Coach height

[buck58]

In doing my walk around I’ve noticed my coach rides a little lower on rear passenger side, looks like about a inch to inch & a half....distance between coach and tires... drives fine, no issues ( yet [emoji15]) but it has me wondering ... ideas?? 2018 Aspire

[Gary.Jones]

Well I wonder if this sag is noticed when the coach has been sitting a while without the motor running such as at an RV park, if it is up on jacks, or if you notice this sag when the Cummins is running and you have pulled off the road at a rest stop and the coach has recently been putting miles on itself going down a road? Could be different things given each of those or more.

Could you describe more fully the context you see this?

Please also give us the make, model, and year of your coach (and floor plan although that is unlikely to tell us much).

Gary

[buck58]

2018 Aspire ( with bunk beds) and its absolutely when Cummings is running. As stated when I’m doing my walk around that’s when I noticed it... or when I stop at a rest area for a break & walk around before leaving again..

[brobox]

Ride height is probably out of adjustment. Can you tell by the air gauges is you have an air leak?

[Gary.Jones]

Then that sounds like a ride height issue to me. There is a manifold which controls the air pressure in each of your bags. It is located in the front left side of your coach essentially right up in front of your driver side steer tire. I needed to have that replaced as it was not raising my whole coach up to ride height and sometime was keeping it lower than it should. That was all around. That is not my guess, but if it is not measuring your pressures and maintaining the correct pressure in each of your air lines then you will have a sagging problem.

A more common problem is that you have a hole or leak in that air line or bag. However, in my experience, unless the hole is really big, if the engine is running, then the air compressor is able to keep enough air in the line and the bag to keep it at ride height, but as soon as you turn the Cummins off, then you may begin to see the sag in one area. You can sometimes literally hear the leak. Sometimes its slow and quiet.

Now, this is just deducing from what you say, I would be concerned about your regulator manifold unit. Its expensive! (~ $1,000) so get talking to Entegra and Spartan about it as you want that to get fixed while under warranty. I had mine replaced in Phoenix. Took a knowledgeable coach repair guy (at Massey Diesel) about an hour to pull out the old one and install the new one once Spartan got it to us (overnight). My guess is regardless of which of these possibilities it is, you are going to need to get to a certified Spartan Chassis shop to get this dealt with, so start calling Spartan customer service now. You will most likely talk to Shane, Dave, or Mike there. All of them should be able to get you written up quickly and direct you to a certified Spartan shop they recommend.

Gary

[buck58]

The “ rear air” gauge has never been as high as front gauge...

[buck58]

Coach has about 10k miles on it

[Gary.Jones]

Its not uncommon to have unbalanced front and rear gauges. I have had at least 5 or 6 conversations with Spartan about the differential pressure because mine was the reverse.... lower front than rear and my coach was doing what I consider excessive porpoising on fairly small transitions going down the road. A friend of mine who owns a construction company and a 15 Cornerstone told me that he had that problem and they found that the whole coach was 10-15# lower than it should be. That is adjusted by an overall pressure control valve back in the rear-most compartment on the passenger side. So, they adjusted the whole coach for more pressure. That made the ride better and the porpoising better but then the whole control unit seemed to fail.

The difference front to back is not supposed to be (according to Spartan) more than 8 pounds of difference. However, even talking to Spartan, you get a different maximum difference by talking to different people. Talk to Cummins and Spartan repair shops and they will tell you something different again. There is seemingly no consistency in what you hear from people that should know. However, some difference is not something Spartan's CS people are too concerned about.

Gary

[buck58]

Ok, going to Spartan July 31st... but, traveling now... and what I’ve noticed is the coach rides higher off tires driver rear axle then it does on rear passenger side axle...

[Gary.Jones]

Each bag is separately controlled by the control unit and feeds that area and bag/bags with a separate air line (my understanding), so that narrows the problem down considerably.

Gary

[brobox]

Originally Posted by buck58

The “ rear air” gauge has never been as high as front gauge...

Simple check
Air coach up, write the pressure down for both gauges. Let sit for half an hour then turn the ignition on without starting . If pressure dropped
...air leak if not ride height adjustment

[Gasman 2]

Buck58,
The rear side to side height is controlled by the front 2 air ride height valves. There is only 1 ride height valve in the rear. So check your front side to side to see if it’s off.
You posted you are going to Spartan the 31th. Just some info Western Branch Diesel in Canton, Oh just up I 77 from you can do Spartan work and warranty. I have had good results using them.

[HarleySG]

Originally Posted by buck58

The “ rear air” gauge has never been as high as front gauge...

Mine was like this too, until it was discovered that the Front and Rear gauges were reversed during production. The air lines in the dash to the gauges can be swapped.

Rear should remain around 120psi, unless you're using your brakes.
Front will fluctuate constantly while driving, as air is adjusted with your air bags.

Cheers!

[DonGott]

Is it possible to make this adjustment yourself? During some service work there in Michigan I asked that they adjust the ride height which they did, and they only charged me $60. With that charge I just figured that the job must not be to difficult to do.