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Bindu56 
Samba Member
Joined: May 14, 2011
Posts: 21
Location: CA
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 Posted: Fri Jun 01, 2018 4:30 pm Post subject: Rear Anti Roll Bar Homemade |
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I recently installed the 25mm Anti-roll bar from T3 with the HD end links and it is an awesome addition to my van. The improvement to ride, cornering and overall stability are amazing.
But that left me with a spare 21mm roll bar and end links from my 82 Westy/diesel/Subaru and I wanted to finish the upgrade with a rear ARB. I bought the Addco kit but I didn't like anything about it, never installed it, and figured there must be a better way. I came across the Vanagon factory 'above the frame' ARB in one of the forums and it made a lot of sense. A few have made similar setups using front ARBs so thought I'd give it a try. It turned out to be amazingly easy and works better than I ever thought possible. It is the frosting on the cake after the T3 install. I am amazed at how fast I can corner now in stable comfort with neutral handling.
All that's needed is two pieces of angle iron for brackets for the rotational bushings (unless you can figure out a way to mount them on top of the frame) and drilling two holes in each trailing arm, two in the frame on each side to mount the brackets. The brackets have to mount as far forward on each frame rail as you can go for the bar to clear the springs. The brackets mount on the outside of the frame rails and the bar will be tight in the bushing. The hard part is drilling the front frame hole for the bracket-the frame rail is in the way-requires a short drill bit and angle drill.
Drill out the existing holes in the trailing arm top and bottom. The bottom hole allows you to insert an extension to Tighten the nuts inside the arm. Size is 1/2" or just big enough to fit the steel sleeves. For bushings and hardware I used the Powerflex and SS hardware from T3--perfect for this use.
After 1k miles I see no downside to this setup at all. It's one of the easier jobs I've done on my van.
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hdenter
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Joined: October 14, 2008
Posts: 2940
Location: San Luis Obispo, CA
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| Posted: Fri Jun 01, 2018 4:56 pm Post subject: Re: Rear Anti Roll Bar Homemade |
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That's a nice write up. My only concern with that design is whether or not the sheet metal of the rear control arm will stand up to having so much pressure being applied to one small point. With every side to side sway, significant force will be alternately up and down to that thin sheet metal. As a box, that arm is strong. But will the metal fatigue around that hole...? I have a White Line rear bar and can appreciate that it isn't too attractive to have it hanging low. But at the ends it is bolted to the shock mounts, a very solid spot.
Hans
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'79 triple white convertible bug
'84 sunroof vanagon
'85 weekender |
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Bindu56
Samba Member
Joined: May 14, 2011
Posts: 21
Location: CA
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| Posted: Fri Jun 01, 2018 8:25 pm Post subject: Re: Rear Anti Roll Bar Homemade |
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I don't think it is a problem. The metal is not that thin--it's about 1/16" thick and very hard-not easy to drill. Plus the bushings top and bottom spread out the stresses (there is the same bushing underneath, in case that wasn't obvious.) I took it apart after 1K miles and there is no obvious wear on the bushing or anywhere--looks like new.
_________________
1982 Vanagon Westy/diesel/SVX/VW 5spd GT 4th/5th
89 Vanagon tintop w GoWesty 2.2--Sold
2012 Touareg Hybrid 3.0 Supercharged V6 333 hp |
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Zeitgeist 13
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Joined: March 05, 2009
Posts: 12167
Location: Port Manteau
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| Posted: Fri Jun 01, 2018 10:23 pm Post subject: Re: Rear Anti Roll Bar Homemade |
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...
Last edited by Zeitgeist 13 on Sat Jun 02, 2018 5:11 am; edited 1 time in total |
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vanis13
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Joined: August 15, 2010
Posts: 4396
Location: ABQ NM USA.... Except when not
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| Posted: Fri Jun 01, 2018 11:05 pm Post subject: Re: Rear Anti Roll Bar Homemade |
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FYI - looks like he's connected to the FRAME rail not the inclined under-seat body panel...that is why he needed the 90 deg angle steel.
_________________
83.5 Westy with Subaru 2.5, 4 spd manual, center seat, COLD A/C on 134a!, Winter camp heated with an Espar B4 gasoline furnace
www.SuperVanagon.com - some stuff I make |
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D Clymer
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Joined: December 22, 2005
Posts: 2986
Location: Issaquah, WA
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| Posted: Fri Jun 01, 2018 11:07 pm Post subject: Re: Rear Anti Roll Bar Homemade |
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My only reservation about fitting an ARB to the rear of a Vanagon is the potential loss of articulation of the rear trailing arms. In stock form, Vanagons already have poor rear suspension travel in the "droop" direction and lose traction very quickly on any surfaces that unload one of the rear wheels. Does it seem like the rear suspension articulation is significantly affected by the addition of the swaybar?
Nice job with the fabrication work. Looks like you had a clear vision from the get-go on how to make it all come together. |
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Multiman mv
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Joined: January 24, 2017
Posts: 988
Location: Martha's Vineyard, Ma
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| Posted: Sat Jun 02, 2018 4:20 am Post subject: Re: Rear Anti Roll Bar Homemade |
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Interesting idea. I have a rear addco bar sitting in my shop for about two years. I never installed it because of how low it mounts. I’d be interested to see how your setup performs and holds up over time. It looks like you’ve figured out a rugged setup. I guess if you’re not doing a ton of off-roading on rutted out roads, the articulation issue won’t be a factor. I love the addition of my front bar. Totally transformative in terms of cornering. I’ve always pondered adding a rear bar. Nice job figuring out your setup!
Last edited by Multiman mv on Sun Jun 03, 2018 11:41 am; edited 1 time in total |
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T3 Pilot
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Joined: January 10, 2011
Posts: 1509
Location: Deep South of the Great White North
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| Posted: Sat Jun 02, 2018 5:22 am Post subject: Re: Rear Anti Roll Bar Homemade |
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For reference, here is a link to the factory installation diagram of the rear anti roll bar:
http://www.oemepc.com/vw/part_single/catalog/vw/ma...980/lang/e
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1988 Vanagon
The most important part in every vehicle is the nut behind the wheel...... |
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MarkWard
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Joined: February 09, 2005
Posts: 18753
Location: Retired South Florida
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| Posted: Sat Jun 02, 2018 6:28 am Post subject: Re: Rear Anti Roll Bar Homemade |
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| Good use of parts on hand. How did you access the nut on the drop link? |
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Bindu56
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Joined: May 14, 2011
Posts: 21
Location: CA
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| Posted: Sat Jun 02, 2018 10:39 am Post subject: Re: Rear Anti Roll Bar Homemade |
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Thanks for the responses guys.
MarkWard: The nut can be accessed through the opening for the axle--plenty of room to thread on and off and install the bushing and washer, though it is a test of manual dexterity! It could be tightened with an open or box end wrench through the opening but is tedious. Its far easier to drill the corresponding hole under the Arm big enough for a ratchet extension. The holes do not line up exactly so it is necessary to use a u-joint extension on the socket to the get correct purchase on the nut.
D Clymer: I have seen this objection before and don't think it is true that it limits articulation but can't prove it. I have tried lifting one wheel with a jack under the trailing arm but it just lifts the whole rear of van off the floor when it gets to about half compression. The other wheel remains at full extension at that point. That was true before I installed the ARB as well. I have been thinking about a way to test this but haven't come up with any bright ideas. I have done a small amount of mild off-roading with the ARB and do not notice any difference.
As to the strength issue: I would point out that the spring sits directly on the trailing arm, on the same metal as the ARB connection. While there is a minor reinforcement under it, it is more of a general strengthening and there is no direct strengthening or reinforcement of the spring contact area. There is no visible wear where the spring contacts, leading to the conclusion that the metal is very hard and strong. The stresses imposed by the ARB are very minor compared to the stresses of the spring. I see no need for concern or reinforcement.
_________________
1982 Vanagon Westy/diesel/SVX/VW 5spd GT 4th/5th
89 Vanagon tintop w GoWesty 2.2--Sold
2012 Touareg Hybrid 3.0 Supercharged V6 333 hp |
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Bindu56
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Joined: May 14, 2011
Posts: 21
Location: CA
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| Posted: Tue Feb 25, 2025 9:16 pm Post subject: Re: Rear Anti Roll Bar Homemade |
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Update--seven years later and about 40K miles, this project is still going strong. There is no cracking in the trailing arm, and the installation has been trouble-free.
_________________
1982 Vanagon Westy/diesel/SVX/VW 5spd GT 4th/5th
89 Vanagon tintop w GoWesty 2.2--Sold
2012 Touareg Hybrid 3.0 Supercharged V6 333 hp |
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Rorke
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Joined: August 04, 2016
Posts: 275
Location: Traverse City, MI
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| Posted: Wed Feb 26, 2025 8:19 am Post subject: Re: Rear Anti Roll Bar Homemade |
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This is cool.
Glad it has held up.
Thanks again for the details. |
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Crooked Designer
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Joined: March 22, 2018
Posts: 573
Location: Chicago, IL
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| Posted: Wed Feb 26, 2025 8:43 am Post subject: Re: Rear Anti Roll Bar Homemade |
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Bad ass.. I kept my old ARB as well and plan to do this upgrade. Mrs. Crooked needs all the stability we can get (pun completely intended).
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'85 Westy full camper, Subaru 2.5L, 5 speed SubiGears + 5speedbus shifter kit |
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metahacker
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Joined: May 26, 2010
Posts: 892
Location: san.diego
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| Posted: Wed Feb 26, 2025 9:18 am Post subject: Re: Rear Anti Roll Bar Homemade |
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ya gotta love the 2-for-1 of putting on the super nice T3T front bar and getting to re-use the old front one in the back. resourcefulness at it's best
that new T3T rear bar sure looks sweet though :) |
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Phishman068
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Joined: February 19, 2007
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Location: Pittsburgh PA (ish)
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dhaavers
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Joined: March 19, 2010
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Location: NE MN (tinyurl.com/dhaaverslocation)
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| Posted: Wed Feb 26, 2025 9:44 am Post subject: Re: Rear Anti Roll Bar Homemade |
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| metahacker wrote: |
| ya gotta love the 2-for-1 of putting on the super nice T3T front bar and getting to re-use the old front one in the back… |
| Phishman068 wrote: |
T3 should make a kit for exactly that!
Buy their front HD setup and a retrofit kit to place the unused stock sway bar as a rear sway bar! |
THIS! 
- Dave
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86 White Wolfsburg Westy Weekender
"The WonderVan"
<EDITED TO PROTECT INNOCENT PIXELS> |
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Christopher Schimke
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Joined: August 03, 2005
Posts: 5526
Location: PNW
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| Posted: Wed Feb 26, 2025 12:53 pm Post subject: Re: Rear Anti Roll Bar Homemade |
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| Phishman068 wrote: |
T3 should make a kit for exactly that!
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Before I say anything about the quote above, I want to make it clear that I am all for people doing things their own way. I very much appreciate people who tackle DIY projects like this. I'm also fully aware that people have their own ideas of how things should be and that often there is more than one way to get a job done. So, to the OP, what I say below is NOT a reflection of you or your work. It's just my opinion on the rear anti-roll bar situation.
First, yes, I'm aware that VW used a front anti-roll bar on the rear of certain T3 models. However, the bar they used was 19mm (the least stiff bar of all the T3 anti-roll bars) and they only used it on the Ambulance models. Using a bit of logic and assumption, I'm pretty confident that they installed the 19mm bar on the rear to help stabilize the body of the van to minimize the impact of body sway and roll on the patient inside the van, and not because they intended to run the van through the slalom course.
And yes, I am completely aware that Eric runs a 21mm front bar on the rear of his race Bus. However, he also has a huge front anti-roll bar. His front anti-roll bar is 2.4 times stiffer than our 25mm front anti-roll bar, and over 5.2 times stiffer than a stock 21mm bar. In other words, we can't really use his van for any kind of comparison.
Understanding the impact of running a rear anti-roll bar that is too stiff is important. But in order to explain that, you first have to understand what an anti-roll bar does for the T3 platform.
In relation to our vans (or the whole T3 platform), anti-roll bars have the following effects:
Reduce body roll
Affects cornering traction in terms of front/rear understeer and oversteer characteristics
A rear anti-roll bar also affects forward traction
It's important to understand that an anti-roll bar ties the left and right wheels together. When a van takes a right hand corner, the outside wheel is pushed upward in its travel range. With an anti-roll bar in place, the bar tries to push the inside wheel upward as well. To what degree the bar pushes the inside wheel upward depends on the amount of cornering and the stiffness of the anti-roll bar.
When the anti-roll bar pushes the inside wheel upward, that tire loses some level of traction. Yes, the outside tire does see more pressure exerted into the ground which increases traction slightly, but the amount of additional traction is much less than the traction lost to the ground on the inside tire. This is why adding a stiff anti-roll bar can reduce cornering traction at that end of the van. Reducing cornering traction leads to oversteer or understeer.
In the case of the rear anti-roll bar, reducing traction to the inside rear tire reduces both cornering traction and forward traction.
Getting back to the matter at hand, adding a rear anti-roll bar to the T3 platform needs careful consideration since forward traction must be considered as well as the potential to create an oversteer condition. Most average drivers do not handle an oversteer condition very well. That is why most road vehicles are designed to understeer.
In my mind, losing some forward traction is mostly an annoyance, but creating an oversteer condition could be very dangerous. For an ambulance application or a race Bus application, it's not that big of a deal, but for a street van in the hands of a driver who has no idea how to handle an oversteer condition, the results could be dangerous or deadly. And that is one of the biggest reasons why I chose NOT to use the front anti-roll bar on the rear of a T3. This applies mostly to the 21mm bar, but even the 19mm bar is too stiff for the rear. To put this in perspective, our rear anti-roll bar kit is about 5 times softer (in terms of torsional stiffness) than a 19mm front bar. We did this 100% on purpose to add a bit of rear roll stiffness without adding any rear oversteer.
There are also reasons that have nothing to do with handling. For one, while some vans have lots of room, many vans have A/C lines and electrical that occupy space right where the left side bar mount needs to live. The chance of the bar rubbing through those items is too high for those applications.
Also, I'm not a fan of putting bolts through the frame rail without having support (like sleeves) inside the rail to allow the bolts to be tightened properly. Without inner support, you can only tighten the bolts so much before the rail starts to be crushed. And without the bolts being tightened properly, there is a real chance that the holes could wallow out and/or crack over a long period of time. While this last point may seem minor to some, it's a real enough possibility that I'm not willing to take that chance. Maybe on a personal van, but definitely not on a customer's.
*EDIT*
I wanted to add that when considering understeer/oversteer, it doesn't just come into play when you're driving hard through the twisties. It also applies to emergency/evasive maneuvers, going around a corner that may be slightly slick, getting on the throttle too early in a slick corner, etc. In other words, handling characteristics come into play every time you drive the van, so even though it may seem like oversteer/understeer may not apply, it definitely does.
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"Sometimes you have to build a box to think outside of." - Bruce (not Springsteen)
*Custom wheel hardware for Audi/VW, Porsche and Mercedes wheels - Urethane Suspension Bushings*
T3Technique.com or contact me at [email protected] |
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Crooked Designer
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Joined: March 22, 2018
Posts: 573
Location: Chicago, IL
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| Posted: Wed Feb 26, 2025 1:37 pm Post subject: Re: Rear Anti Roll Bar Homemade |
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I wasn't 100% sure what the oversteer hazard was, so looked it up. Figured that might be the case for others reading Christopher's post.
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'85 Westy full camper, Subaru 2.5L, 5 speed SubiGears + 5speedbus shifter kit |
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Ahwahnee
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Joined: June 05, 2010
Posts: 10222
Location: Mt Lemmon, AZ
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| Posted: Wed Feb 26, 2025 1:46 pm Post subject: Re: Rear Anti Roll Bar Homemade |
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Rallyists have a saying:
Oversteer scares the passenger, understeer scares the driver. |
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Christopher Schimke
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Joined: August 03, 2005
Posts: 5526
Location: PNW
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| Posted: Wed Feb 26, 2025 2:05 pm Post subject: Re: Rear Anti Roll Bar Homemade |
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| Ahwahnee wrote: |
Rallyists have a saying:
Oversteer scares the passenger, understeer scares the driver. |
Yes, I hear what you are saying, but most Vanagon drivers are not rally drivers, nor do many have the skills to deal with an oversteer situation.
_________________
"Sometimes you have to build a box to think outside of." - Bruce (not Springsteen)
*Custom wheel hardware for Audi/VW, Porsche and Mercedes wheels - Urethane Suspension Bushings*
T3Technique.com or contact me at [email protected] |
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