TheSamba.com :: View topic

Sat Jun 22, 2013 11:40 am

With the recent threads on shocks and airbags I thought I’d offer a look at what I’ve done. I have been using this set-up for more than 3 years now so I am confident that it works for me and addresses the issue I wanted to fix. YMMV as they say, so decide for yourself if this is a good idea or not.

I installed Gabriel Hijacker Air Shocks on the rear of my 84 Westy.

I used a separately purchased kit to be able to air up the shocks individually.

The air line runs to a valve that is mounted in a convenient hole already present on the lip of the fender behind the wheel.

I did this solely to be able to level the van left-to-right, either when unladen or fully packed for a trip. Like most, my Westy was lower on the driver’s side without an assist in place. The result is a level van that can be easily adjusted prior to travel or on the road. The hot pink tape on the shock body is so I can easily tell with a look if one or both shocks need more pressure. The actual adjustment is done with a pressure gauge and measuring stick – I do this about as often (and at the same time) as checking tire pressure.

A concern with such an arrangement is the additional stress it may place on the shock mounts so I kept an eye on the top mounts…

and the bottom mounts…

I see no evidence of any problem with either.

This is obviously not a solution for bad springs nor appropriate for jacking the rear way high whether for off-road clearance or just bling. My driving is mostly on paved roads and never in true off-road conditions. I only use air shocks to level and thus there is no need to go crazy with air pressure, lift or the additional stiffness that would come with that.

Bottom line, the van sits level, the ride suits me and after three years it still rides fine. I make no warranty or claims as to the suitability of this for others, merely offer it as ‘what I did that worked for me’.

Sat Jun 22, 2013 12:05 pm

Nicely done Ahwahnee!

I have had the Monroe version of air shocks on my rig for about two seasons of driving. Ski in winter. Camp/tour in summer.

I use them for load assist (leveling, as well... a symptom of loading in my case) and have had some serious loads in my van. :D

No issues, and I find them to be a better solution in terms of load assist than the Monroe Sensatrac coilo-vers (which I ran similarly for 2 yrs prior)... if for no other reason than the adjustability.

I agree these (or the coil-overs in my case) do not solve the problems of old worn out springs.. but they will buy time with old worn springs if you are hemming and hawing on a true fix to bad springs. I do not recommend it.. but did it myself until I found satisfactory springs.

Nice pics, too!

Sat Jun 22, 2013 3:55 pm

Hi,

Looks like a nice addition. I have been considering this mod as I periodically carry my motorcycle on the back of the van via a Hitch mounted carrier. The motorcycle weighs about 240 lbs & while the van handles okay, it tends to give it an extra "droop" in the rear.

Do you happen to have the part number of the shock you are using?

Thanks in advance,
Bill

Sat Jun 22, 2013 5:23 pm

Bills85Westy wrote: Hi,

Do you happen to have the part number of the shock you are using?

Thanks in advance,
Bill

There is a link to the Gabrial shock in the first post.

The exact shock I used is the MaxAir model no. MA758.
However, this particular shock is a longer travel version than OEM shocks.. and it is not a great application for stock height vans using OEM CVs. (The CV is not quite up to that extended angle range of operation)
And the shock may bottom before you bump stop does.. NOT good.

A better fit for your van might be the MA768.
That's 12" compressed, and 18.5 extended. Close to OEM.
(you can check your current shock lengths by compressing them and getting a measure that way)

That MA768 shock lists a LS26 and LS28 mount, top and bottom. You may need to shim out the narrower mount with a fender washer or 2... But the mounts on the van and the swing arm are both "clamp" style and are intended to be compressed in tension snugly around the shock bushing sleeve. There is some give to the mounts on the van, so you have wiggle room.

(In my fitment I chose to shave the shock bushing sleeve down a bit to fit better. The bushing sleeve was a 1/16" or so on the bigger side.

You have 12mm mounting bolts (not 1/2").. although they are pretty darn close.. the 1/2" mount version actually allows a bit of movement. I prefer the 12mm.

Here is a link to Monroe's fitment sheets so you can verify what I have said here..
http://www.monroe.com/assets/downloads/english/08_MountingLengthSheet.pdf

You will also want to check your shock mounts and bolts.. Although the mounts will not take up a whole lot of force over stock.. the added resistance as you pump up airshocks DOEs increase forces some. As long as you don't go curb hopping or dune jumping you should be fine (given the mounts and bolts are OK and rustfree)

FWIW.. the Gabrials are likely a very safe bet, too. Equal, if not better.
(I don't mean to stomp all over Ahwahnee's post, :wink: )

Sat Jun 22, 2013 6:08 pm

Nice!

I've used air shocks on vehicles with no problems except for the inconvenience of them leaking down. Eventually you find yourself adding air more often as the seals weaken.

I solved that with an Air-Lift compressor and in cab leveling system. No more paying for air at gas stations...lol

Check it out.

http://www.4wheelparts.com/Towing/Load-Controller-...7Aodm0EAbQ

Sun Jun 23, 2013 10:16 am

j_dirge wrote: Bills85Westy wrote: Hi,

Do you happen to have the part number of the shock you are using?

Thanks in advance,
Bill

There is a link to the Gabrial shock in the first post.

The exact shock I used is the MaxAir model no. MA758.
However, this particular shock is a longer travel version than OEM shocks.. and it is not a great application for stock height vans using OEM CVs. (The CV is not quite up to that extended angle range of operation)
And the shock may bottom before you bump stop does.. NOT good.

A better fit for your van might be the MA768.
That's 12" compressed, and 18.5 extended. Close to OEM.
(you can check your current shock lengths by compressing them and getting a measure that way)

That MA768 shock lists a LS26 and LS28 mount, top and bottom. You may need to shim out the narrower mount with a fender washer or 2... But the mounts on the van and the swing arm are both "clamp" style and are intended to be compressed in tension snugly around the shock bushing sleeve. There is some give to the mounts on the van, so you have wiggle room.

(In my fitment I chose to shave the shock bushing sleeve down a bit to fit better. The bushing sleeve was a 1/16" or so on the bigger side.

You have 12mm mounting bolts (not 1/2").. although they are pretty darn close.. the 1/2" mount version actually allows a bit of movement. I prefer the 12mm.

Here is a link to Monroe's fitment sheets so you can verify what I have said here..
http://www.monroe.com/assets/downloads/english/08_MountingLengthSheet.pdf

You will also want to check your shock mounts and bolts.. Although the mounts will not take up a whole lot of force over stock.. the added resistance as you pump up airshocks DOEs increase forces some. As long as you don't go curb hopping or dune jumping you should be fine (given the mounts and bolts are OK and rustfree)

FWIW.. the Gabrials are likely a very safe bet, too. Equal, if not better.
(I don't mean to stomp all over Ahwahnee's post, :wink: )

Great summary! Thanks. My next project!

Tue Dec 31, 2013 1:17 pm

My initial reaction to the Gabriel air-adjust shocks:
First off, in front I am running the Moogs with Koni adjstables set to one of their stiffest settings. In the rear I have a good pair of westy springs, 1" of spacer and was running some old KYBs. A decent match front-to-back, but the KYBs were a tad harsh and I wanted adjustables for towing and loads.

The Gabriels went in fairly easily though I wrestled with replacing the bushing and sleeves to the correct diameter. It seems the shocks operate independently from the air bags, meaning the dampening and control shouldn't (in theory) be different at varying heights (inlflation). The shocks seem to be fine in terms ride comfort and rebound. Nothing special but certainly don't feel mismatched with my front.

They are rated for 25-200lbs of pressure. At 100lbs (the most I've tried) the rear of the van sits at 18.5" (fender to wheel center) and makes for a dramatic rake to the front's 17.25" height. It also felt a bit top heavy in the handling, but not terrible. Dropping the bags to 26lbs brings the rear down to 17.5"....just the slightest rake and handling is noticeably improved.

Here's my question: I don't understand spring physics very well, but it would seem that if air shocks are used to lift the van at all, then the "resting pressure" on the springs would be changed and would subsequently change the behavior of the springs, no?

Tue Dec 31, 2013 1:56 pm

That's correct.
The shock acts mostly independent of the air bag.

I run mine (Monroes) at the min 25 lbs.. I only add air if the rear sags, from level, under loads.. And it take 300lbs before my van begins to squat appreciably, in the rear.

I would not add more air if it increases rake. What is your rake when the van is empty?

The physics of the springs as they relate to the air bag:
As you lift the rear or allow it to sag.. you move center of gravity of te entire van, fore or aft.
With rake, you increase load slightly to front springs.. when sagged you increase load slightly to rear springs
A level van is, typically, preferred..

So, if you add air to bring the van back to level, you maintain loads evenly on the corners again, per intended design of vehicle..

Lets say you have to increase air pressure to 45 lbs to keep the van level with the particular load you have for that given day..

You will need to know the added load's weight over the rear axle to determine how much load is removed from the rear spring and how much moves to the air bag as the air bag is employed to level the van... In other words how much load carrying is being aided by the shock.

In simplest terms. (numbers for explanation, only)
The van weighs 5000lbs.
Each corner takes 1/4 of that = 1250lbs.
Add 300 lbs over the rear axle and it takes 45 lbs of air to bring the van level.
You have increased the rear corner "weight" or load by about 150 lbs.. (its actually less because some of that is taken up in the front.)

Now. That air bag is taking up that difference.. which means that approx. 15% of the rear quarter load is moved onto the air bag/shock.

Of course this increases/decreases as you drive and take up impacts/bumps..
But 15% is a reasonable estimate for what you've asked that air bag/shock to do.

The spring continues to support its regular 1250 lbs and doing the vast majority of the work.. the shock/air bag is supporting the added 150lb ..

Mon Apr 21, 2014 12:30 pm

Tested the gabriels a bit this weekend with a cargo rack. Probably had about 250+ lbs (rack + hitch adapter + gear) on the back, including a spare wheel/tire after a puncture. The trunk space was also pretty loaded, though not too heavy. I experimented with the pressure in the shocks, and I must say I'm now really appreciating this mod. Generally, I find the 25lbs minimum a bit stiff for driving unloaded around town, but it feels great on the highway and open roads.

When I added the cargo rack and gear I brought the pressure up to 40lbs., which was too much. Completely eliminated the heavy rear end feeling (wallowing up front) but too stiff. Stiffer than unloaded 25lbs. Van was raked and I could feel it in my seat. Then I reduced the pressure to roughly 27 and it was a more comfortable ride, but it came with some front end wallow . Then increased to 35 lbs and it felt perfect. I definitely would not be as excited to use this cargo carrier if I didn't have these shocks. Huge difference.

BTW, these cargo carriers are a game changer for me. So nice to get some of the big bulky or dirty items out of the van, and a great place to put the trash on the way out. Also nice as an in-camp platform for cooking, gear, etc.

here's where I put my fill valve. Used the existing hole and the space behind allows for extra tubing etc.

Mon Apr 21, 2014 12:59 pm

I've run these in the back of my long bed F150 for years and LOVE them. It never crossed my mind that there was an application for Westfalia's, but it really makes sense. I'll be picking up a pair in the near future since my Westy needs new shocks anyway.

Mon Apr 21, 2014 2:29 pm

FYI - this is the kit I used in addition to the shocks to be able to control the air pressure independently left & right:

Gabriel 140656 Air Shock Hose Kit

Sat Apr 26, 2014 5:10 pm

So I've got the wrong bushing at the bottom. OEM sleeve and bolt I believe, but wrong bushing. Not sure if this is because I transferred the previous bushing and shouldn't have, or didn't transfer it, or what...but clearly this aint right.

Having trouble finding a suitable "hat-style" replacement on the web. Willing to switch over to 1/2" bolt/sleeve if necessary. But just not finding the obvious solution. Any ideas/sources? What should I do in the meantime...stack washers on both sides or something? thanks

Sat Apr 26, 2014 5:45 pm

Steelhead wrote: So I've got the wrong bushing at the bottom. OEM sleeve and bolt I believe, but wrong bushing. Not sure if this is because I transferred the previous bushing and shouldn't have, or didn't transfer it, or what...but clearly this aint right.

Having trouble finding a suitable "hat-style" replacement on the web. Willing to switch over to 1/2" bolt/sleeve if necessary. But just not finding the obvious solution. Any ideas/sources? What should I do in the meantime...stack washers on both sides or something? thanks

Hey D!
I just saw your email on this, too.

Energy Suspension makes several different size "hourglass" shaped bushings..
Do a search on ebay.
They come as a single piece.. or as a double or split 2 piece bushing.
There is bound to be a size that fits this application and the hourglass shape will keep the shock eyelet centered on the bushing.

Measure the inside diameter of the shock eyelet.. and the distance between the tangs (shock mount on swing arm..

We can fix this.

Sat Apr 26, 2014 6:01 pm

j_dirge wrote:
Energy Suspension makes several different size "hourglass" shaped bushings..
Do a search on ebay.
They come as a single piece.. or as a double or split 2 piece bushing.
There is bound to be a size that fits this application and the hourglass shape will keep the shock eyelet centered on the bushing.

Measure the inside diameter of the shock eyelet.. and the distance between the tangs (shock mount on swing arm..

We can fix this.

thanks, I was wondering about the hourglass shaped ones...wasn't sure if those were only for shocks that had hourglass shaped eyelets(?).

Sat Apr 26, 2014 6:31 pm

Steelhead wrote: j_dirge wrote:
Energy Suspension makes several different size "hourglass" shaped bushings..
Do a search on ebay.
They come as a single piece.. or as a double or split 2 piece bushing.
There is bound to be a size that fits this application and the hourglass shape will keep the shock eyelet centered on the bushing.

Measure the inside diameter of the shock eyelet.. and the distance between the tangs (shock mount on swing arm..

We can fix this.

thanks, I was wondering about the hourglass shaped ones...wasn't sure if those were only for shocks that had hourglass shaped eyelets(?).
They can be used if they fit snug... or better yet, I am seeing some 2 piece types that have flanges on them.. similar to what T3 technique sells as 2 piece for the control arms.
I am looking for Energy's master list.. I had it bookmarked but have lost track of it.

Here:
http://www.energysuspensionparts.com/table-catalog.asp

Sat Apr 26, 2014 6:34 pm

Shouldn't I be looking for something like this?
http://www.ebay.com/itm/2-Universal-Shock-Loops-w-...mp;vxp=mtr

Sat Apr 26, 2014 6:44 pm

Steelhead wrote: Shouldn't I be looking for something like this?
http://www.ebay.com/itm/2-Universal-Shock-Loops-w-...mp;vxp=mtr
I don't think you need the inner sleeve...
How about these?
http://www.energysuspensionparts.com/proddetail.asp?prod=9.9176
You can cut them down lengthwise to fit.. Have to measure the shock eye diameter, though..
Or with sleeves, here:
http://www.energysuspensionparts.com/proddetail.asp?prod=19601

Sat Apr 26, 2014 7:01 pm

Those might work though I need to fill up a lot of space with flanges of the bushings. Just under one inch in total (1/2"per side).

you know...I think I ended up with wrong Gabriels. Comparing the width of my eyelet to Awhanee's above, It seems I have narrower eyelet, which probably lead to me hacking upon install. Wondering if maybe I should start over with correct gabriels with wider eyelet.

Sat Apr 26, 2014 7:17 pm

Steelhead wrote: Those might work though I need to fill up a lot of space with flanges of the bushings. Just under one inch in total (1/2"per side).

You want the flanges of the bushing up against the eye so it does not slide around.. then maybe fill up the area on either side with fender washers.
"Hacky".. yes.

Quote: you know...I think I ended up with wrong Gabriels. Comparing the width of my eyelet to Awhanee's above, It seems I have narrower eyelet, which probably lead to me hacking upon install. Wondering if maybe I should start over with correct gabriels with wider eyelet.

Compare model numbers.. If not the same, I'd also be concerned about length extended and compression.. check your order, too. A mistake in filling the order maybe.. gets you new ones.

[code]How about drilling out a pair of tall bump stops and trimming them down to right length? Nice long cones. will keep the shock eye centered and can customize size. hacky but might work well.[/quote]
Not sure which bump stops you are thinking of... but necessity is the mother of invention!

Mon May 26, 2014 9:41 am

In case anyone is wondering about the load leveling capability of these shocks. The bike below is 250+lbs and rack itself is at least 50lbs. I was also hauling at least 500lbs of gear, water, etc in the center of the van. The air shocks had ~70lbs of pressure in them, though I probably could've gone to 100. The ride/handling was fine and felt safe enough. I did put a lot of weight in the passenger foot well and directly behind front wheels in order act as ballast.

On my unladen (and relatively light) van, these shocks are a just a bit stiff/jarring around town, but with any load of 200lbs or more that get ride improves dramatically and matches the koni/moog front nicely. I'm seriously considering adding a big battery bank under the rear bench in order to help with the ride (and have lots of juice for fridge etc).