Assembling the Stack

After the Hamster Dance to get two lousy dowel pins, I was more than ready to get on with the bolt-up of the adapter plate, flywheel and clutch components as the next step to moving the engine into place before the weather drops to freezing. I don't often get to spend sustained time on this project; I just maunder along, chipping away at it like sculptor chiseling on a monument. There's a lot of mountain left, but there is wisdom in just looking at the piece of stone in front of you and just working that bit, rather than trying to constantly hold every step in your mind while you work: That way lies madness...or failure.

So I happily unpacked the components from Outfront Motorsports / Rocky Mountain Westy and got to it.

First: The addition of those silly dowel pins. They were a pinch fit, so I put them in the freezer overnight, then the next day heated the case bosses with a torch. Then I used a lightweight 6oz tack hammer to tap in the dowel pins. Fortunately, the depth isn't critical when working with the adapter plate. I still did it properly so that both tips were flush when I was finished. No one will ever see it. But I'll know its there, and that it was done right.

Now I was finally set to add all of the goodies in the kit. The first job was to remove the bottom studs that came from the factory. They're being replaced with bolts from the kit because it isn't the engine that bolts to the transmission, it is the adapter plate, which has its own set of properly sized studs relative to the size of a VW 091 transmission.

Not much to get ahold of to remove the old studs. Thankfully, they didn't protest when being removed.

With the old out, I rehung the adapter plate on the dowel pins, which blessedly fit perfectly. 

I added the bolts to secure the adapter to the engine, and then added the studs for the transmission side. Threads for each were liberally juiced up with red loctite, a thread sealer that cures in the absence of oxygen, meaning when you juice up the threads, the adhesive cures from the inside (no air) to outside. The red color coded loctite is industrial strength: If I want those bolts or studs back out, I'm going to need to heat the adhesive around the metal to 560°F before it will let go. So better do it right the first time.

Now that I had the adapter mounted permanently, it was time to add the flywheel.

The flywheel slid over the crankshaft hub. The perimeter bolts were turned into place by a few threads just to keep track of them. The same for the three small roll-pins that act as dowel pins for aligning the clutch plate: If they won't be in the way, put fasteners in early so that you don't lose track of them. At this point the flywheel is just set in place, not secured.

Starting to look snazzy! Note that the types of steel that the flywheel is made up are different: the teeth around the edge that the starter engages are specially hardened to take the punishment of being bashed into by the starter gear before it gives the flywheel a twist. The weight of the flywheel also smooths out acceleration and deceleration: Too heavy and you spend a lot of power getting it turning, too light, and every microscopic variance at the throttle is immediately translated to the transmission. 

That's fine for a race car, but for a road vehicle, especially a heavy one like the VW Bus, you want the moderating effect of a fairly heavy flywheel.

Now we permanently mount to flywheel to crankshaft. Here's where we break out the monster tools:

Eight bolts gooey with loctite were added and torqued down to 55 foot-pounds each. 

 In the foreground is my Christmas present from a few years ago: a beautiful Brownline Digital Torque wrench with a 2 foot long body and a thick handle so you can really lean on it without worrying that something will break. Despite being built like a tank, it is probably one of the most precision tools that I own.

I don't just magically 'know' what torque is correct: each of the bolts that has been added in the build up of the stack has come with values from the vendor for what torque they should be set to. This is not something you want to guess at. So you tell the wrench what the value should be, then start pulling on the wrench until it chimes. Ta-da. You're exactly on the mark.

With the flywheel in place, it was time to add the clutch disc, one half of the friction portion of the clutch that does most of the wearing when shifting and then add the clutch pressure plate, the other half that the disc rubs up against when engaging and disengaging. The trick is that the disc has to be centered in the middle of the flywheel, but you can't get to it because its covered by the clutch cover. To the rescue: A clutch alignment tool: A plastic shaft with flutes on it to mimic the transmission input shaft that the clutch disc mounts on as it is alternately clamped between the pressure plate  and flywheel (power engaged) or released by the pressure plate (power disengaged, like when you're changing gears.) 

The grotty looking clutch pressure plate being slowly bolted down in a criss-cross pattern of the six bolts that hold it on. The clutch disc is hidden under the cover, but you can see the input shaft alignment tool in the middle that holds the disc centered perfectly as the pressure plate descends over it, eventually holding it in place.

The 'fingers' in the middle of the pressure plate are actually springs that you are pushing against when you put your foot down on the clutch pedal. When you overcome their initial resistance, they flower out and cause the pressure plate surface that had been clamping the disc to retract and take pressure off the disc, causing the turning power of the pressure plate to be disengaged from the clutch disc which is attached to the transmission by the input shaft that our alignment tool is mimicking for now.

So why did I re-use the clutch disc and cover plate from the Bus? 1) Because there's nothing wrong with them. Treated well, a clutch will last 100,000 miles or more, and this clutch had less than 5k miles on it when the vehicle was put into storage 14 years ago. 2) A new disc and cover plate is about $160. Why would I spend that just to have something new and pretty that is a 'wear component,' that is, it is designed to be used up during its lifespan? A tire is a wear component, replaced every 40k miles or so. The wheel that the tire is wrapped around is not a wear component: unless damaged, it does not need to be replaced. I'll be back in to replace this clutch pressure plate and disc eventually...in about 20 years if everything goes right.

The final reveal: adapter plate to engine (3 bolts), flywheel to crankshaft (8 bolts), clutch disc added and held aligned to the center of flywheel by the alignment tool, shown withdrawn. The smooth tip of the tool goes all the way into a recess in the center axis of the crankshaft (which you can see all the way down at the middle of the picture.) The fluted neck of the tool holds the clutch disc perfectly centered. Finally the pressure plate (6 bolts and aligned by 3 pins) is bolted down to the flywheel. The stack is now complete, and ready to be mated to the transmission.

This was a good afternoon to go slowly and document as I went. With the engine side essentially finished, the next step is to maneuver the engine into the compartment and with it oriented correctly in 3 degrees of rotation (roll, pitch & yaw) slide the input shaft from the transmission down into that cavity without kinking anything. For that part, I'm going to need help, because I can't single-handedly keep 250 pounds of engine supported and oriented all while its being mated together. That's when it will be time for 'a little help from my friends.'