CV Joint Failure Carnage

[ohecht]

Doing about 50 in 3rd gear when the inner driver CV joint let go and took out the throttle linkage, brake vacuum booster line, and CHT sensor cables. I haven't even jacked it up yet for a full inspection since I just got it home last night. Just stuck the camera under there this morning.

Not sure if the bolts sheared or backed out, but there were no advance warning sounds and I was not on the throttle that hard.

The piece of metal wrapped around the axle is the throttle linkage pivot, and I assume the mount for it was ripped from the transmission...does anyone have a part number on that rod that mounts to the tranny and holds the throttle pivot?

Olivier, in for some ugly assessment and repair...

[cmonref]

Wow! Yours is the unlucky version -- mine was lucky. 60 mph, downhill on Chippenham turnpike at Midlothian so no power on, and a big rattle. All six bolts backed out, no collateral damage. Thorough inspection and bolted it back up and drove away. There was no warning at all -- no rattle, bump, nothing as the bolts backed out.

Oh, yea -- mine was the inner right side, so fewer things to "get wrapped around the axle" with.

[pyro57]

This same thing happened to me on Friday (without the damage).
I was coming off of the freeway doing about 15mph. Three bolts gone, one broken and two bent. make sure you check the mounting point to the transaxle for cracks or damage.

Good luck, Dave

[osidak]

Happened to me in a parking lot - Was just starting to pull away when I heard a very bad sounding thump - WHACK

Stopped the car and looked underneath. Two bolts sheared and the others had back out.

Tried fixing it in the parking lot (was a sears after all) but between the black top being scalding ass hot and the sheared bolts I had to get it towed home.

I think you got lucky on the damage front - I have seen some nasty bits of mangled metal after that happens

[kcf7z]

UNfortunately - I have had this happen too. Throttle linkage and heat exchanger suffered but otherwise no significant damage - Scary as hell though when it happens and the throttle linkage goes accompanied but a thud.

Good luck to you.

[kqw]

Oliver...

Were the CV's recently R&R'd?

It looks like the bolts backed themselves out.....

[Gunter]

Judging by the amount of grease around the area, the bolts backed out, allowing the grease to be thrown out long before a complete disconnect.
Hopefully no major damage.
A few people will be encouraged to inspect their CV bolts after seeing the pix.

[KTL]

Happened to a buddy during a DE @ Gingerman. Same result. Spaghetti throttle linkage.

What's that hose shown in the picture? I'm not talking about the clutch cable.

[Nine9six]

Hmmm,
Drilling the CV joint fasteners for safety wiring may not be a bad idea!

[2.7RACER]

Sorry to see the damage. This sure is a warning for us to check the CV bolts for proper torque. There has been much discussion about proper torque and using Schnoor washers, etc.
Bottom line when you fix this use new bolts and washers, torque to specs and then check after fifty miles and recheck after a week or so.
The part number for the pivot pin is 914-301-307-00.
The lever is P/n 911-423-017-01.
You may need a easyout to remove the broken threaded end of the pivot pin from the transaxle.
The pivot pin is a porsche part. I replaced mine with a metric bolt and a bushing. Been good for a couple years.

[ianc]

Yep, this just happened to me last Fri, but I guess I was the luckiest of all. I had just changed all the joints out a couple weeks earlier. Drove home the 16 miles on the freeway after work, then stopped at Trader Joes for some beer. I was about halfway home (about a mile from my house) and stopped at a light. The light changes, I put in the clutch, engage first and let out the clutch and nothing. I knew right away what it had to be. I pushed it over to the side of the road, went across the street to the handy dandy repair shop there, borrowed a 6 mm allen wrench and managed (with one hand) to get the joint back on the flange and all the bolts snugged up enough to limp home. Many choice indelicacies were uttered, shocking passers by. They had just backed out though and the threads weren't even damaged. Phew! The throttle rod got slightly bent when I pushed it to the side of the road, so the throttle stuck a little, but I bent it back. It had flung some grease around, so I took it back to my buddy's shop, loosened that joint again, fitted a new gasket, packed more grease, and torqued the absolute crap out of it. Those bolts are hardened, so don't be afraid to really tighten the bejesus out of them. I think you will strip out the allen cap before you break them.

I think it's important to check them again after a week or so since the gasket will slowly compress and take some of the tension out of the bolts. Why did they want to use a gasket there anyway? It makes no sense...

ianc

[Zeke]

Originally posted by ianc
Why did they want to use a gasket there anyway? It makes no sense...

ianc

Wow. How many in one week? That's ridiculous. And, if you use safety wire, I would think that you would not want to put it on until you've retightened the bolts for about the 2nd time. You would only be holding them "loose" given the compression of the gasket. Time for some copper gaskets.

[jstein]

Well, here's my fiasco.

Happened in the breaking zone before turn 1 at Gingerman a couple of weeks ago. The noise scared the crap out of me.

Same deal - half shaft fell off of the tranny side - decided to bounce around and bring the throttle linkage with it...






Output flange. Two bolts donated their threads to try and get me some decent lap times...




Bell crank pivot stud left some threads behind too. A right angle drill, Easy Out, and a prayer to the car gods got this bit of metal out.




Throttle "linkage" remains.




Even the pieces in the engine compartment were not spared...




Maybe it's time to start a support group?

"Hi, my name is Josh, and I didn't check my CV bolts"

[kqw]

Alright, Alright, Alright...Already...

This evening I'm going to jack up the car and re-torque the CV bolts as 2 months ago I replace a CV boot.....

Thanks for the SCARE....I hate you guys...NOT.........

Another reason to get into the garage

[ohecht]

Wow!, I had no idea it was that common. I R&R'd all the CVs a while ago and they were out for a clutch job, but I always use new bolts, Schnoor washers, and I do check them whenever I am under the car, which is fairly regularly. I always thought I would get some sort of warning before such a total failure without trying to spin out or something. Makes it kind of hard to trust the car again if I am afraid to hit the gas...

I might add red loctite to the threads for some piece of mind, and just take the time to get a good tool and angle on the bolts whenever I remove them...

Thanks for the parts numbers and the feeling that I am not the only one this unlucky.

KTL, the large hose is the vacuum hose for the brake booster. I had the CHT sensor wires (metal) wrapped around it and the axle must have caught those wires first and then ripped out the hose.

I think the grease was just after the catastrophic failure, since I would have noticed it burning off the exchangers if it was flinging for any period of time.

Olivier

[MovOvr1]

have people safety threaded these for added security? Does anyone sell the bolts predrilled? That would be well worth doing.

Glad to here that everything is replaceable and there wasn't any further damage.....or carnage.

B

[jbrinkley]

these thread make people like me buy a scissor lift, because if you read enough, you'll be checking everything all the time. Jack it up after every drive and check the baby just so you can sleep well at night.
I think I'm about one more "check this or you car will die thread" away from getting a lift.
put me down for one that's never put a wrench on my half shafts

[randywebb]

There have been maybe a dozen reports of these things coming loose. OTOH, there are several thousand people on the bbs, so...

I tried to start a thread to findout _why_ they coming loose - of the few who posted it was:
a. not cleaning grease off the threads before installation
b. not torquing them down correctly
c. re-using old Schnorr washers instead of getting new ones (which have sharp teeth to bit into the substrate metal)

You can buy cap screws from specialty firms that have holes for safety wire manufactured in them. Be sure to get the right strength class....

Drilling your own holes is a lot of work, and I'd don't like hte idea of introducing stress risers where the cap might break off -- but Jim Sims said it should be ok, and he should know.

Hit the search engine and you'll find a lot of info on this. The above is a summary.

[hoosierdaddy]

What are the torque specs for these bolts and is there a certain pattern to follow when checking these bolts ?

[iamchappy]

I mark my bolts with a paint line and inspect often. I had a CV come off on me once. Without safety wire at least I can tell with a quick look if they have loosened up.