Wheel Studs

Last weekend brought the final track event for NCC BMW CCA this  year at Summit Point.  Although I had a great time as usual, the weekend wasn’t completely worry free.  If  you run wheel studs instead of bolts, you may not be aware that you need to replace them every couple of years.  I know this, but I tried to delay for the winter, but the gods of oxidation thought otherwise, teaching me a few important lessons.

Lesson 1: Don’t cheat time. If you know a part should be replaced based on time and not wear, don’t push your luck.

Lesson 2: Just because something tightens to torque, doesn’t mean it isn’t about to snap.  I broke two bolts.  Both tightened to torque when cold, even though both had already rotted half-way through.

Lesson 3: Buy a bolt extractor before you need one.

Lesson 4: Assenmacher makes a really cool stud removal tool which will make your life so much easier.  (Assenmacher, that’s funny…)

Here’s a lap when everything went right.

MINI R53 Manual Transmission and Differential Fluid Change

The oil MINI uses in the Getrag 6 speed manual transmission is supposed to be a lifetime fill. I’m not sure what that’s supposed to mean: If you kill the transmission because of bad fluid, that’s the end of its lifetime.  A safer bet is to change it yourself every 30-50,000 miles. It’s cheap and easy insurance, and will probably give you smoother shifting as well. The fluid you want to use is Manual Transmission Fluid with the GL-4 specification such as Redline 75W/80W MTF.  You’ll need 1.5 quarts for the R53.

Safely place your car on jack-stands with the car level, and make sure you get it high enough to get your bottle of new fluid with pump attached underneath it with enough room to actually pump the fluid. On the R53, the there are two 8mm hex plugs on the side of the transmission across from the PS fan. The lower plus is the drain and the top one is the fill.

If you just want to check the fill, work with the transmission cold and remove just the top plug.  You should be able to stick the tip of your little finger into the hole and just touch the fluid. If a little fluid drains out, that’s OK, you either don’t have it quite level or when it was filled it wasn’t level.

If you’re going to change the fluid, it’s a little quicker if the transmission is warm. Make sure you have an oil pan that’s big enough for at least two quarts of fluid. Remove the top plug and then remove the bottom plug. I drained it through cheese cloth and over a magnet to see if any metal shavings came out. I drove the car home from Summit Point in a driving rain storm with no clutch — I fully expected to see bits of my second gear synchro in the drain pan, but was happy to see it was relatively clear and metal shaving free.

Once all of the old fluid has drained, clean the plugs and the threads on the transmission housing.  Use a Q-tip or rolled paper towel to get anything that may be left behind.  Replace the bottom plug and torque to 32 ft-lbs of torque. Use your fluid oil pump to pump oil into the upper plug opening until it starts to come back out. Clean the threads, install the plug, and torque to 32 ft-lbs of torque.

Go for a test drive and enjoy the silky shifting smoothness you had forgotten about.

MINI Brake Ducts, Part Tres

Getting the brake ducts right on the MINI is slowly becoming my white whale project (call me Ishmael). In Part Deux of this adventure, we found a good cooling solution using brackets from Chris Sneed,  but the location on the passenger side ducting was less than ideal.  First we got the hose caught in the crank pulley (which was fixed by use of a sleeve before any real damage was done), but most recently, the hose got pinched under suspension compression and the wire from the hose shredded the (brand new) CV boot forcing yet another axle repair and massive grease clean-up.

This time we’re trying a smaller diameter hose — 2.5 inches vs 3.0 previously. The brackets at the wheel carriers were modified for a smaller diameter fitting, which we’ll weld over the winter break if this works out.

We got a Mishimoto reducer to fit the 3 inch brackets in the bumper and some aluminum tubing to form connectors and to protect the crank pulley.

The eventual solution turned out pretty well. Since the hose still matches the opening in the bumper there shouldn’t be any loss in cooling, and now with the reducer in place, it will be easier to remove the front bumper cover. There doesn’t appear to be any binding at steering lock. And when we jacked up the hub, there doesn’t appear to be any binding at full suspension compression either.  We’re running at Summit Point in a couple of weeks so we’ll know more after that event.

Leave a comment if you have a better way to route the hose on the passenger side.


Porsche 996 Carpet Replacement

Keeping mind my past experience with a carpet swap in a BMW E30 some years ago, I finally found a good replacement for the carpet in the 996 and, uttering those infamous words “how hard could it be”, set off to do the carpet swap last weekend.  If you’re curious how much of your interior you have to remove to do this swap, here’s your answer: almost all of it.

Pelican parts has an excellent DIY write-up which I won’t duplicate here, but do have a couple of helpful pointers for those who endeavor to follow.  Here are the key lessons learned from my experience:

  1. Just cut. Follow the Pelican Parts top tip and just cut the new one in half down the middle (under the center console.) I didn’t do that, and it would have made it a whole lot easier to maneuver into position in the passenger footwell.  You might have to use some extra contact cement along the center tunnel since the two halves aren’t held together any more, but it is totally worth it in reduced aggravation. And you won’t have to remove the shifter cables from the shifter or the e-brake handle mechanism from the tunnel.
  2. Give yourself the weekend. The two hour estimate is off by a factor of 5 (maybe 10.) It took me 2 hours just to remove the accelerator pedal (and I’ve done that before.)
  3. Bend don’t remove side panels. To release the rear corner of the carpet on each side, you have to remove the rear-seat side panels from their lower catches.  You don’t need to remove the entire panel, just carefully bend the panel as you pull up and you can free it from the slots in the carpet and have enough room to maneuver the new one into place when the time comes.
  4. Frustration ahead.  The accelerator pedal can be a bear to remove and reinstall. To remove, take out the set screw, pull forward by the top (what looks like an old cell phone antenna housing) to release the top catch, then slide up to release the cleat. Expect buckets of frustration when you try to put it back.  It’s easier to do if you do put it back before you reinstall the seats.
  5. Don’t turn the key. Once you disconnect the electrical connections to the seats, you will get an airbag light if you turn the key to the on position (to roll down a window, for example). If you have a reset tool like the Schwaben Professional Scanner (with the right Porsche software module from Foxwell) you can reset it yourself. Otherwise you’re heading to the Dealer and pleading for them not to charge you for the reset.

The photo above will help you visualize what’s going on with the accelerator pedal module. When you remove it, you pull out to release the round peg, then pull up to release the square-ish cleat. To install, slide the cleat in first, then push down and forward to lock the peg. Secure with the screw. Or better yet, upgrade the whole thing to a fully adjustable throttle assembly (though that probably means cutting your new carpet….)

You also learn interesting things by tearing apart your interior, like how unnecessarily complex the center console design really is or that there is in fact a coin tray in the console box (which you have to remove by carefully prying the top to get to one of the screws).


On top of old Smokey

It’s the scene every 996 owner fears most.  You start the car, there’s a puff of smoke followed by the death rattle and it’s game over.  Time for a new engine.   (Or more likely, a new car as engine and car are about the same price these days.)

The interesting thing here was that there was no rattle, just smoke.  I had been at Summit Point the previous day and had a huge smoke cloud come out after turn 10.  Coolant was a bit low which was worrying, but the smoke was just there at startup which usually indicates a bad Air Oil Separator (AOS), which is a common failure on these cars.

We sent an oil sample off to the lab just to be safe and had the car towed to TPCRacing in Jessup. They did a great job sorting it out and getting me back on the road again.  It turns out I had two unrelated problems: leaking water pump and bad AOS.  I had planned to have the AOS changed whenever the next time I got a new clutch and I suspected it was about time for the water pump, but probably should have had it done already.  So I dodged a bullet.

The water pump (996-106-011-57-M100) was leaking at the housing and through the pulley seal. You can see from the photo below that the play in the bearing had allowed the blades to touch and score the block just a bit.

Many people make the mistake of using a pump with metal blades thinking it would be an upgrade. The problem is that when they contact the block, the debris can be catastrophic. The plastic impeller fails more gracefully.

Early expansion tanks have a tendency to fail on track cars, so we got the updated tank while everything was apart (996-106-147-56-OEM). Shop around.  Genuine Porsche tanks can run as much as $600, but you should be able to find them for around half of that (which is still nuts…) if you shop around a bit.  In this case, the hoses were also brittle and failing (996-106-850-05-M100).

The Air Oil Separator is supposed to separate oil vapor from the crank case and return it to the intake path. This appears to be an original item. They have gone through a couple of revisions since (996-107-023-55-M100). When they start to fail, you get about a tablespoon of oil that pools in your cylinders causing smoke at start up (see video.) When the fail completely, you can hydrolock the engine. Given where it sits on the engine, it’s impossible to inspect visually.  You should think of it as a wear item and replace it whenever you get a clutch (like the IMS bearing.)

We rounded out the repairs with a new idler pulley and belt.  The idler pulley felt OK when it was on the car, but fell to pieces when we took it off.