Loud BANG then...
 

As the title says, I was running errands today and approaching an intersection, slowing then starting to speed up, a horrendous BANG then no traction. Engine revs up, clutch pedal feels normal, gear shift feels normal. No funny noises or anything.
Towed to shop, one of the mechanics thinks clutch cable, but I don't think so. My retired Porsche mechanic buddy (30 years experience) thinks an axle snapped. I'll know Monday.

I just picked it up yesterday after they replaced the engine mounts.

Any thoughts?

Thanks

i suggest you don't want a mechanic that thinks it's a clutch cable. there is no clutch cable.

I would suspect an axle. As stated above, the clutch is hydraulic, so no cable.

+2 for axle.

Shot in the dark - shifter cable popped off the trans.

A snapped shift cable wouldn't make a BANG...?

Bang
 

It's been a very long time since I worked on Porsches. I will need to look at some service lit. My buddy said something about one shaft is driven and it drives the other. idk.

The guy who made the cable comment is just one of the monkeys, no disrespect intended.

Dave, the owner knows his stuff, as do his the other mechanics. He has a 5 star shop and has 100K invested in in diagnostic and mentioned $12K/yr subscription (this must be PIWIS). I trust him.

I took the car to him evaluate with the intent of doing IMSB, but he said he did not recommend it, that the car sounded fine and was in great shape. They did replace the engine mounts and the plugs and one tube was leaking.

I'll know Monday.

Thanks for your feedback.

btw can someone explain how i can list my cars in the message box?
thx

In the user CP you can set a signature...

Something could have gone wrong during the engine mount change. Don't they have to drop the engine a few inches? The other possibility is the clutch disc.

I agree on the Axle. I used to drag race air cooled VWs. CV joints love to pop, especially when the boots fall apart from age, blow all their grease out, then start collecting dust and dirt in them.

A good indicator to a CV going out is a clicking or clunking sound while going into corners, or taking off from a dead stop.

Doubtful. The engine has to move a tiny bit, unless someone has no idea what they are doing. It’s a straight forward job.

Regarding the IMS, if you are taking out the tranny for some reason do it, as well as the clutch, and RMS. The primary labor is simply accessing these things. I think the IMS thing is real, but hyped for sure. But, if I were ever needing to have the tranny removed, it would get done.

I vote axle as well. Not sure what was meant by “one axle drives another etc” odd...

BTW, if an axle it’s very easy to diagnose. Like get it up in the air and look...

I suspect what he was talking about was the open differential. For those who may not understand that, in an open differential, if one wheel is in the air, it will Spin and spin and spin and the other wheel will not turn.
Likewise, if one axle is broken, the shaft will Spin and spin and spin and no power will be applied to the other wheel. In other words, breaking one axle is as good as breaking both axles! :-) haha

Given the bang, and then the lack of any other noises afterwards, I would also vote for the axle. There are things that could go on in the clutch, or in the transmission itself, which could cause the symptoms you are experiencing, but you would most certainly hear things rattling around now.

And as has also already been said, you should be able to diagnose that very quickly, just by peering underneath the car.

Sent from my SM-G930T using Tapatalk

+ one more vote for an axle/cv joint that failed.. :p

Additional input
 

Thanks for the comments guys. I'll hear from them tomorrow. I agree with maytag and Gilles, but hope it's not too major.
The previous owner recently had the clutch and pilot bearing replaced.

We are all just speculating, aren't we? I hear improperly torqued axle bolts can be problematic.

+1 Axle bolts.

Doubtful it’s the motor mount...

Yeah, he could have been talking about the diff... just an odd description if so. But I suppose in “lay” terms it would make sense to describe it like that.

Bang
 

356guy, 911monty - Axle bolts a possibility, as the previous shop r/r trans to do clutch, but what went bang is the question. Thanks again for comments.

Check out this old post:
http://986forum.com/forums/boxster-general-discussions/54453-lost-all-gears-my-2001-boxster-today-help.html

Bang
 

Thanks 78F350. I think mine might have the same. Did not hear from the shop yesterday, keeping my fingers crossed.

I had the rear wheel bearings replaced and the mechanic didn't torque the axel bolts properly (actually think he barely hand tightened them) and I dropped an axel. Same noise, same result.

mechanic had to remove transmission to r&r clutch, etc.

requires disconnecting axles from flanges at transmission.

when reinstalling, the bolts that fasten the axles to the transmission flanges have to pass through the inner cv joints.

in the process of passing through the cv they pick up grease and don't hold torque.

as you drive they slowly back off and fall out until only one or two are left.

remaining bolts shear as they are not strong enough to manage the torque transfer from transmission to axle.

axle lets go and bangs around underside of car making lots of noise and doing damage.

flange on that side now spins freely as not connected to axle any more.

given you have an open differential, no load on one side means no drive to the other.

no matter what gear you choose, nothing happens.

Bang
 

Thanks Radium King.
That explains a lot.
The clutch job was done 2 years ago, so plenty of time to work loose.
I think I dodged underside damage, as it happened as I was slowing in approach to an intersection, doing about 30mph, then started to accelerate. After the bang, I must have only traveled less than 20 feet.

Would the axle bolts give any warning? Would it clunk around a bit prior to popping off.
Is it a big fix?

DWBOX,
This hapen to me twice in two different cars and just re-installed and tighten the bolts (one time on the spot) as the bolts remained attached to the CV joint, the other time had to towed home as the remaining bolts sheared after a few got loose and fell into the ground.

Driver's side axle... Don't asks me how I know.

Same thing happened to me was my right inner cv joint. I have a tip and was noticing a bang when i put it in reverse, then as i was driving and when the trans downshifted.

Just heard from the shop. "broken axle". The inner CV exploded. He said the CV was just spinning around with its components loose inside, so may have damaged the spline. He is going to see if his machine shop can repair the axle. He'll let me know later if the axle needs replacing.

good. that's the least painful repair I could think of for your symptoms. :dance:

Tailwind,
Instead of repairing the axle, perhaps be way cheaper to get a used axle from Woody..

+1 maytag
Gilles, I've owned the car a week and a half, and the shop has had it longer than I.
I'm learning a lot about the 986, and am looking forward to some mods. Dave (my trusted mechanic) has a good reputation, and I don't want to second guess him. I could have changed the axle if I had seen this coming, knowing what I know now, thanks to members' input. Anyway, the case isn't closed, because Dave first said "we need to find an axle". I still need to hear back on the status.
Can you point me to Woody? If Dave says the shop cannot repair the axle, I can suggest it, thank you.
More to come...

Woody's Parts, LLC: 512-925-9171, Bastrop, TX.

i would advise against buying a non-oem axle. look to repairing your own or buying a used one from woody and rebuilding if necessary.

the damage to the splines may be par for the course; when i serviced my axle, i found that the inner cv had worked the axle a bit, marred the splines, and was quite difficult to get off. axle was still well reusable however, and the actual cv, boot, bands, are inexpensive.

lesson - keep an eye on your cv boots; clean and treat them annually.

[QUOTE lesson - keep an eye on your cv boots; clean and treat them annually.[/QUOTE]

This is a great idea.......probably the most critical rubber to address on the car........what do use to treat them? One would want to unduly degrade them boot with something that's not compatible.

Loosing the boots means a lot of work and expense

Just heard from Dave. No issue with the splines. Dave said that if the axle could not be rebuilt, they would have returned it.
They rebuilt the assembly with a Kolbenscmidt CV joint and it will be ready today.
I know Kolbenschmidt made pistons, but I can't find any citations about CV Joints.

Tailwind,

You meant Kolbenschmidt in Shanghai...?

Sorry, could not resist...

They sublet the rebuild of the axle replacing the inner CV. Runs great and tracks nicely, but now that I've had a chance to drive it more...man it rides like a buckboard. With 99K, I'm gonna do the shocks.
Since the nose has a lot of scoring/pitting, I want to get the nose painted (I have the Aero option on the car). I queried the mechanic about a nearby body shop, and he said "you have an old car. You should just drive it for a couple of months and see". The car has a few small dents and dings, but I won't address those right now, but don't want to drive it with the nose looking like that. It's a Porsche pride thing :)
The other "major" issue is there is a big hole in the outer driver side bolster. I'm looking at options.

Detail of nose lightened to show damage...

http://986forum.com/forums/uploads02/3a1542559674.jpg