The Quattro Syncro Project

August 29, 2013

I have had a Syncro van sitting in my lot for many years, parked because of a broken transmission like many others out there waiting for the day the affordable syncro trans will come along.

I’m hoping to make it happen by attempting to use the very affordable, available, and reliable 01A transmission and front diff used in the Audi and B5 4motion Passat.

The engine I’ll be using is the AEB 1.8t used in the Audi A4 and B5 Passats.

The wheel base of the Vanagon is 96.7″, the Audi A4 is 103.0″. The A4’s with Tiptronic transmission had a driveshaft that was four inches shorter because the manual trans was shorter. If I use the shorter driveshaft, that will bring my front CV to rear CV length down to 99″ or just 2.3″ of the Vanagon length. I believe the CV’s will allow for that difference.

I’ll first focus on making it drivable, then look into adding the ABS brake system from the Audi as well. The reason I want the brake system is more for the traction control than the anti-lock breaking. With this Quattro system, the brakes can grab a wheel that has lost traction so the wheel opposite it can drive or as Audi puts it, EDL (electronic diff lock).

August 30, 2013

I was able to spend a few hours today on my syncro.

I actually have very little syncro experience, almost all the vans that come here are 2wd.

I had never dropped the front sub-frame from one before. It is really neat that in just a few hours even with very rusty hardware you can drop this down like this.

Sept 3, 2013


This is the donor car above.

I’ve got the front diff, drive shaft and trans in rough mock up position. It is looking good.

The four CVs all just bolt on with what looks like plenty of axle movement.

The length of the drive shaft seems perfect, it positions the trans almost exactly where my 2wd Audi/Passat transmission is located.

One major benefit is the starter will be easily accessible being that it is on the engine side of the bell housing.


Sept 4, 2013

A comparison of the two transmissions.

Sept 9, 2013

I got a lot of the electrical work prepared for going into my Syncro. This is not an uncommon look for my kitchen counter.

I can change the odometer to match what is on my van.

Here is the ABS/traction control controller and a prototype speed sensor ring/CV boot, I’ll need 4 of these, one for each inner.

Nov 7, 2013


Tank is out, cleaned, and wrapped with new insulation.

Nov 27, 2013

Ok, finally get to work on this again. 

I got the replacement roll-over valve for the tank and then promptly broke the other. The second one I got right from a Jeep dealer, only $23.

The tank is now back up in place after I cleaned and drenched the area surrounding it with SEM Rust Preventer (a black wax based coating I have using for a while and am very happy with). I also replaced the fuel sending unit with a new one.

Right now all 10 CVs are bolted up and things are looking good. The fuel tank follows the contour of the transmission like it was made for it. The starter being mounted on the engine side of the bell-housing will be a treat. The slave cylinder also will be an easy job to get to. The front diff (Audi rear diff) is mounted up in place, the drive-shaft is bolted up front and rear with just a jack stand under the center bearing to hold it in place, the engine/transmission assembly is just roughly in place sitting on three jack stands. The engine will now need to be adjusted into position, it should be able to be raised up about 1 1/2 to 2″ from where it is in the pictures.
It will probably take me about two hours of using tape measures, levels, protractors, and strings to shim up the engine/transmission and tap it side to side and front to back until I am satisfied with its position before I can make an engine mount for it. Just looking at it, it looks like the engine mount I make for 2wd Reversed 1.8t engine/trans will be a very close fit.

Dec 4, 2013



The engine and transmission are bolted up in position. The mounts are made, still raw in case any modifications are needed.

Dec 6, 2012


Here is the sloppiest video you will see today of a Syncro running with an Audi Quattro trans and diff.

So I got the engine wired up, ran the fuel lines, relocated the fuel filter, put a battery in it and primed the pump. This engine cranked for about two she ends and then started right up, it’s always nice when that happens on an engine you have spent a lot of time on.

The rear brakes are done and all the mounts for the driveshaft and front diff are mocked up and in place. It is amazing how well all these parts are fitting under the Syncro, this is all used parts right off the Audi A4 with no modifications except to make the engine turn counter clockwise, stock Syncro axles just bolt right on, driveshaft is perfect length.

Dec 10, 2013


I found a better way to make a tone ring for the ABS wheel speed sensors. I drilled a hole every 10*.


I have a 2000 Passat in the shop that I was able to test it on. I plugged it into the left front wheel plug and scanned the ABS controller, no fault codes. Spinning it by hand shows the wheel speed.

Dec 15, 2013


I had a change of plans with the instrument cluster. I had planned to use an Audi A4 cluster but went with one from a 2001-2005 Passat instead. Because I no longer have the syncro front diff, I lost the speedometer cable drive so I need some kind of an electronic one. I also need it for ABS controller communication.

I cut a piece of plexiglass to fit inside the vanagon housing, put it in the housing, stood it up face down an heated it in an oven to about 170°. This made the plexiglass soften an match the contour of the housing.

I then masked off the inside of the plexi to the same shape as the Passat cluster and painted the sides of the clear lens black on the inside so there is no painted edge on the outside.

I also set the mileage of the new cluster to match the original.

June 11, 2014

Syncro Vanagon history has been made!

Quattrosyncro was able to drive it self out of the garage and move around in the driveway under its own power. No strange noises, no binding of axles, no grinding, it actually felt pretty good.

Still a long way to go to make it road ready. there is no coolant in it, no headlights, grills, seats, wipers, etc. etc. etc.

And it looks like hell.


June 13, 2014


Another test run.

Keep in mind that the EDL (traction control) is not yet working, that ABS pump would have grabbed on to the tire that spun and let the others push. I am amazed that the traction is as good as it is like this. The hill is much steeper than it looks and it is wet from raining all day also I only have street tires on it.

June 16, 2014


I have put about 200 miles on Quattrosyncro and all I can say is it is simply amazing to drive. The gearing is perfect! The drive is so smoothe, not a bit of the typical syncro vibration! It feels like the A4, just good smooth power. No clunking when accelerating or deceleration, no binding in parking lots, no constant fear in mind of the syncro trans going bad. I have shown you a glimpse of what it can do offroading and that will only improve once I have the ABS/EDL working.

I am still amazed at how well all the Audi parts fit in- stock vanagon axles, stock Audi driveshaft, stock Audi or passat 5 speed transmission that can be replaced for $350, a cool turbo engine that can deliver 200hp with only a ECM tune. All of these parts are easily available in salvage yards or Craig’s list/eBay etc.

This could be the future for the Syncro Vanagon, there is no other way to update the complete drive-train at this point.

June 30, 2014

I put on a pair of Gabriel 49215 Hijackers Air Shocks in the rear, 60psi brought the back end up level with the front. The ride is still very nice.


Oct 11, 2014



3k mile update. The Quattro van is awesome. No problems at all with any of the mechanical parts. Still running, driving, shifting, sounding great.

Today it drove us to Das Laufwerk VW show and octoberfest at Hunter mountain NY.






The winch is used for other vehicles and my car trailer, I just welded a 2″ receiver to the body and notched the front bumper to go around it. Probably not something a lot of people would want to do if they have a really nice Syncro. I plan on making a 2″ receiver bumper for the rear as well so it can be put back there when needed. I like that the winch is portable because it is never left out in the weather. Also the receivers can be used for other things like a motorcycle carrier.

Jan 3, 2015

5000 mile update-

Not one bit of vibration, grinding, or anything else indicating that it was a bad idea to run this entire drivetrain in the opposite direction it was intended for.

This has been by far my favorite vanagon. It performs great both on and offroad. Nice to cruise 65+ mph under 3k. I’ve got a chipped ECM bringing my hp to about 200hp. I have gotten in the 20s for MPG on the roads, obviously going off-road brings it down a lot.
The only real issue I’ve had was a burned clutch, which was my own fault. Were I to build another one, I’d do it exactly the same.

June 21, 2015


The first drive with this project was to the Litchfield CT VW show. This weekend we made the same trip. This year, half way down it started pouring rain. We continued on and the rain lightened up enough to enjoy a nice evening of hanging out with the VW guys. It started pouring rain again in the middle of the night and into the morning canceling the show.

I put just under 9000 miles on this van in the past year with just a few very minor repairs or upgrades needed. The entire drive train is holding up very well. Not one bit of a complaint from the engine, transmission, driveshaft, front diff.

Sept 24, 2015


10k miles and all is still working just fine. I’ve tested it from -20F to over 100F temps, driven it in sand, mud, salt, slush, dirt, and pavement. The Audi A4 Quattro engine/transmission/driveshaft/rear diff seem to be very happy running counter clockwise.

Back in April 2013, I said this:  “My goal is to run the engine backward using a B5 Passat 5speed transmission in a Vanagon. If this proves to be possible, maybe the A4/Passat Quattro/4motion transmission could be used in my Syncro? ”

Then in August 2013, I said this: “I have had a Syncro van sitting in my lot for many years, parked because of a broken transmission like many others out there waiting for the day the affordable syncro trans will come along. I’m hoping to make it happen by attempting to use the very affordable, available, and reliable 01A transmission and front diff used in the Audi and B5 4motion Passat.”

I’m now claiming victory! There is an affordable transmission that can be used in our Syncro vans.