I've been most fortunate over the years that the number of catastrophic mistakes I've made either working on my cars or home improvement projects have been minimal. I can't say they've been few and far between since with any project something's bound to go wrong but I'm usually able to work through them. I'm fond of saying that it's not really a "project" until something goes wrong. I say that in gest but there's a lot of truth to that.
One such incident I could not work my way through was recently when I was reassembling the rear end on our 1977 Corvette. It's not like I was sloppy or rushing things. In fact, the biggest and no doubt most expensive "oops" of my "DIY" career may have been because I was being unnecessarily thorough. Years of research, meticulous attention to detail and anticipation of what could go wrong can only do you so much good; when you make an honest, inexperienced or rookie mistake like breaking off the head of a bolt, like getting knocked down in life, it's how you react that's most important.
Yes. I broke a bolt - and an important one too. It was one of four bolts that secures the strut carrier to the bottom of the differential. If that sounds ambiguous - it's not. I thought I could get by with three bolts since the carrier itself is very heavy gauge iron but there's four there for a reason and three is not what the engineers called for. There's four to offset the tremendous torsional action on the rear struts that keep the camber and toe in proper alignment on the rear tires.
What happened was rather than simply tightening the bolts down "snuggly", I felt compelled to "torque-them-down" to eighty foot-pounds. The first bolt clicked at eighty without any fanfare but the next one, the one closest to the driver's left side rear wouldn't "click". So, I kept going and going until I finally did hear a click of sorts but it wasn't the satisfying "snick-snuck" of a torque wrench hitting it's desired spec. It was the snap of the head of the bolt.
I tried to shake it off at first like being startled awake by a bad dream. I don't remember if I went to torque another bolt down or not but I do recall thinking to my self that I should back that bolt out and put it back in; the head was still attached to the bolt. Y'know, to be "safe". I put my torque wrench in reverse and the head of the bolt came off in the socket. The rest of the bolt, threads and all, torqued deeply into the case of the differential.
It's only in retrospect that I can say for certain what I should have done next was certainly not what I actually did. What I should have done was pull the differential out and take it back to the shop that rebuilt it for me and have them try and get the bolt out. Nope - rather than do that I really complicated matters by attempting to get the damn thing out myself.
There are plenty of youtube videos showing you how to get a broken bolt out. A number of them involving broken bolts on the insides of engines too. Yikes. They're pretty interesting, informative and straight forward and of course, nothing ever goes wrong in them. In the videos that are posted at least. I'll cut to the chase - getting a broken bolt out is not for the faint of heart or inexperienced shade-tree, garage mechanics like me. It's something best left to professionals. Or at least someone who's done it before on something that's not as expensive and important as an automobile differential.
To make a long story short, after failing repeatedly to back the bolt out using a bolt extractor, failures that included the bolt extractor breaking off in what was left of the bolt, I punctured the differential case attempting to drill the bolt out. The gooey, sticky, smelly gear oil spilling out onto my drill like a tapped maple tree.
I experienced a heady combination of emotions as my freshly rebuilt differential slowly bled to death into a red rubber bucket in my garage. My garage filling up with the obnoxious aroma of 80-90 weight gear oil that smells like sweat socks left to bake in a hamper for a week or more. Crestfallen, humiliated and frustrated, I marched into my house screaming my head off. My wife, bless her heart, was great about it. Hearing me yell as loudly as I did she thought I had chopped off a finger or worse. When she realized it wasn't that bad she all but shrugged off what had happened. At the time I certainly wished for damage to an appendage of mine rather than face the onerous task of remedying a massive "eff-up".
At the time of course she had no idea what had happened or what an ordeal it would be to be fix it. At that point I wanted to push the the entire pile-of-junk into Lake Erie but that was impossible since it had no rear wheels. I knew the differential case or carrier was toast and replacing it was going to be expensive and time-consuming. Online, differentials for our car run from just under a thousand dollars for ones that still need stub axles and a rear cover for just shy of two-grand for a complete assembly. Even an empty case like I busted runs about $700 and that's one that doesn't anything inside it. To say I was "screwed" was an understatement. And, no, my swapping the gears into another case was out of the question; a man's got to know his limits. I resorted to that great online garage sale shit show known as Craigslist. And hit pay dirt.
I found a complete assembly north of Detroit for next to nothing that the owner, a suspension engineer for Ford of all things, claimed came out of a '73. It seemed ok but honestly I really didn't know. I had my doubts but the case was solid and that's what, at the end of the day, I really needed. I did my best to try and determine if the half shafts or stub axle tolerances were ok and what not but it's hard to tell. Best thing I did was swallow my pride and take both differentials back to the shop that did the initial rebuild and fall on their mercy. Sure enough, they said the "new" differential I bought was "on-it's-way-out", but of course, and for a not unreasonable sum, they swapped the gears from my punctured, ruined diff into the "new" one I bought up in Detroit.
So, now we're back to square one with a totally dismantled car sitting in my garage. I've been at this since mid-June but I finally see the light at the end of the tunnel. And I'll be damned if I make the same mistakes again. Let's go.
No comments:
Post a Comment