'87 Itasca 37RQ, Air Suspension Problem

Rickf1985 · February 08, 2016, 11:56 AM

When you make the ramps to drive up on what I used is 3/4 plywood cut into 24" squares along with 2x8 pressure treated lumber cut to various lengths to give me height and some run up length. If the coach is empty of water and most camping stuff you can use just the outer set of tires to run up on. I tend to use both, it takes more wood but I am going to be under there and I don't want it kicking out side ways. I try to get it up at least 6-8 inches high. What I do is back up to where I want to end up parked and move forward about two feet. Build your platform you will be parked on right at the back of the rear tire. Now pull forward and build the ramp to get up to the platform, this way you are sure that when you are all done the platform is even when you get there. I would back up until the tag is off of the platform and the front axle is on it, this way most of the weight is off of the tag and you can work on it. The other option is to build your platform in two sections, one for the main axle and one for the tag and then once you are in place and well chocked at the front you can slowly Jack up the tag and remove the sections of that platform and lower the tag bit by bit. May actually be better that way but a lot more blocking.

cook elandan · February 10, 2016, 06:54 AM

Rick, sorry but he is not having any issue with the tag axle and allowing it to come back off the ramp will put too much stress on the components. Leaving the tags on the ramp will keep them up and out of the way. He is having issue with the orientation with the air bags that are attached to the drive axle. We just need to help him find out why his air bags are twisting. So he need to look at the three mounting points of the air bag system. The shackles on the leaf springs, which we can see that they are attached. Mounting pads of the air bags, they both appear to be twisted at the same rate, so they look to be ok. Last is the center stabilizing link which we are not able to see by his pic. With the twist in the air bag frame rail, I would say that there is a problem with the link. JMO.

87Itasca · February 10, 2016, 08:11 AM

You're likely right. One of two things has to happen before I can look at it though:

Either it warms up above freezing, so I can do all this outside on the ground, or it dries out enough I can drive this behind my shop to the 11' door back there and drive it in. Neither seem to be happening. N:(

Rickf1985 · February 10, 2016, 10:01 AM

OK, I have been thinking all along that the tag was the problem. D:oH! D:oH! D:oH! D:oH! D:oH!

I just went back through the pictures from Cook and the factory and Itasca and now I have a grasp on the system and how it works. The link that you guys keep referring to is ONLY to stop side to side movement. The bushings in that link will twist fore and aft. They will not like it one bit but they will twist. Looking at the picture from Cook at how that link is bolted in I would be sure to check the attaching bolts to be sure one or both has not broken. It is not designed to go that way. The way the cradle is designed the weight of the coach is carried by the lower cradle through the side links with the leaf springs on top of them. The lower cradle "should" be self centering due to the weight of the bags pushing down and the fulcrum effect from the side links. It appears that the side links have been jammed forward and possibly self tightened the bolts as they did or just plain rusted into that position. You need to get a good bit of the weight off of that axle and deflate the bags and then you should be able to put a ratchet strap between the two axles and pull the lower cradle back into position. I would put a liberal amount of penetrating oil on the pivot point on the drop link and try to loosen that bolt, that would help. Do not pull so hard you start to move the rearward axle forward, it should not take a whole lot of force to get that back into position.

87Itasca · February 23, 2016, 02:11 PM

Hi all,

Over the course of last Sunday, I managed to replace all my tires on the RV. While I was doing this, I had access to the entire system, so I set to work. The center link area was fine. No issues with how it is set up that I can see.

I wound up using a Porta-Jack (what a lifesaver) and with the base sitting on the drive axle, I jacked the cradle back until it was in the proper position. I then tightened the side bolts down with an impact to about 180 ft. lbs to keep it from swinging forward again, unless I bottom out on a stump or something.

Now I seem to have another issue with it, one that likely only I will have an answer to.

It does not air up. None of the valves on the tag axle were messed with while doing any of this, nor while changing the tires. I put 110 PSI in the air tank, and the valves did not open. I was not afraid of damaging the air springs, as the valves would taper off/close the added air to the springs as the rig raised itself. Usually around 60 PSI or so before I would hear the valves open and send air to the springs, but nothing this time. It may simply be at 'ride height", I don't know. The tag axle tires don't tip in at the top like the old ones did before. I did take it for a 15 mile spin or so, and it looked like the bags had a little air in them when I parked the rig, but not enough to noticeably raise the ride height. I think this weekend I will try raising one side of the tag axle up in the air with air in the holding tank, to see if it will add air to that side of the RV. If not, then a problem has arisen somewhere. At least the cradle is where it is supposed to be now; that makes me feel better.

cook elandan · February 23, 2016, 03:32 PM

87, in my pictures, i have 90psi in the air bags. if you want to use as a reference for how high that might inflate. I think that there is a short delay in the linkage with the tag on add/remove air in the bags so that they are not adjusting all the time. Does your tank hold air.

87Itasca · February 23, 2016, 04:02 PM

Before when they were tilted, the bags inflated no problem, the coach just never raised more than an inch or so because of the extreme angle which they were tilted. They do nothing now. The air remains in the tank @110 PSI. I have a slow leak somewhere I need to sort out, but I want to just get the system to function right now. Then I can work on the small leak. The air springs were replaced in 2003, and don't have more than a couple thousand miles on them. There is no air going to them at the moment.

cook elandan · February 23, 2016, 06:09 PM

87, Maybe the PO might have adjusted the valves to a point and now that you have the tires and axle back where they should be the valves are closed. I have disconnected my adjustment rods, they only had a cotter pin to remove and then i moved them by hand, that way i was able to see the movement of the valve and bags. if rusted a little maybe spray with some pb blaster on it.