I am looking at replacing the rear coil conversion on my DII and going back to the factory SLS that my truck was originally fitted with. Before this gets into a discussion of "why would you..." I have just a few questions. I have looked at parts schematics and watched a few videos on converting to coil springs and a video retrofitting but still cant find an answer to my question.
First, after removing the spring and lower spring mounting plate what is left is the mount that is welded to the axle. My question is whether there is a part that needs to be bolted to the axle mount or does the air spring simply sit directly on the mount? To convert to coils you have to bolt the spring plate to the axle housing, but is there a part that is removed before mounting the plate? I just want to make sure I have everything I need at the time I retrofit so I don't have to leave the truck disassembled while I search for missing parts and the time it will take to ship it to me.
Second, on the instruction sheet from the kit from Atlantic British to install the coil conversion there is a mention that you have to go into the ecu to disable the SLS. Is this true, or is the workaround simply plugging the missing fuse back in?

 

In theory the SLS suspension should fit directly into the welded plate provided it has the bayonet slot. The SLABS ECU will require changing back to accommodate the SLS so you'll need a suitable diag tool. You will also need the SLS compressor unit (located on the frame in a box below the drivers seat) and the drier unit which is located in the two lines from the rear but be careful as one line is the air intake. There are also two lever arm height sensors, one on each side, that should be set correctly, again, be careful they are a bit fragile, there is a wiring plug to each of them. Take a look at the RAVE rear suspension section for the various parts and also the control diagram. In timing, I reckon it'll take a full day to reinstate the SLS suspension including the removing the existing springs. Ensure the truck doesn't have any lift or you will need to fit the standard shocks or the SLS airbag will become damaged.

 

 

I recently did the conversion from air to coils. There are no base plates with the air bags -- they simply bayonet onto the mounting points on the axles. There are retaining clips on the tops of the air springs. You will have to unbolt and remove the spring base plates before you can install the bags.
You should check the air lines to make sure they have not been damaged where they will connect to the new bags. If the previous owner did not cap them, they could be full of dirt.
All going well, the job should take no more than an hour or two at the most.

You will need to have a programming device handy when you install the new airbags. There really is no "get the SLS functioning first" because without the bags, the system will probably just show a fault condition if you set the SLABS to air rather than coils, and the compressor will either run continuously, or not run at all.


Oh, and after you reinstall the air springs and get the system working, you will have to calibrate it and set the normal ride height. Only specialised programmer devices can do this step. A Nanocom may be able to do it but I know that a Hawkeye cannot.


The RAVE is the full manual for your truck. There are plenty of links to it all over this forum and the internet in general. It is an essential tool.