Double Clutch: the second time around

It’s fixed--the truck, in any case. Just for kicks I’ll chronicle some of the more exciting moments (sarcasm)! My buddy came over and kept me company for a while. He also found my camera. The tool pictured here was the end result of a three-hour struggle with a single mounting bolt located at the very top of the bell housing. Can anybody say "monkey boy?"

So the problem turned out to be nothing more than a worn clutch. The last one only lasted some 30k miles for some weird reason. Why? I have a theory which I explain at the end of this post*. Don’t know how a clutch works? Here’s a great link.

Everything came out:

The transmission. The sucker weighs about 100 lbs. It’s not too bad coming out. The transmission has to be slid away from the engine about 4-5 inches parallel to the crankshaft before it can be lowered down. Unfortunately the foot well sits right behind the bell housing (the flared portion of the transmission that mounts to the back of the engine) preventing the transmission from moving more than a couple inches back. No problem; I just lifted the front end of the engine with a jack. With the engine titled the transmission can be pulled away from the engine at a slightly downward angle (from horizontal) allowing it to clear the foot well. The hard part was getting it back in. You have to lift the sucker and “jiggle” it in order to get the transmission input shaft to go into the corresponding hole in the crankshaft. You’ve got to do this without cocking the transmission at all or else the shaft binds in the hole and you ain’t going nowhere! Good thing I’ve been going to the gym!

The clutch cover and pressure plate. This is really a three piece assembly that also includes the diaphragm spring, but it comes out as a single piece. Pictured here is the old one. The rivets that hold the clutch material had just barely begun to rub against the pressure plate so there were no grooves worn into the friction surface.




This is the new pressure plate. What a beautifully freshly-ground surface!







Next came the old clutch. How do I know it’s worn out? Enough of the friction material has worn away that the rivets have begun to rub against the mating pressure plate. You can see this as shiny spots on the rivet heads here. Also, some of the radial grooves on the friction material are no longer visible because they’ve been worn away. A particularly alarming thing I noted was that the clutch wore out more quickly near the hub than at the outer edge.


Contrast the new clutch. The radial grooves are perfect.








Finally, the old flywheel came out. The rivets on the side of the clutch that abut the flywheel had not begun to rub on the flywheel yet. No grooves were evident, though the surface was a little bit wavy. This looks like ripples in the shiny surface in the picture. The new one looks the same, but with a perfectly uniform, fresh ground surface.



* Ok, so here’s my theory of why the first clutch gave up the ghost so quickly. In a nutshell, I didn’t resurface the flywheel when I installed it. Anyone who does their own brakes knows that rotors have to be turned and resurfaced when the pads have become so worn that their metal backings gouge the rotor surface. Now, my friend (another mechanical engineer) and I or of the opinion that there’s not really any need to turn the rotors unless they’re really gouged because the new pads will eventually wear in and conform to the rotor surfaces. This is true, but the price is faster wear of the brake pads because, before the pads conform, they touch the rotor only along the high spots. To get the same stopping power from this reduced contact area the pads need to apply more pressure. More pressure means the pad material wears away faster, at least until they conform to the rotor surface. Since brake pads are pretty thick and the unevenness in the rotor surface is usually pretty small, the faster wear during break-in doesn’t matter too much.

Not so for the clutch. The clutch is super-thin; only about .040” on each side! So, even slight surface imperfections on either the pressure plate or the flywheel are likely to eat up a significant portion of the clutch before it wears in and conforms to those imperfections. This time, I installed a new flywheel with a perfectly flat friction surface. Ditto for the pressure plate.

RETURNED TO SENDER

(What good would it have done for those lines to have been delivered? Maybe USPS got it right. Just a little more for the shoebox.)

____________________________________________________


In other news, to the left is pictured my truck's transmission. I yanked it today and it's sitting on my garage floor. The clutch was slipping a little though I just changed it about a year and a half ago. Here's the rub: the new release bearing that came with the clutch kit I installed was noticeably narrower (shorter in the axial direction) that the original one. I wonder if this is causing the problem. The clutch is hydraulically acutated, though, so it's self adjusting. This means that even if the fork that pushes out the release bearing to disengage the clutch is offset a bit as a result of the narrower bearing, the clutch should still function appropriately since the slave cylinder should take up the slack and still move the fork with the same length of stroke as usual. In other words, the slave cyliner still should move the fork the same amount, though the starting point may have moved a little due to the narrower bearing. Anyway, this is a problem for tomorrow.

Right Number

I took a little break from writing, but I just had a dream that was too good to keep to myself. Here goes:

I’m playing hooky from class, sitting on the couch at a friend’s house laughing it up. I get a call on my cell phone. I hear in a meek voice, “Hi.” Ok. “Hi, who’s this,” I respond. The voice won’t tell me his name. Ok, what’s with this Bozo? The voice tells me, “This sounds like [my name],” Adopting my official and distant tone, I confirm, “Yes, this is he,” careful to get my grammar correct. “To whom am I speaking?” No answer, just a sigh. “Can I help you? What can I help you with?” An even deeper silence. I shoot a questioning look at my friend sitting on the couch in front of me. He shrugs as if to say I should hang up. I almost do, but the way he sighed…. I get the distinct feeling this is someone who’s distraught and a thought occurs to me: this may be someone I just recently met, say through church, who’s calling me in a time of crisis. I get the sick thought this person may be on the verge of killing himself or something! “Are you all right?” A melancholy sigh. Damn, my suspicions are confirmed. My friend thinks he’s funny so he suggests I tell the caller to meet us for lunch at 1pm along with Susie, John, Bob and the rest of the gang—made-up people. I do, however, suggest to the voice that he meet me for lunch at 12pm. And then I immediately regret it. After all, I have no idea what kind of mess I’m inviting into my life. I don’t know where this person is calling from; they could be nowhere near campus. What makes me think he might be near me or that he’ll be able to come meet me? Was that the right thing to do for a man in crisis? Maybe I should go to him, like now?

Well, I may as well try to find out who this person is. “Do I know you from church maybe? I feel terrible that I don’t recognize your voice.” I mentally go through as many of the new people I’ve met at church recently as I can remember. I just can’t place the voice; I don’t know if I’ve ever heard it before. He responds, “My voice? Oh, no one pays much attention to me anyway. I guess you wouldn’t recognize it.” I try a different tactic. “So where are you at?” “I’m at Chris’s.” Ok, that might be useful. “Chris…Chris…do I know Chris?” Again, no direct answer, just, “I tried to fax you three times!” He says this last with a plaintive hurt and a quaver in his voice. I’m feeling terrible all the while. This guy is obviously in pain. I wish I could help him somehow…

* * *

And then I wake up. I think about the dream a little bit and within 30 seconds I realize who just called me and that it was He who wanted to help me, if only I would read the Word on the fax He sent me. I prayed and then wrote this so that I wouldn’t forget.

Burger Fervor

This is me staring at my boots. I love those boots. I have about three pair and I love each of them. These in particular have been with me through my mountain-man day trips into the local national forest, they've trudged through knee-deep Boston snow, and they've kept me steady on my feet as I shoot the heck out a harmless piece of paper (rifle case in the background). As I'm sitting there taking a picture of my feet I'm thinking, "Hmmm...a burger from Pete's would be great about now!"


So I make my way over to Mr. Pete's Patio, the best burger joint in Southern California. Other folks make good burgers, but they're not true burger joints as I see it. Here I'm sitting in my car taking this picture as I decide whether I want extra onions on my burger.






The smells of charbroiled meat and deep fried zucchini and mushrooms are wafting out the window. With my other hand I'm reaching into the glove compartment to see if I still have some of those ketshup packets left over from last time.






I may use the occasional big word or don some yuppy threads, but my favorite way to enjoy a burger is to sit in the car in the parking lot listening to the radio. I was blown away once when She suggested, without my prompting, to eat in the car---ghetto style! See, despite our differences...well, She was a real down to earth lady and we got along really well.





I brought this Season All clone from the 99 cent store with me as a joke once when I met my sister at Pete's. Somehow or other it stayed in my truck, though, and lo and behold I just happened to remember I had it with me! Oh, so good on fries!






Now how can you say no to that?! None of that fake shredded lettuce they use at McDonald's. No giant multiple beef patties to throw off the delicate balance that all the ingedients contribute to that magical burger flavor.

...and yes, extra onions after all.

The Fields Are Ripe...and Empty

At Play in the Fields of the Lord was very sad and depressing. In the tradition of Heart of Darkness and Lord of the Flies, it features a couple of missionary families and assorted characters devolving into the most base elements of their persons under the mysterious, soul-denuding powers of the jungle canopy. That the author skewers the characters' faiths, cultures, dreams, motivations and all that they hold dear is all well and good, but what, then, does he leave us with? The book does end with a dubious redemption of sorts where the one "pure of heart" character comes out the other side with a sort of vague, primitive understanding of himself and nature. And what exactly did he come to understand? I dunno. I came away feeling the author thinks a zen-like embracing of nothingness is the pinnacle of enlightenment. How sad.

To be sure, this is a very challenging book and there's a lot that went over my head. Even so, it doesn't help that the author indulges a bit too much in psychedelic drug induced, disease induced flights of fancy to reveal to us characters' spiritual revelations. Now, I suppose this imperfect device is as good as any for describing such admittedly ethereal phenomena, but after a while it just comes off as a little pretentious and heavy-handed. You get the feeling you're listening to a stoned guy's gibberish--gibberish which the stoner sees as nothing less than God's word revealed.

I need to read some critical work about the book. I might change my mind.

Burger Therapy

I wasn't feeling too well this evening so I went out to get myself a cheeseburger. I feel much better now!

Itchy Compulsion

Gosh I wish gasoline wasn't so expensive. I'm feeling the itchy compulsion to drive somewhere--anywhere far. If money were no object and I didn't have to be back here by 6am I think I would drive out to the desert somewhere. I would go visit Xxyzx Road near Bakersfield, CA, home of the Tallest Thermometer where I almost landed my Cesna 172 at the wrong airport. I would take my picture next to the road sign, buy a bag of McDonalds cheeseburgers, park off to the side of some nameless dirt road and commune with the stars, the night, myself, my cheeseburgers...and God. That's what I would do.

But it's getting late and it's time for me to sleep instead. (For the poetically challenged, that was intended ironically, i.e. that it's getting late is, perhaps, more the reason to sleep no longer.)