Tinkering With Removing Rear Shocks with AHC

[OG 91 LC]

First and foremost my newbiness doesn't really know how the AHC works in concert with the front and rear shocks. I know that I have some control of the softness and stiffness on the shocks by the control of my center console with a range of comfort to sport.

I had a chance today to tinker and study the truck and to check out various components underneath the truck. So I got to thinking of the rear shocks. I eventually want to replace them. I have read that they are a PITA to remove because of the lack of space to work. Some have drilled a hole from inside the rear cabin to get to the nuts and bolts necessary to remove the shocks; something I don't want to do.

So this morning I played around with the idea of how I would remove the nuts and bolts necessary to remove the shocks.

Here are a few first questions. What does this line do for my shock? I mean. How does it work to go from comfort to sport mode? Do I need to do anything with the AHC system(disconnect or disconnect battery) before I remove? And is this line under any kind of pressure?

I decided to play around with how I would get to these nuts and bolts. I got my truck on High mode using the AHC. I don't have many tools, but this is what I used. I used my small ratchet with a 12mm socket. I also used my 6" extension with a 12mm deep socket.

So here is the lay of the land. This is looking from underneath the truck on the rear passenger side.

There are 2 two bolts and one nut that are a PITA to remove. Two bolts holding the line and one nut holding the shock, bushings, and spacers.

The bolt facing towards the front of the truck is the one that's more challenging than the others.

 

[OG 91 LC]

So here's how I started to remove the bolts holding the line.

I got underneath the truck and I squeezed my small ratchet with the 12mm socket onto the bolt closes to the rear of the truck.

I was able to loosen the bolt quite easily. To get a better handle on ratcheting I used my 6" extension and my second 12mm socket like this.

My attempt was not to remove the bolt, but to find a method to loosen the bolt and tighten it back up. This worked pretty easy.

Now to get to the second bolt facing the front.

 

[OG 91 LC]

Now I was working from undernear the front of the rear passenger wheel. I once again took my small ratchet and 12mm socket and maneuvered the ratchet to get to the bolt. It took a bit of feeling the bolt to finally get the socket to sit on the bolt. Here's how it looked from underneath.

Here's the handle of my ratchet already seated on that rear bolt.

And here's how the small ratchet looks from above seated on the bolt.

Again. I was able to to loosen up the bolt quite easily. I was able to get a better grip by using the extension again like this.

Again. My attempt was not to remove the bolt, but to find a way to loosen it up and to tighten it back up. This took a bit more time then the other bolt, but was a success. No need to drill a hole

Now if I were going to remove the rear shocks I would jack the rear up and do the above procedure.

Fellas. What is the size of the nut holding the shock, bushings, and spacers?

Hope this helps some of you.

 

[uHu]

Lots of threads in here on removing the shock, and on how the AHC works.
The nut is 22 mm, and that's the one giving problems, sometimes. Yours has no rust, so there's probably no problem getting it off.
BTW, if you had unscrewed those 2 bolts a bit more, you would have had an ahc fluid shower, and the car would have come down by 4 inches.

If you study the ahc litterature a bit, you'll find that the shocks are not really shocks. Just hydraulic rams which are controlled and damped by the actuators sitting on the frame rail close to each wheel (to which the accumulator (globe, gas spring) is attached).

 

[OG 91 LC]

Cool. Thanks for the info. I will do more searching.

 

[flintknapper]

You didn't mention whether or not you put jack stands under your truck but IF you didn't....DON'T get underneath it again when working on the AHC without supporting the vehicle.

If any part of the unit should fail...or if you disconnect any of the lines (as previously mentioned) the system can/will drop all the way to the bump stops. You don't want to be underneath it when that happens. The fluid shower you receive will be the least of your worries.

IF you did use jack stands, good....just keep the above in mind. Please be careful.

Flint.

 

[PADDO]

Darwin Award material.

Edited to explain why you shouldn't tinker with a hydraulic system supporting a vehicle's sprung weight.

SAFETY WARNING: In AHC vehicles the sprung weight is supported by mechanical springs (rear coils and torsion bars) and hydraulic pressure - neither provide sufficient lift to independently support the vehicle's sprung weight. Undoing a pressurized line to a shock actuator that is supporting the vehicle's weight will result in the sudden depressurization of the hydraulic circuit and the collapse of the suspension, the rear in this case, down to the next mechanical support level, the bump stops.

 

[OG 91 LC]

Roger that.

Just to be very clear. My attempt was not to take off the bolts. It was to show how I would get to them and a method. I got a feel of how easy I could get to them. I didn't even rotate that bolt more than an 1/8 or less of a turn.

Thanks for pointing out the safety issues and concerns.