Writing a monthly tech article can, as you might imagine, be quite a challenge. The articles must be technically interesting enough to hold your attention, without making you go, “I don’t get it. What is unobtainium?” They also must be of interest to you, the readers. So what I try to do is listen to people at club events and on the various on-line forums. This gives me plenty of subject matter, with topics both short and long. Some topics are so extensive that they must be drawn out into two or three parts. This month we have the exact opposite, very short technical notes that would not justify an article on their own. I hope you enjoy these shorter tech notes, and for those of you with a short attention span, these are especially for you!
1- Wheel Mounting Pilot
Over the past few years, I have noticed a greater number of people changing their wheels at driving events. Some have mastered the task, while others seem to be struggling. The greatest problem I have seen is with 914-4’s, 924’s, 996’s and Boxsters.
The reason for this problem is that all these cars have wheel bolts instead of wheel studs. With wheel studs, you just slide the wheel up there; grab a lug nut and start threading it on. If you have forgotten the wrench, it’s not a problem; the wheel is not going to go anywhere. With a wheel bolt set-up you have to hold the wheel up to the hub in the correct position, (two hands) then start the top wheel bolt (third hand?), then start the others (fourth hand?) and now go and get the wrench. This would be easy for superhero octopus-man, but I haven’t seen him at the track lately. Adding in that the lug wrench will always be just inches out of your reach, and you have one frustrating situation.
The solution to this problem can be found in the factory tool kit of Boxster (986) and 996 cars. It’s an aluminum wheel pilot shaft, which will hold the wheel for you (saving the need for another set of hands). There are a few problems with this tool however.
• It is aluminum with a very short thread, and can break off in the hub if the user gets a little over exuberant.
• There is only one in the tool kit (while many newer cars have up to 4 wheels).
• 914’s and 924’s don’t have them at all.
Here is the simple solution. Go to your local nut and bolt distributer and ask them to sell you four bolts. They should to be 14mm X 120mm X 1.5 mm pitch. When you get home, take the bolts and cut the heads off. Then take a grinder and/or file to the end and bevel it smooth. This will help the wheel to slide on easier. You should not have to spend more than $5 for all four bolts.
See figure #1 for the factory version (top) and locally made version (bottom)
The next time you are ready to remove your wheels you will be all set.
• Remove the wheel bolt nearest the 12 o’clock position.
• Install the wheel pilot where the first bolt was removed.
• Remove the remaining wheel bolts.
• Slide off the old wheel.
(See figure #2 – wheel pilot in 12 o’clock position)
The real treat is wheel installation, as it involves no more than sliding the wheel on the pilot and tightening it down. This is also a great addition to the concours junkie’s tool kit, as it makes wheel removal for cleaning a snap.
2- Early 911 gas pedal replacement
Whenever someone looks at a car to judge its mileage, they usually check the driver’s seat for wear. The only other item that sees as much wear as the seat is probably the gas pedal. As time marches on, the gas pedal will start to break down where it’s hinged to the floor. The problem with this is that it will bend over as you mash the pedal down. This will result in one of two things happening, depending on weather it takes a bend to the left or right. You will either get less than full throttle actuation, or you will bend the linkage at the pedal assembly and get permanent full throttle actuation. One results in very little driving excitement while the other results in excessive driving excitement.
Neither is a recommended driving condition, so let’s see about fixing the situation.
The solution seems simple, replace the pedal with a new part and continue safe, moderate, driving excitement.
1- Disconnect the top of the pedal from the throttle linkage by simply pulling back.
• The bottom of pedal is mounted to the floor with two 6mm bolts. These bolts have been there since the beginning of time, and may need a soak with some kind of rust penetrant to get them to come out. If they do not come out easily, wait and soak them some more. You do not want to break these bolts! After they have loosened up, remove them and throw them away. Old rusty bolts that almost break coming out, usually always break going back in.
• Install the new pedal with new mounting hardware that has been coated with some anti-seize compound.
• Pedal option A or B
4a- Replace the pedal with the correct original part. This is an original rubber coated metal pedal with no integrated pedal stop. The part number for this pedal is 901.423.010.00 with a cost of $72.21. Yes that is correct, seems a little pricey for a flat hinged pedal, doesn’t it? (For the more frugal Porsche owners out there, like myself, see option 4b.)
4b- Replace the pedal with a later model gas pedal from a ‘90-‘94 911. They are made of 100% plastic and have an integrated stop built into the top of the pedal. The part number for this pedal is 964.423.111.00 and it will set you back a much more reasonable $8.91. This is one of those Porsche part secrets that just doesn’t make sense. But I have learned not to question the ones where I can get an 88% discount!
(See figure #3 to compare early and late pedal options)
(Early style pedal) (Late style pedal)
• After the bottom of the pedal is installed using the new 6mm bolts, you will have to re-connect the top of the pedal. To do this, hold the throttle linkage with a pair of pliers and press it and the pedal together. You will hear a loud snap as they become completely seated.
• You will have to remove the stock screw in pedal stop from the floor board, or cut the integrated stop off the back of the pedal so the two pieces don’t interfere.
The late model gas pedal “upgrade” works for all 911’s up to ’77 as well as all 914’s.
3-Shift coupler overhaul
As old cars get older and things start to deteriorate, you will find the shift coupler to be a weak point. The jointed shift couplers at the front of 911 transmissions are made up of five separate pieces. There is a steel shaft, an aluminum housing, a pivoting pin and 2 plastic bushings.
(See figure #4)
(Exploded view of shift coupler)
Over the years, Porsche has used several different types of shift couplers. They all provide the same function, varying only slightly in design, but widely in price. They run between $85 to as much as $390, if you happen to have a 924 with a
Type-016Y transaxle.
Fortunately, all of these pieces have one thing in common. The failing piece will most likely be the plastic bushings. While it’s true that each of these parts do have very slight differences in the plastic bushing material, but they can all be repaired with the same bushing kit. The magic kits are manufactured by Daystar products, but can be easily ordered from Performance Products under the Weltmiester name.
The beauty of this repair is that all these cars can use the same kit, which costs less than the sales tax on the 924 piece. This kit (Performance Products part #901747) will run you about $20 plus shipping and handling.
Repair is as follows:
• Remove the coupler from the car.
• Hold the shaft end of the coupler in the jaws of a vise.
• Using a hammer and punch, drive the pivot pin out of the assembly.
• Separate all of the pieces and clean the old bushings from the assembly.
• Press in the new bushings to the aluminum housing.
• Apply small amount of grease, assemble the unit, and drive pivot pin back into position.
• Re-install coupler and make final shift linkage adjustments.
There are few things better than a new, tight feeling shift linkage, and none cost less than twenty bucks.
Good Luck
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