Thud from the rear after quick acceleration, now I have issues...

[Sdgg91]

Originally Posted by gomezoneill

I have no doubt that it's related. The circlip may have popped off that holds the cv to the shaft. I would be pretty confident that it will be simpler than you think.

I sure hope so!

I may just bite the bullet and buy two brand new axels and call it a day if that痴 the case.

Beats anything transmission related from a $$ perspective.


Sent from my iPhone using Tapatalk

[Sdgg91]

Originally Posted by Sboxin

Sh . . . it happens . . . and tooth slid from diff housing into 5th gear nose and locked up shifter . . .
But, I am more in agreement with others that CV might be the problem or clutch . . . hopefully not the trans . . . in any case I would not drive the car . . .

Regards,
Roy T

That is some serious carnage!...


Sent from my iPhone using Tapatalk

[Mahler9th]

I have seen ring and pinion parts like that before. Including my own.

Anyway, like others here, I hope it is something ez to identify and deal with... crossing my fingers.

[Sdgg91]

So I pulled both axels off tonight.

I did as everyone suggested (and a big thanks to everyone who has chimed in with suggestions!).

I inspected both CVs and the circlips were still in place, however the new CV that I put in there is really stiff and doesn稚 move very freely especially compared to the other three CV joints fly. After spinning the wheels and e the opposite side spin in the reverse I wasn稚 able to replicate the exact noise.

I did there is a lot of play in the (and excuse my non technical term for it) differential hub where the six bolts screw into the diff and attach the cv to the diff. When holding the hub and moving left and right there does feel like some slack there, almost like the center bolt that holds the hub to the diff is loose or has some play.

My plan is to just order new axels, install them and see if that fixes everything. Might as well start with the cheaper stuff that I can finish in my garage before taking it in.

https://youtu.be/i3FwBummmfE

[gomezoneill]

Good luck hope its the CV not the Diff.

[Sdgg91]

Originally Posted by gomezoneill

Good luck hope its the CV not the Diff.

Same... thank you.


Sent from my iPhone using Tapatalk

[Sdgg91]

So hypothetically if I did assemble the one joint incorrectly, and drove about 200 miles on the car.

Could that have damaged something in the diff/tranny?

[Solamar]

I dont know if Porsche was still using the (failure prone)rubber centered clutch discs with the G50 trans, but if so, that would be my guess.

[Mahler9th]

New CV joints can be stiff-- they need to be broken in. If you have confirmed proper assembly, then the CV axle area is unlikely to be related to your issue(s).

I am not familiar with the G50 transmission output flanges. If they are similar in design to the 915, there will be a center bolt that holds them to the diff. Again, I have not serviced a G50, but here are some things I can think to check:

You could perhaps drain the transmission lubricant and inspect the drain plug magnet if present.

You can remove the transmission output flanges and inspect them. If the G50 is like the 915, you'd have to at least partially drain the tranny to do so.

If the G50 is like the 915, once you have the CV inners disconnected and the flanges removed from the tranny, it might be trivial to remove the transmission cover plate and inspect the diff, ring and pinion.

If you are a DIY-oriented person and just learning, it might be helpful to have some documentation with steps and drawings. I have used Haynes, Bentley and factory workshop documentation during my ~30 or so years working on my various Porsches. It has been very rewarding and has saved me a lot of money.

Of course the easiest thing to do is to use the services of a local shop with experienced experts. I live in a place where these are in abundance.

Anyway, I am not sure if new axles are a good investment at this point. I would recommend studying a bit more or just accessing local expertise.

[Sdgg91]

Originally Posted by Mahler9th

New CV joints can be stiff-- they need to be broken in. If you have confirmed proper assembly, then the CV axle area is unlikely to be related to your issue(s).

I am not familiar with the G50 transmission output flanges. If they are similar in design to the 915, there will be a center bolt that holds them to the diff. Again, I have not serviced a G50, but here are some things I can think to check:

You could perhaps drain the transmission lubricant and inspect the drain plug magnet if present.

You can remove the transmission output flanges and inspect them. If the G50 is like the 915, you'd have to at least partially drain the tranny to do so.

If the G50 is like the 915, once you have the CV inners disconnected and the flanges removed from the tranny, it might be trivial to remove the transmission cover plate and inspect the diff, ring and pinion.

If you are a DIY-oriented person and just learning, it might be helpful to have some documentation with steps and drawings. I have used Haynes, Bentley and factory workshop documentation during my ~30 or so years working on my various Porsches. It has been very rewarding and has saved me a lot of money.

Of course the easiest thing to do is to use the services of a local shop with experienced experts. I live in a place where these are in abundance.

Anyway, I am not sure if new axles are a good investment at this point. I would recommend studying a bit more or just accessing local expertise.

I guess for practice I am going to redo the CV and repack it with redline c2. I知 hearing the stuff that comes with GNK Isn稚 that great.

The new CV still moves around And pivots although does feel very notchy. Is there a sure fire way to know if the CV Is assembled right? I made sure to study all or the drawings lining up the skinny to wide orientation and thought I nailed it on both sides. Also the CV went together fairly easily.


Sent from my iPhone using Tapatalk

[icarp]

Sam , A good practice item would be to remove the engine and trans . I think the answer lies in the clutch.
What you will learn will blow your mind and make you happy.
You can do it !
Call me if you like
Ian

[porsche930dude]

my guess is a problem with the spider gears not the r&p because it is in gear when the clunk occurs

[famoroso]

My money is on clutch disc rubber center failure...



See post failure video here: https://www.instagram.com/p/B9tB20dF6qv/?igshid=44g229hc9j5d

I had a thunk going into and out of gear as well as on and off throttle while in gear.

LMK what I win. ;-) Hopefully, it's a new clutch. I kid. Already replaced mine with a spring centered version.

[gomezoneill]

Those clutch discs were a dumb idea.

[Sboxin]

Ah Ha !! Got it . . .

Got have a sense of humor . . .

Regards,
Roy T

[juanbenae]

all the CV's ive worked with on my two cars if assembled wrong it's very clear from the outset on the work bench.

[manbridge 74]

Yes, usually you can’t flex them at all when assembled incorrectly.

One thing I like to do is clock the CVs end to end on the axle. Meaning an opening in the star piece should not line up with an opening at other end of axle. This is how they were new but hardly anyone does it at rebuild. Google “clocking 930 CV joint” as the off road guys do it...

Not sure what your issue truly is but this WAS the last thing you looked at... where the problem almost always is. Sounds like you might have a bad CV...

[Sdgg91]

Originally Posted by juanbenae

all the CV's ive worked with on my two cars if assembled wrong it's very clear from the outset on the work bench.

Yep I知 100% sure everything is together and functioning properly after double checking things today.

I知 taking it to mayo performance in Dallas this week. The symptoms I have are identical to others who have experienced the rubber center of the clutch failing. And it went out after a spirited launch similar to others who experienced the same Failure. I will keep everyone posted!

An engine/tranny drop is outside of my comfort zone right now, but probably some day I値l take it on.

Once I get passed this I have poly gold bearings and adjustable sway away spring plates along with a cat less pre muffler that I知 going to put on her.. this is just a speed bump along the way.

Can稚 wait to get her back on the road.

[Sdgg91]

Originally Posted by famoroso

My money is on clutch disc rubber center failure...



See post failure video here: https://www.instagram.com/p/B9tB20dF6qv/?igshid=44g229hc9j5d

I had a thunk going into and out of gear as well as on and off throttle while in gear.

LMK what I win. ;-) Hopefully, it's a new clutch. I kid. Already replaced mine with a spring centered version.

These are my EXACT symptoms.. happened after a spirited launch too. I値l bet your right!


Sent from my iPhone using Tapatalk

[76FJ55]

The guys at Mayo are a great crew, they'll get you fixed up for sure. Are you in the DFW area? I'm in Grapevine. They have (or at least before the Covid days) a 3rd Saturday Porsches and coffee there every month. Always a good time if you get an opportunity to attend.