Volkswagen Vanagon 4x4 Conversion.

[vwhammer]

Well as usual Metcalf, you read my mind.
I am actually even looking at some stock control arms that might work in my situation and would leave that sort of thing open to future upgrades.
I may build or modify an upper arm so there is some adjustability but I had not thought about an adjustable frame mount.
Space will be pretty tight but I will see what I can come up with
That reminds me, don't suppose you, or anyone else for that matter, would mind measuring their 80 series rear lower control arm and telling me how long they are?

 

[Metcalf]

Well as usual Metcalf, you read my mind.
I am actually even looking at some stock control arms that might work in my situation and would leave that sort of thing open to future upgrades.
I may build or modify an upper arm so there is some adjustability but I had not thought about an adjustable frame mount.
Space will be pretty tight but I will see what I can come up with
That reminds me, don't suppose you, or anyone else for that matter, would mind measuring their 80 series rear lower control arm and telling me how long they are?

The factory rear FJ80 lower arms are approx 27.5" long. Personally. the hang down bracket for the rear lower arms is one of the things I don't like about the 80 chassis. It will be a bit of a rock magnet. Even with a 40" tire is looks like it will be in the way. I would much rather have a smooth transition from the belly of the frame to the rear arm, but on this chassis it would totally mess with the geometry.

 

[vwhammer]

Hmmmm.
Well as I iron out the geometry for my suspension I am left with a choice that I am having difficulty with.
It's a simple question but I struggle with the answer.
Do I run rubber joints or one of the many multi-piece, rebuildable joints that are on the market? (google Johnny joint for those that don't know what I am talking about)

The rubber will better isolate road noise and vibration and will be virtually maintenance free until they are worn out and need replaced.
Generally, however, the rubber joints will flex less than a similarly sized multi-piece joint and replacing a rubber joint in the field can be difficult should the need arise. (which probably won't be that often)

The "Johnny joints" will likely flex more easily and are easily field serviceable but also require more maintenance in that you need to tighten them as they wear and they will need greased regularly.
They will likely also transmit more road vibes. (don't know. never used them)

Durability and serviceability are at the top of my list during my build so you may see why I am struggling here.
It seems rubber may be more durable but the Johnny joints are more serviceable.
I am also not going for 2 feet of suspension travel so perhaps the flex will not matter much.

Then, to make things even harder there are the Duroflex joints from Metalcloak that have an easily replaced rubber flex joint in a rebuildable format much like the Johnny joints.
This seems like the answer but I don't know a lot of people that have used them and it appears that this would be the most costly option.

I will make a decision eventually but I figured I would take advantage of the forum platform to gather any input that anyone might have.

 

[bknudtsen]

Johnny Joint at the axle side and rubber at the frame side.

 

[brianjwilson]

I installed metal cloak control arms on my JK and liked them. Quiet, smooth, and I could actually feel the axles moving more freely on the trail. Really kind of a win win win as long as the cost is reasonable.

If the Vanagon made a bunch of torque I might be inclined to recommend heim joints on the axle ends but I think I would keep the ends all the same for simplicity sake.

 

[Metcalf]

Keep it simple.

Find a common OEM bushing to use throughout the control arms. Jeep TJ lower bushings would be just fine in my opinion. Build the arms so that you can press them in and out yourself with a simple tool in the parking lot. Carry a spare or two.

I would build a jig to make all the lower arms the same length and non-adjustable.

Make the upper arms adjustable on the vehicle without having to drop off the arm out of the suspension. Use some kind of double RH/LH adjuster.
I don't like jam nuts if I can help it, use a pinch bolt system.

Cheers.

 

[vwhammer]

Tiny update
I pretty much have my suspension geometry sorted and I think I have come to a conclusion as far as what joints to use where.
I took Metcalf's advice and looked into the TJ control arm bushings.
After a little research it seems that Jeep used these bushings on many of their vehicles.
They were used on Cherokees, Grand Cherokees, The TJ obviously and even some of the full size dodge trucks.
Heck even the Liberty has these on them somewhere.
It seems that Clevite is the brand that many people trust and they can be had for $10 to $15 a piece depending on where you shop.
Heck I am pretty sure if you went the super cheap route you can get a pair from rockauto for like $15.
That beats the crap out of the $35 to $40 a piece for the Land Cruiser bushings I was using previously.

It just so happens that Rusty's off road sells a forged threaded tube end that accepts the TJ lower control arm bushing rubber bushings.

I also found a place that sells pre-machined sleeves that I can weld into anything that accept this bushing for only slightly more than it would cost for me to by the material and machine the sleeves myself.
This pretty much made the choice a no brainer.
So I will be running TJ bushings all over.
This will consist of a fixed lower control arm with the TJ bushings at each end.
The upper will run the threaded bushing end at one end and a fixed bushing at the other.
The adjustable end of the upper will be fitted with a double adjuster from Poly Performance.
I actually used these same double adjusters for my links on my radius arm set up so I know what I am getting into there.
By my careful guesstimations I will be able to change my upper control arm length by plus or minus 1 inch.(maybe a bit more but I probably won't need it)
Couple this with 3 different mounting points at the frame end of the upper link and I should be able to get varying degrees of anti-squat/anti-dive from about 80% to 130%
This will likely allow all the tuning that I will need for both front and rear suspensions.

Anyway, while I wait on resources (money) to build all of my suspension bits I decided it was time to scavenge my drivetrain from my donor.
Here's the dusty old lump of 2.2 liter fury.

Got it all set up outside.

This is my first time removing the engine and trans from a Subaru with an auto trans so there were a few snags.
I originally intended to take it out as one piece and perhaps I could have but after looking at clearance between the trans tunnel and trans and the engine/suspension cross-member and trans I decided that separating them would be the best option.
However, to remove the torque converter bolts apparently you have to remove the intake manifold to access the hole to get to said bolts.
You can see the hole in this pic

So obviously I took the intake off and go the bolts loose.
I did not work on it as long as I intended so that's about all the further (farther) I made it.
Pretty much all I need to do now is unbolt the engine from the trans and unbolt the exhaust from the heads and yank that bish out.
Then I can work on the trans.

This is an important step because I need to get this set up mocked up in the van to see how my rear axle clears every thing.
After that I can send the info off to Front Range (AKA Diamond axle) and have them build me a fancy new rear axle to match the front.

I should have the engine and trans out tomorrow and I can work on locating it in the van over the next couple days.

Until then...

 

[Metcalf]

Couple this with 3 different mounting points at the frame end of the upper link and I should be able to get varying degrees of anti-squat/anti-dive from about 80% to 130%

I'd lower that to 50-100 or even 50-80

Generally those numbers are based off of sprung CoG also so you have to guess at that to a degree....

The front end will tolerate a bit more AD typically. It may help keep the front end from feeling like it is squating under hard braking, which could be interesting with the van setup.

Rear end AS even close to 100% will be generally pretty unnerving if the vehicle is climbing if it starts jacking under load, especially with a higher sprung CoG like your base vehicle may have.

 

[vwhammer]

@Metcalf
Would you really go as low 50% AS?
For the rear I never really intended to go over 100% and generally assumed that I would end up well below 100%.
Pretty much all I assumed would happen with anything over 100% would be wheel hop while trying to climb anything steep that might have a little traction.
I have never actually plugged in any numbers for any of the popular stock suspension designs out there but I would assume most of them are well under 100% as far as anti-squat goes.

I will agree I am pretty much wingin' it on the CoG.
This is the only real thing that is wrecking my numbers.
Naturally if the vehicle was totally assembled you can find the CoG pretty easily.
However, this is not a luxury that I have so I just have to wing it.
I have a feeling (maybe hoping) that my CoG might be a little lower than I am expecting because my engine and trans are not all that heavy but my axles and transfer case are and my fuel, batteries and a couple other heavy things will be placed lower than the engines CoG.

I do have the option to actually build in three positions on the frame mount for the lower link as well.
This, combined with an upper link that is adjustable in both length and the mounting point on the frame, will give me much more range of AS/AD adjustability.

I was shooting for a front AD number pretty close to 100% simply to keep the front end from diving too much under braking.
The Vanagon is unique in the respect that it is a rear engine van with the cab forward design.
believe it or not the weight distribution front to rear on the Vanagon is very near 50/50.
With this in mind I don't need to go too high with AD numbers so some range maybe slightly above 100% to something around 80% would be best.

I guess time will tell.

 

[Metcalf]

@Metcalf
Would you really go as low 50% AS?
For the rear I never really intended to go over 100% and generally assumed that I would end up well below 100%.
Pretty much all I assumed would happen with anything over 100% would be wheel hop while trying to climb anything steep that might have a little traction.
I have never actually plugged in any numbers for any of the popular stock suspension designs out there but I would assume most of them are well under 100% as far as anti-squat goes.

I will agree I am pretty much wingin' it on the CoG.
This is the only real thing that is wrecking my numbers.
Naturally if the vehicle was totally assembled you can find the CoG pretty easily.
However, this is not a luxury that I have so I just have to wing it.
I have a feeling (maybe hoping) that my CoG might be a little lower than I am expecting because my engine and trans are not all that heavy but my axles and transfer case are and my fuel, batteries and a couple other heavy things will be placed lower than the engines CoG.

I do have the option to actually build in three positions on the frame mount for the lower link as well.
This, combined with an upper link that is adjustable in both length and the mounting point on the frame, will give me much more range of AS/AD adjustability.

I was shooting for a front AD number pretty close to 100% simply to keep the front end from diving too much under braking.
The Vanagon is unique in the respect that it is a rear engine van with the cab forward design.
believe it or not the weight distribution front to rear on the Vanagon is very near 50/50.
With this in mind I don't need to go too high with AD numbers so some range maybe slightly above 100% to something around 80% would be best.

I guess time will tell.

Yup, I would go that low. I'd rather have a bit too low AS/AD than too high generally. The numbers also tend to change, get higher, when you are climbing and the CoG is transfering to the rear and up. I think starting a little soft is better than too much. With too much AS, the rear end will JACK up loading the tires and making the suspension less compliant, inducing a bit more torque roll, etc. The hop you mention will happen, and that is hard on parts and unsettles the vehicle in a dynamic situation. Not good overall.

Front suspension. Having NO brake dive is bad too. Basically you can overload the tire contact patch which can cause brake hop. With bigger tires it isn't too concerning, but I would build in some adjustment on the upper frame side arms to help tune things since you are guessing for these numbers in relation to SPRUNG CoG (the calcs should use the sprung CoG, not total vehicle CoG)

Keep the lower arms as level to the ground plane as possible. Try and get as much separation on the axle side as you can package to increase joint life and lower the chance of torque wrap. Build in some adjustment points for the frame side uppers.

The thing you can get right without any guessing is roll centers, roll axis for each axle, and roll slope for both combined. I'll try and type some stuff up for that later.

You should also be thinking about overall shock and how much uptravel from ride height you can package. Rough rules. Maintain spring preload at full droop no matter what. Find out how much uptravel you can get from your desired ride height, times that by two basically for overall shock travel. Try and package as much uptravel in from a low stance as you can. This will bring up spring rates and help with body roll a bit. With the van setup, I would be thinking about where to pre-package a front and rear sway bar from the start also.

Cheers.

 

[luthj]

The vanagon tends to be near 50/50 weight distribution. With a solid axle up front, and a heavier engine you will probably be 55/45 F/R with passenger/driver and minimal gear. Adding additional weight to the rear in gear/cargo would probably get you back near 50/50.

If you plan on putting significant weight on a rear bumper, or towing, you may consider adding weld in plates to the gaps in the inner rear body wall. I believe the syncro 16 models had plates here to prevent wrinkling of the body skin, especially around the rear seams?

 

[vwhammer]

Front suspension. Having NO brake dive is bad too. Basically you can overload the tire contact patch which can cause brake hop. With bigger tires it isn't too concerning, but I would build in some adjustment on the upper frame side arms to help tune things since you are guessing for these numbers in relation to SPRUNG CoG (the calcs should use the sprung CoG, not total vehicle CoG)

You should also be thinking about overall shock and how much uptravel from ride height you can package. Rough rules. Maintain spring preload at full droop no matter what. Find out how much uptravel you can get from your desired ride height, times that by two basically for overall shock travel. Try and package as much uptravel in from a low stance as you can. This will bring up spring rates and help with body roll a bit. With the van setup, I would be thinking about where to pre-package a front and rear sway bar from the start also.

Cheers.

Oh yeah I totally spaced on my axles not being part of the CoG equation in this instance. Thanks for pointing that out.

For uptravel I am shooting for about 5 inches at ride height and 7 inches of droop for a total of 12 inches.
Unless I really jack this thing up, 5 inches of upward travel is about the max.
I even considered 4 inches up and 8 down just to make sure I had no axle to engine/transmission clearance issues.

The spring preload thing is where I may deviate from your formula.
I assume that if I am crossed up to the point that the spring is unloaded then the opposite spring will be functioning as the fulcrum for the axle.
With this, some of the force being applied to the stuffed tire will be transmitted to the drooping tire to aid in maintaining traction.

I am running an air spring that only has 10 inches of travel but I am shooting for about 12 inches of total travel.
I intend to build a seat for the spring that can drop out for that extra 2 inches of droop that I am after.
It will be a cone shaped apparatus and will be assembled in such a way that the spring will never actually travel completely beyond the cone.
This will insure that it will always go back to its seat as it is compressed.
Overall droop will be limited with straps.

Of course the question arises, will it be worth the extra complexity for 2 more inches of droop, especially since I will have lockers front and rear?
To this I say watch some videos of a Vanagon Syncro with lockers trying to traverse any diagonally uneven terrain.
Its complete lack of wheel travel makes lifting a wheel inevitable and just watching them flop back and forth in this situation is unnerving.
I figure the more time the tires are on the ground the more controlled the transition cycle will be going from stuff to droop.

I am also planning on some fat anti-roll bars with disconnects to keep body roll to a minimum on the streets.
With the tallish nature of this van one would have to be crazy to run with out anti-roll bars.

I even have an electrical engineering friend that I have been talking with about some controls for the airbags to help with stability off road with the anti-roll bars disconnected.

Of course all of this means nothing if i don't get it running and drivable so I guess I better get at it.

 

[Metcalf]

You can do what ya want, but zero preload, or a negative spring rate at max doop, never seems to work out well to me. It might give you a little more sloppy uncontrolled travel, but it will cost you axle control in a lot of other areas. My advice is to keep it simple. Simple Simple.

Air bags are an interesting idea. I have seen a few rigs that work well with them, but I would still limit the overall travel at the bag to keep it alive and have a bit of preload at max shock extension when aired all the way up.

Even if the springs and shocks are mounted completely in the same outboard position, unless they are VERY close to the tire you will always gain a little bit of articulation travel vs vertical travel. It is good to have the shock/spring mounted as close to the tire as practical for a lot of other reasons, but packaging makes it impractical to get them REALLY far outboard.

If the suspension can eat up a 10" travel shock front and rear, you won't be lifting the tires that often. At that point, if you do lift a tire it won't be the end of the world for predictability. In the end, I would recommend quality of travel vs quantity of travel.

 

[vwhammer]

Dang it.
You make too much sense.
I am looking for someone to tell me to run 18 inch travel coil overs and hydraulic steering and that it will work just fine on the street.

I blabbed on from the beginning about using tried and true bits and ideas in the name of durability and reliability but knew I wanted to push the boundaries a little bit. That's what I do.
Otherwise, I would not be building a Vanagon.

Truthfully I came up with the loose spring seat idea (well more like decided to steal the idea) because I wanted to run the air bags but could not find any of suitable quality that were the right diameter and had the travel numbers I was looking for.

I paid a pretty penny to have these bags shipped from Australia because they almost met all of my criteria... Almost.

Since I plan to sleep in this van, the bags will be good for pulling into camp and leveling out the rig at the push of a button or two.
I assumed with the top heavy nature of such a design it would be good to adjust the vehicles attitude on the fly should things go pear shaped.
I also imagined being able to pump the suspension up 3 or 4 inches should I get hung up on something.
Lastly I thought it might be nice to drop the rig down a bit and soften it up for interstate travel.
The bags just made sense to me and still do.

When it is all said and done, more or less, I just want it to work like and last as long as an 80 series land cruiser but with my own little spin on it.

Alas, I do not have then engineers or money that any of the major manufactures have so I kinda just hafta wing it... Sort of.

 

[Metcalf]

I think the bags aren't a bad idea, I just wouldn't make them drop out of the mount or anything fancy.

Dropping them down for the highway might work against you. Less uptravel is never really fun. It will also change your suspension and steering a bit.

I'd decide on a ride height and stick with it 99 percent of the time. You can play with the bags, but you won't want to have to do that all the time.