I think my transmission just exploded.
 

Took the car out for her second drive for this year, after all the work I did this winter on her interior etc I was feeling really happy with the car - and then everything just turned up-side-down :(

As I shifted from second to third, there was a nasty bang followed by a metal against metal banging sound. I killed the engine and pulled into the side of the road to investigate.

All looks OK from the outside, and the engine starts and runs with no problems. The clutch feels OK as normal, and I can shift between the gears. But the gears are not engaging at all. When the car is moved I get the same metal against metal knocking sound which is coming from the transmission area...

Not a fun way to start the Porsche season :(

My heart is foolishly hoping this is a cheap and relatively simple fix like the clutch, but my head is saying trashed 915 with a heavy rebuild cost!!!

Any thoughts out there from the experts?

Have you taken a look underneath the car yet? Any holes/leaks in the transmission case? I had nearly the same thing happen to me a few months ago. Turned out that the left axle had come off of the transmission and was hanging. The "bang" was the shaft hitting as it swung around. Cost me about $280 to fix (shaft, bolts and LOTS of Loctite). I hope it turns out to be a cheap fix for you.

Nope, not been under the car yet - I need some time to relax and build up energy to fix it...
I did have a look under the car when it happened, and could not see anything unusual.

you sort of have to get really way down and look back up towards the transaxle output to see if the shafts have come off or not....

If it is the axle make sure you replace all the bolts on both sides otherwise it will let go again. As I found out more than once.

Michael

sounds like a broken cv joint or an axle fell off.

Here is the definitive thread on this subject:

http://forums.pelicanparts.com/porsche-911-technical-forum/222537-reconstructing-constant-velocity-cv-joints.html

While long, this thread is worth serious study.

Best,
Grady

That sounds like what happened when one of my axles failed. The splines on the axle which hold the CV joint in place were rusted, and the CV joint slipped and stripped off the splines. I was getting ready to drop the engine and tranny before I finally noticed that a wheel was moving while it's axle was not.

Thank you all for the good replies. I decided to stay away from the car yesterday as it was just making me upset, and we had planed a nice family bbq for the afternoon.

I got up early this morning with a fresh mind ready to investigate, and as you have all already predicted - my transmission is fine. This is what I found as soon as I lifted up the rear of the car and had a closer look :)

http://forums.pelicanparts.com/uploa...1272691240.jpg

I cleaned and repacked my CV's when I did the suspension work 2 winters back. I did the installation as defined by Porsche and checked them again twice during last year to make sure all was good, so this reay took me by surprise...

Did the bolts shear or did they just back out?

My 914 did the same thing. Turns out the bolts backed out(I had just put the engine and trans back in after a top end job).

I drilled and safety-wired the bolts after that incident:D

Should there not have been washers and plates under the bolts? Are the bolts of the correct quality?

Been there for sure.
When it happened to me on a crowded freeway in rushhour traffic, it was not a fun experience.

Cruising at about 65mph in heavy traffic, then a big bang....followed by a terrific amount of noise in the back.
Oh yeah, and the engine was revving to the moon (throttle linkage was all torn up under the car).
Somehow I got the car over to the side of the road....coasting because I killed the ignition almost immediately.
The flailing CV put a huge gash in the SSI, sheared off the throttle support on the side of the gearbox, and mangled a number of other things it could get it's hands on.

For me, it was a pricey incident.
Hopefully, you have a lot less damage.

Exact same thing happened on my SC and two of my friends SC's... Great motor though :-)

They backed out. As far as I can see there is no real damage done.

One irritating thing is that I have the Stage8 locking CV bolts on order - Wish I had received them and installed them before now!

Obviously I will have to remove the axle and clean it all up. This is one of the jobs I hate the most, so I will use this as an excuse to get myself new axles and be done with it :)

I have the car booked in for a full alignment and corner balance next Thursday which I do not want to cancel. I also will not be able to get the replacement axles and install them in time, so my plan is to just put it all together limp to the alignment and limp back home - park up the car and hope I can get the axles delivered and installed (with the Stage8 bolts) before my first scheduled track session :)

I am just glad the transmission is all OK!

Hard to make out on the picture, but there are washers there. These are the correct bolts, as ordered from our host when I did the work last winter...

Glad it's going to be a "cheap" fix for you. When I read your thread, that's exactly what came to mind. I had used the correct bolts when I a did a repack and the CV boots this winter. I guess I must have gotten a little grease on the threads as I put them back in. I just used a little Blue Loctite on the threads after cleaning them for the reinstall. Now I get under the car at least once a week and check the bolts on both sides (probably should have been doing that in the first place). I'm thinking that the safety wire idea may be a good one.

Yes, in theory it ended up a lot cheaper than it could have been.

But as I have now convinced myself to purchase two new axles rather than having to go threw the cleaning and grease packing project from hell again, it will cost me a bit more ;)

Having had this experience, I am now really glad I decided to order the Stage8 bolts. Just wish they would have been delivered on time and not been delayed - as I would have already swapped the bolts out by now.

I think i'll go spend some precious time in the garage today and re torque my axle bolts !
I replaced all four rubber boots last Summer and installed new bolts from our host but after reading this post i'll put the odds on my side ... lol

Cheers !
Phil

This happens quite a bit, just be glad you were just cruising around and not into some real spirited driving at the time.

After any CV joint work, it is good to re-check them after the first drive.. then in a week, then in a month. I still check it yearly as part of a normal inspection.

Wow, I have just meet Mr. Porsche Tax and he was not a nice person :)

As I said, I will be replacing both my axles for new ones like these from our host for $267.75 - I would order them from Pelican if the shipping to Sweden and the import tax would not make the end price so high.

I have found a supplier locally that can supply them for 3152SKr (that's $434 in your local money). Now I know this is close to 50% more than from Pelican, but still cheaper once you calculate in the shipping etc to Sweden.

But here is the shocker! I decided to contact our local Porsche centre to see what the price would be from them - as they are close and I could collect! How does just over 12000SKr each sound to you - yes that is $1650 a side!

I pointed out to them the price from Pelican and the other supplier I found in Sweden, and the answer I got back was "can not be original Porsche parts, the quality is probably not as good as the ones we supply"... I am shocked!!!

Have you thought about replacing just the CV joints and not the axles?

Yes I have, but as the axles are now rather old (30+ years), and have some rust on them I fancy replacing all of it for new.

I did make a note when I reconditioned them last time that I would replace them some time in the near future as they were starting to look old - looks like that time has come ;)

Any one traveling over to Europe some time soon and fancy bringing two axles in their bag for me :D

CV joints are either good or they are not. I am assuming you are repacking and reassembling the old units until you replace them. If you get them together and they are silent, they will be good indefinitely.

Replace the faulty bolts and make sure you torque everything to spec. No need to throw the baby out with the bath water.

Hi Daniel, I will assume based on your posting that you have not read threw the complete discussion...

I already have Stage8 locking bolts on order. They should have been here by now and will have prevented this from happening, but they have been delayed.

I will patch things up to get to a already booked corner weight and alignment session on Thursday. With two small children and a full-time job, I do not have time to remove the axle, clean it all up and pack the CV joints again before Thursday + the centre where I am booked in has a VERY long lead time, and I want the alignment done asap.

The CV joints and the axles are old. When I last did the CV joints, there was substantial rust and corrosion on the axles - enough for me to decide I would change them soon. The CV's were also starting to show their age, but I decided to try and get at least one or two more seasons use out of them.

I am using this as a reason to install new axles with Stage8 bolts. I will probably clean up the old ones and keep as spare...

Interesting thread.
I will be replacing the CV bolts soon in my '80 SC.
Where do I get the Stage8 bolts you will be using?
Thanks in advance.

Where are you located - US or Europe?

What are the torque specs for the axle bolts?

M-8 30 ft/lbs, M0-10 60 ft/lbs. For a 78-83SC.

I am in Florida, USA
Also, what advantage do the Series8 offer?
Thanks

As our host does not stock these, I am sure it is OK to list suppliers?

In the US, you can get these from here, and in Europe from me.

The benefit of the Stage8 bolts is that they integrate a locking system that prevents the bolts from backing out once installed, like this -

http://www.stage8.com/images/perfparts.jpg

Got it !
Thanks very much for prompt reply.

This is pure BS.

If new CV joints are properly serviced and maintained (like....once per year cleaned and inspected and repacked using high quality hign pressure moly grease), then I'd guess they could last a LONG time. But unfortunately, most joints have not been properly serviced. I've looked at a fair number of CV joints from 911's, and they are rarely in the condition I would call "excellent." I'm not sure I've ever seen one in that condition. I've seen a few "decent/useable" condition ones, and a LOT of "unacceptable" ones. Very few "good" or "excellent."

I know that, and you know that. But the Porsche dealer in Stockholm would like us to think different...

Agree 100%, and mine were usable the last time I serviced them.

My new axles arrived today :)

Took some time during lunch today to have a closer look at my new axles. In all, they look nice and new and shiny, but I was not 100% happy with the way they had been packed up for shipping.

There was just some paper used at each end, and that was not good enough to keep them in place, so when I opened the boxes, the covers had come off the CV joints and there was grease everywhere :(

http://forums.pelicanparts.com/uploa...1273235691.jpg

I gave them a good clean and inspected them for damage. They look good and ready for installation...

But I have one question, and I have had the same problem the other times I have installed the axles - how in hell do you install these and make sure every bolt is clean and has no grease on them :confused:

I am not really willing to clean the CV joint holes with anything as I do not want to contaminate the grease in the CV - so there is no real way to make sure there is NO grease in the mounting holes (especial now after the crap packing done by the factory!!!

I would spray the bolt, once penetrated the CV with brake cleaner. Use a rag to make sure it doesn't mix with the grease.

Doug

I am sorry Doug, I am having problems visualizing you suggestion. Could you elaborate a bit further?

I actually have one more question. When I look closer at the new axles, I noticed that one of them is not the same as the other one - they both have the same part number, but on one of the axles one CV has s different end with a gasket already installed into a slight recess, which is not on any of the other ends.

What is this all about :confused:

http://forums.pelicanparts.com/uploa...1273249645.jpg

http://forums.pelicanparts.com/uploa...1273249700.jpg

These axles are to go on my 1978 SC, is one of the not correct? I have also received 4 gaskets separately in a bag. If the end of the CV does not have a grove in it, should the gasket still be used?

It is such a long time since I had my other axles off the car I can not remember what they look like - I do know I had to use gaskets to install them!

What i did was install the axle and all bolts (just snug them up for now) then remove them one at a time, spray some blake clean in the hole, clean the bolts and reassemble.
The gaskets should fit in the wheel/trans. flange and also between the CV boot and CV.