1991 VW Syncro — Driven in and out of Shop!

I got the day rolling by finishing the engine install. I took extra time sorting the wiring harness routing and also discovered more Syncro-specific changes I needed to make. The airbox mounts to the body and, with the engine sitting lower, the intake boot between the air flow meter and the throttle body needed to be swapped with the one from the donor. Fortunately, it was in good condition. The other item was the oil filler tube. The van has a trap door behind the license plate that gains access to the dipstick, oil filler and coolant overflow bottle. With the engine lower, the 2WD filler tube was too low and the angle was wrong, causing it to foul the heat shield tin. There is also a coolant bleed line that runs the perimeter of the engine compartment and with it mounted to the body, the lower sitting engine, plus the changes in the Syncro’s cooling system meant the original coolant lines were too short. Of course it is special small diameter coolant line that no one has at the local parts stores. I discovered, too, that I had neglected to purchase one of the larger Syncro-specific coolant hoses. There is four and I’d gotten all but one. GoWesty had also sold me the incorrect seal for the front differential input shaft. Fortunately, my lovely assistant was available to drive down to GoWesty and pick up the parts we needed.

Syncro Intake Boot & Idle Stabilizer Line

One of the cool Syncro parts is a little dust separator that lives in-line from the intake snorkel to the airbox. It is a small device with fixed vanes in it that, as the air passes through, must cause a vortex which directs dust into a small bowl that is clipped to the bottom. Neat!

Syncro Dust Separator & New Silicone Boot

The power steering pump was still wired up out of the way from the engine removal, so I decided to remove it and its reservoir and associated hoses/lines to be cleaned/rebuilt. I bought a pump rebuild kit from GoWesty and was really looking forward to getting this thing resealed. It has been leaking for awhile now and everything in the vicinity was messy. I disassembled the pump and reservoir and thoroughly cleaned all the bits and then reassembled it with the new seals. It was a joy to finally have a clean reservoir and pump. I got them installed, filled the reservoir and gave the pump several rotations by hand to, hopefully, prime it. With the engine in the back and the rack in the front there is an awfully long way for the power steering fluid to travel.

Disgusting Power Steering Pump & Reservoir

All the Bits Clean and Ready for Assembly

Around that time my lovely assistant returned with my parts and I got the hoses in and started filling the cooling system. Again, with the engine in the back and the radiator and heater core in the front there is a fair amount of bleeding to do to eliminate all the air in the lines. At this time, I just let it gently fill on its own since I wasn’t ready to start the engine.

I replaced the front differential input shaft seal, installed the drive shaft flange and then the driveshaft itself. I’d bought a new drive shaft to replace the ridiculously badly vibrating one from the donor. I loosely hung the skid rails to get them up off the floor and in preparation for when I would install the rear skid plate.

Skid Rails & New Driveshaft

I moved onto the interior. I hooked up the main and auxiliary batteries and closed up their compartments. I swiveled the seats back around the right way and set about installing the two vacuum switches for the front differential lock and the decoupler. I hadn’t run the vacuum lines into the passenger compartment yet, so I did that and spent time under the van getting them bundled and zip tied safely and neatly out of the way. Once I had the Syncro control panel all hooked up and installed again, I got out my hand vacuum pump and hooked it to the decoupler and locker engage fittings and applied vacuum. I switched on the ignition and verified that the engage lights were lit on the control panel — success! I had upgraded my dash lights with blue LEDs. I had a couple of spares and installed them in the Syncro control panel. The panel has a green tinted plastic image, that illuminates green for each part of the system — front diff lock engaged, decoupler engaged, rear diff lock engaged — and I was pleased to see my blue LEDs were able to still shine blue through the green tint.

Decoupler Engaged

I still needed to make the rear brake lines. I could only source 20″ or 30″ universal lines locally and since I don’t have a quality bubble flare tool (I will definitely be getting one), I had to make do with the 30″ since the 20″ was nearly exactly what I already had. It was very annoying, because the 20″ was just barely too short, which meant the 30″ was ridiculously too long. I had to make sweeping “S” bends to use up all the excessive length. The esses run along the top of the trailing arms, so they are basically protected and out of the way. I will be making proper length lines once I get the correct flare tool. Once the lines were in, I summoned my lovely assistant and she helped me bleed the brakes and clutch.

Crazy S-Bend Brake Line

I’d put off the process of switching the oil filler tubes, so I set about doing so. I drained the engine oil, replaced the filter and removed the 2WD filler tube. Then I went out to the donor and removed the tube from the old engine. I cleaned, disassembled, bead blasted, painted, reassembled and, finally, installed it. I added five fresh quarts of Mobil 1 15/50 and gave everything a double check prior to starting the engine. I got it fired and finished filling the power steering system. I ran the steering wheel through its motion left and right to get the system online and fluid running through it fully. I also continued the process of adding coolant and bleeding the system.

I set the van on the ground and pulled it out of the shop and backed it back in. It was nearing midnight and definitely bed time.

Day Thirteen complete!