Handling the Handling (Rear Anti-Roll Bar)

Today, I return from a break with a one-off posting. I remain distracted with non-post-worthy stuff, but I did this work on the bus recently, so I thought I'd post about it. This post covers my reasoning and efforts to install a rear anti-roll bar (called a sway-bar in the US). I could regale you with all kinds of scientific study and test drives leading me to doing this. The reality is, I bought the EMPI kit last Summer ($180US delivered) and it has been sitting in a somewhat large box in my somewhat small garage since. In a way, I installed it because I needed the room. I mean, we just can't keep tripping over, or piling things on, this box, besides I paid $180 for it. That's not a small sum to just not use.

Where Were We

Recall the drive to Leisureland (See Leisureland Road Report) and the drive to/from 4Peaks in the Summer of 2021 (See 4Peaks 2021 Road Report). The wind and passing trucks buffeted the bus, making handling extremely difficult. I had to slow way down on the drive east through the central Oregon desert simply because I could not keep the bus under reliable control. That was scary. I started with the simple: stiffen the adjustable shocks (See Handling the Handling - Shock Adjustment). This helped, but on our next drive out the US-26 for Hapy's birthday, the passing trucks and crosswind still impacted the handling. Consider this quote from that test drive: "he held the road. I needed both hands on the wheel, but it was not (a) white-knuckle experience." <- that is not exactly the description of a solid, love-this-handling suspension that you would want to take for long trips.

I want to see if I could make it better... besides, I have the kit, I need the room on my garage floor and after two months I really need to get my hands on a car with some tools.

Rear Anti-Roll / Sway Bar

CIP1 image has the
bar upside down

Back when I first considered the handling issue, thought through the causes, and was performing my research, I found some other bus owners with similar wind-sheer challenges. These folks were posting on threads talking about the pro/con of a rear anti-roll (sway) bar. RAtwell conducted experiments a few years ago, and most feedback on the interweb is consistent with his findings: the rear bar is great on highways, in windy conditions, going mostly straight, especially when you are burdened with some weight (like camping equipment). Sounds spot-on for my issue, right? Well, there are no upsides without downsides.

For these bars, the downsides include a tendency for over steer (vehicle turns more than turn of steering wheel would imply) while cornering, especially in city driving, and the rear suspension is not as independent so you will feel more bumps. So.. the bar is great on long trips, but around town, where there are speed bumps, sharp turns and potholes, they may make things worse. One point that I found especially interesting is where the long road trip meets city driving: freeway off-ramps. Since you are often pairing rapid deceleration with an increasingly sharp turn, the influence of the rear bar could come into play. This feedback, however, is the opposite of what both CIP1 and EMPI says about these bars. Taken from the CIP1 site: "...These sway bars provide the handling demanded by the enthusiast driver. They help to control body sway and help road adhesion under hard cornering...".

clean rear bar example

So, what about installing a bar and just disconnecting it when you're not doing the loaded-on-the-highway thing? I thought about that. The Jeep and off-road crowd will disconnect one or both anti-roll bars when they go crawling. The fancy new ones allow you to do it from the driver seat with a button. Old-skool involves rolling under your rig and disconnecting the ends, and zip-tying it out of the way. On an old bus, there obviously is not a push-button install option. The bar, however, is not a simple straight bar either. As you can see from the picture on the right, here, that I nabbed from "Goodhand77" who posted it on theSamba, it runs from the mount points at the wheels forward (front is front) and inward to the frame rails. It then dips in the center to create space around the transaxle. So, if you were to disconnect the ends and try to rotate the bar up, the lower center section would rotate up towards the transaxle. More importantly, it approaches the suspension arms. If you just disconnect the ends and let it hang there, it may interfere with the wheel movement. So that doesn't seem like a safe option. In the end, I concluded that the rear sway bar is an either/or: either it is installed or it is sitting in your garage. I got one last Summer and have tried the sitting in your garage option. The handling was unaffected, but the room in my garage was and is, with no value back. So, we're installing it.

Rear Shock Mount Tie-In

instructions

This is the fun part, when we get to put hands on bus. The install is not mentally difficult, but does require boring 4 holes into your beloved, and it can be time-consuming. I have attached an image of the install instructions. The directions start with putting your bus up on ramps (not stands) so you have more room while the suspension is under standard load. They suggest suspending the bar temporarily while you install it, but I didn't. I just let it rest on the ground while I did the rear connections. We remove the lower bolts on the rear shocks, add an "L" bracket, and thread the nut back through. I thought about reversing the bolt so it pointed inwards, but decided that the VW engineers probably had it like this for a reason. Still, when I want to adjust the shocks, it will be a hassle. Into the "L" bracket goes a bolt with a series of bushings and washers, with the bar and the nut completing what looks like a hardware version of a Dagwood sandwich. The bolt through the middle is barely long enough to make the reach, so I had to compress the sandwich while getting the nut to catch a thread. One side was, of course, harder than the other. Slightly longer bolts (provided are 5-1/4") would have saved me an hour of wrestling with the Dagwood, with washer and nut sent flying with each failed attempt. Once the threading caught, I snugged the sandwich together with a few turns on the ratchet: just enough to set the stack and the locknut plastic, without compressing the bushings at all.

 

Frame Mount

p-side frame mount

With the bar connected at the ends, the frame mounts can be test-fit, marked, drilled and mounted. While test-fitting, verify the marked holes with the size of the u-bolt; since these holes are for the u-bolt to go through, this is super-important. I hit the center-points of the marked holes with a hammer and drift so the drill-bit wouldn't wander. My drill bits are getting worn, so the cutting of the holes took many cycles of progressively larger bits to reach the 3/8" target. Once bored out to 3/8", I set the bar up in place and could tell that the inner lip of the frame was going to prevent the bar from mounting flush, so I removed a curved section of the lip with my angle grinder to allow the bar (with the mounting plate in place) to rest against the flat part of the frame. The instructions mention filing, but it would take all day with a file. I shot the area with a quick pass of spray paint to prevent rust. Finally, we're ready to thread the u-bolt through. This is just an exercise in patience, unless one set of holes was not distanced correctly. Fortunately, my triple-checking during the measure-mark step avoided an issue here. The instructions say to put one nut on and to thread the u-bolt through. The nut is to prevent you from losing the u-bolt into the frame. Because of the tight tolerance, the nut needs to be near the tip of the u-bolt, but then it could fall off... leading to the u-bolt disappearing into the frame. Yep, this happened to me on the driver side, but I was able to coax it out with a thin-bladed screwdriver... and more patience.

Tighten Up

rear anti-roll bar installed

Once the u-bolts are dangled down from the frame, use one nut on the u-bolt as you work part of the mount on the other, starting with the base plate. Carefully, push the bar up and then wiggle the u-bolt through the clamp. Once both bolts are through , the nuts are threaded on, tighten the nuts down, shifting from one nut to the other until it is not going to work itself loose while you're doing the other side. Repeat on the other side, and then torque both mounts down. Last, return to the lower shock mounts and tighten everything down. I had left the lower mounts and the sway bar mounts loosely threaded so I had maximum maneuverability while the front was assembled.

Start to end, this took me a few of hours, but only because I move slowly, it was 5*C (just over 40*F) when I did it and my dulling drill bits were a challenge. I probably could have moved faster if I really wanted to as well, but even in the cold, it was really nice to love on Hapy for a little while. Since Hapy is off the road for the winter, and his front seats are out (See Hapy Seating), I was unable to execute a test drive. Still, I expect the handling to be much stiffer, and my garage has gained about 3 cubic feet of floor-space. Win-win. Soon, we will hit the highway for a suspension test.

 

That's it for today. I intend to complete the seat install next, but finding time when the puppy isn't underfoot is the barrier. He needs constant oversight or he will eat something he's not supposed to. He's like a goat that way. He has no interest in being, and it has been too cold (4*C) to have him, tied up outside with me while I work for more than 20 minutes. And, he's too wiggly to just hang out inside the bus while I work on him. So, until I can solve for him, thanks for following along. I will disappear for a while again. If I get the chance to do something, I'll post on it-