Tuesday, December 26, 2006

VW - TULZ Part Eight

TULZ – Part Eight

Getting Your Shift Together

With your tranny at one end of the vehicle and you at the other, selecting a gear can be a bit of a bother. Volkswagen came up with an elegant solution to the problem using only two levers and a torque tube. One of the levers is your gear-shift. The torque tube is the shifter-rod. I'll tell you about the second lever in a minute.

The shifter-rod is a long piece of light-gauge steel tubing that runs from the gear-shift lever to the tranny where it connects via an elastomeric coupling. It is hidden inside the central tunnel in a bug. On the bus it's hidden in that tube just above the heater duct under the cargo bay floor. The cockpit-end of the shifter-rod is fitted with a socket. The gear-shift lever fits into the socket and is indexed by a pin.

The socket is the second lever in the system. It pokes up perpendicular to the line of the shifter-rod. It doesn't poke up very far and most folks overlook the fact it functions as a lever but it is crucial to the system, allowing you to rotate the shifter rod. It is the rotation of the shifter rod that selects the particular gate, 1-2 (no rotation) 3-4 (to the left) or R (to th right). It rotates when you push the gear-shift lever left or right. Once you've selected one of the three gates, to select a particular gear the shifter rod must move forward or aft, again controlled by the gear-shift lever.

As with all levers the secret to success is in the fulcrum; the pivot point. For the gear-shift lever the pivot is a spring-loaded ball & socket arrangement built into the fitting that supports the gear-shift lever. For the shifter-rod, the pivot is a nylon bushing in a bracket concealed inside the central tunnel.

To prevent selecting reverse gear by accident there is a lock-out plate under the fitting supporting the gear-shift lever. A flange on the gear shift lever rides above the lock-out plate for the four forward speeds. To select reverse you select the reverse gate then push DOWN on the gear- shift lever. This defeats the lock-out plate and allows you to input the down & back motion that selects the reverse gear in the tranny. (The motions are REVERSED at the tranny because of the lever arrangement [ie, pushing forward on the gear shift causes the shifter-rod to push backwards, etc.]. You need to keep that in mind when you're checking out a replacement tranny at the junkyard.)

Thanks to just three friction points and a superb balance of lever-arm ratios, Volkswagens are noted for their crisp, precise shifting. It takes only finger pressure to flick from gear to gear, giving the experienced driver a distinct advantage over anyone wrestling their way through the changes on the typical American gearbox. That was then.

Today, the typical Volkswagen's gear shift is about as crisp as mush and finding reverse can become a snipe hunt. There are a number of reasons for this woeful degradation but the most amazing part of the puzzle is that, never having driven a new Volkswagen, a majority of VW owners believe such poor shifting is normal!

Why is the shifting so bad? That's a good question but here's a better one: When was the last time you greased your gear shift? Howzabout the nylon bushing in the tunnel? Whadabout the lock-out plate? (See? Now you know why :-)

Another common maintenance fault is failure to replace the tranny mounts. They're made out of natural rubber that breaks down when it gets greasy and trust me here, yours are greasy. The same problem attacks the shifter-rod coupling.

Up on the other end of the system, it is a LACK of grease that causes the problems. Without periodic lubrication the shifter-rod eventually wears out the nylon grommet and begins rubbing its way through the steel bracket. Once it wears far enough the shifter-rod drops off the end of the gear shift lever and you're stuck, literally, in whatever gear you happen to be in. By the time that occurs both the shifter rod and the bracket will have to be repaired or replaced but in a lot of cases the vehicle ends up in the scrap heap. 'Tranny's locked up,' the guru tells the kiddie. Which isn't incorrect but it's sure as hell inaccurate.

So what's the cure? Easy. You pull the shifter rod and replace the nylon bushing, grease things up, put it back together and promise to keep it greasy thereafter. Of course, if the bracket is worn to an oval, putting in a new grommet won't help very much. In those cases you need to drill out the spot-welds securing the bracket to the tunnel and repair the bracket. Or just cut the top off the tunnel, do the repair and weld it back on as a complete assembly, being careful to NOT install the nylon grommet until all the welding is done. (Nylon melts, right? And gasoline explodes. Your fuel pipe is also inside the tunnel.)

Repairing a worn shifter-rod is a bit more difficult. You can't use a sleeve; it won't fit through the grommet. And it takes a pro to do an inline repair of thin-wall steel tubing. One method is to do the repair with a sleeve then to fabricate a new grommet from a block of Teflon to match the larger diameter of the sleeve. This is a good fix because the Teflon block will last about ten times longer than the nylon bushing. This is a more permanent fix and it's doable but it's a lot of work. The smartest method is to simply pull the gear-shift lever about once a year, clean things up and apply fresh grease. But nobody does that. Too much trouble or something.

Doing the tranny mounts (most folks call them 'engine mounts') is a no-brainer; the instructions are in most of the manuals. And the shifter-rod coupling is mother's milk; you can get at it from under the back seat of a bug. (Ah ha! I'll bet you've been wondering what that inspection plate was for!)

Buses are a little different, easier in some ways, harder in others. The grommet on the shifter-rod can be gotten to from under the vehicle so it's pretty easy to replace. But the shifter-rod is a bear. On the bus, they use a two-piece shifter rod. (Because the gearshift lever is in FRONT of the front axle.) First, you separate the two then you pull the engine, pull the tranny (and the rear axles if it's an early bus) THEN you can remove the shifter-rod, which pulls out to the rear. Inside the tube running under the cargo bay the shifter-rod is supported by two nylon grommet-thingees that clip onto the shifter-rod. They come in two sizes so be sure you get the right ones for your ride. Don't trust the clerks here. A certain after-market retailer kept sending me the wrong size, insisting there was only one type. I finally bought them from somebody else. Here again, you can machine a better, more durable part from a block of Teflon… if you happen to have the Teflon. And an engine lathe… and know how to twirl the knobs.

It goes something like this: You gotta have good tranny mounts because that's what holds the tranny in alignment with the shifter-rod. Soft or rotten tranny mounts, the nose of the tranny kicks up & down, wears the hell outta things and makes it very difficult to select the proper gear. You gotta have a good coupling because once the coupling starts to go you lose radial motion; you can't select the full range of gears. It might work fine in first & second but you can't get it to rotate far enough to pick up third & forth, or over the other way to catch Reverse. You gotta keep the gear shift greasy or you'll wear out the lock-out plate, preventing you from finding the right gear. Like the man said, keep her greasy, she'll go a long time :-).

Big mistake in tranny mounts and couplings is to use those hard urethane jobbies. They were designed to handle the high-g loads imposed on the mounts & couple by off-road racing, where the vehicle catches a lot of air-time. They transmit more of the load – and more of the noise – into the chassis. They have no place on a street machine. (But kewl, right? Peek under there, see those big chunkies of red urethane! Macho, eh?) This'll come as a big surprise to the kiddies but mechanics notice stuff like that. It tells them they can sell the sucker anything at all :-)

Another cruel joke is trying to cure a shifting problem by installing one of those kewl gear shift kits. All they do is alter the lever ratio of the gear shift lever but in doing so they can mask a lot of problems. The wiser course is to return the system to spec and then decide if you really need it. In most cases, you don’t.

If, once the system is returned to spec, you find your life simply isn't complete without a speed shifter, take a look at the one sold by Gene Berg Ent. Like most of Gene's stuff, the shifter is well made and priced accordingly. But at least it works. The typical 'speed shifter' is a lo-buck piece of Taiwanese crap aimed squarely at the kiddie market. Some are difficult to install and tend to come adrift while others don't work as well as the stock system.

Recently I've been seeing an increasing number of VW's with shifter problems. By the time it gets to me it has usually been through the gauntlet of local experts, meaning I see a lot of bailing wire & sheet- metal screw fixes. The coupler is liable to WELDED to either the hockey stick or the shifter rod and finding the remains of a bungee cord or block of wood(!) inside the tunnel no longer comes as a surprise. By the time things have gotten that bad you really don't want to know how much the repair can cost; often times it's more than the vehicle is worth. Unable to shift gears and unable to afford the repairs, the vehicle often ends up on the junk pile to be salvaged for parts. This is really unfortunate since the shifter is a very simple system, easily maintained. Which begs the question: How's yours?

You've gotta be able to stop. You've gotta be able to steer. The engine should start every time, all the time, regardless of season and you have to be able to shift your gears. You need certain lights, a horn and wipers. Those are the minimums. The bitchin' sound system and the three thousand dollar paint job and all the rest of it is just so much junk if you don't have the basics underneath. The record shows most have paid more attention to the junk than the basics.

-Bob Hoover
-30 April 2K

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