Date: Mon, 30 Aug 2004 13:37:30 -0700
Reply-To: Tim King <yellowdog@SOFTHOME.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Tim King <yellowdog@SOFTHOME.NET>
Subject: SNAP! Zrrrrrrrrrrrrrrr! (sheared CV axle shaft)
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So, I'm minding my own business starting out from a stop in my van, and I hear the above mentioned very loud sound, and no longer can move (without difflock that is).
First thought is, Oh, no, not my tranny again. My buddy hops out, looks at under the van and says "you busted your CV joint."
I'm thinking that's weird because I just bought brand-new, rear CV axles (empi made from bus depot). He takes a closer look and says, "uh, the whole shaft broke!"
Yup, true tale. The driver side axle shaft sheared in half right under the tranny side boot. It looks like it was laser cut it's so smooth. Anyone ever seen this happen? Axle had about 300 miles on it. Van is a syncro Westy with suby 2.5. I'd like to blame this on the massive power (yeah, right) of the suby engine, but I think it's simply a defective axle.
Up until now (300 miles), I've been kind of disappointed with my suby conversion. I didn't really want to admit it, what with the added reliability, plenty of power, and really cool sucking sound of the K&N intake, who was I to complain. Still, the van just hasn't been smooth. It kind of felt jerky all the time. Almost like a massively binding VC (except that my driveshaft is out of the van). I thought it must be some kind of ignition miss (experienced during accel and decel, though I'd notice it out of gear, too), but nothing showed up on the OBD-2 software. Bad tires? Clogged exhaust? Tried diagnosing all of these things with no luck.
Then the shaft snapped. I borrowed my buddy's car (mmmm... heavily modified Audi S6), drove home (thought about leaving him with my broken van and keeping the Audi), and got one of my good old axles (note to self: this fits the "if ain't broke, don't fix it," rule -- I only installed the new axles because I wanted everything to be "fresh" following my conversion. The old axles were fine -- the boots were good, and the grease smelled fresh). I popped in the new axle and wow, it was a new van. It felt like it had more power, it was smooth, and I was VERY happy.
My theory is that the axle had a bend or crack in it from the beginning and was wobbling with every wheel rotation. That wobbling was the jerking I was feeling. There was nothing to see -- the crack was under the edge of the boot, so I don't think I ever would have found this until it broke.
Ah, I like my van again.
Now what to do about the axles? Anyone had any problems with the BD empi axles? Are they strong enough for syncro use? I measured them when I got them and I think they are about 1mm larger diameter than stock. What are the operational angles of the CV joints? (not that these 200 miles were any more stressful than driving around my neighborhood, but I'm thinking long term). I have stock springs, but I know lifted syncro drivers pay attention CV axle operating angles.
Love to hear some thoughts on this.
thanks.
Tim in Seattle
87 Syncro Westy, suby 2.5
PS -- Following the axle success, I installed my 225/75-15 Bridgestone Revos. I'll follow with a full report later, but these seem to be a very quiet, very stable AT tire. John at aircooled.net raves about these and I think he's right. At 28.3" I wouldn't recommend them for a stock waterboxer, but the suby handles them just fine.
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