear only, was a crappy install BTW!

I have Wan-Lis on the front and Bridgestones on the back. My 28' has an absurdly short WB (146" - only 2" more than my 19', 1T LWB Ford diesel van). But it drives like it's on rails.

Ed's (MWrench) has been fighting that wandering issue for a long time...

Problem I have is similar, the very short wheel base and a 10' overhang to the rear with the heavy Cummins, Allison 6 speed as a BIG pendulum! Cummins people have told me to expect 'ill handling if the weight distribution is greater then 30% front to rear, mine weighs in at 34% loaded and right at 31% unloaded.

I do like the short wheel base as I get in and out of places where I do the race timing activities.

thanks to all for the info, Bill; the ec200 manual is a real help, and it shows the air suspension as an option, Mine has sheppard steering but that could well be a customer add on as I have all the conversion blueprints. will get back with news and photos in a couple of weeks, john

quote:

Originally posted by Bill N.Y.:

Ok... I'll bite. Alligators in Western Colorado?

Perhaps???

Yep.