3.2 conversion - strong noise from new g50

[baruch mor]

Just started the engine after the conversion of 2.7+915 to 3.2+g50.
The engine started right away but there is strong noise from the gear/clutch when i press the pedal and cant shift into gear! the sound is mechanical...

the noise is only when u press the clutch pedal .

the transmission was at patrick motorsport and had a full rebuilt of the clutch , flywheel and gearing - all new parts ! never tried the gear/clutch before as i bought it in the USA and sent it directly to patrick motorsport that completly rebuilt my g50+short bell housing + new flywheel + new clutch.
here in israel i just added 75-90 gl5 oil and thats it.

Need your help there as don't know what to do now! cant take the tranny to patrick as I'm located in Israel!

please tell me where to start checking!

[baruch mor]

Please let me know if there is something that i can check right now as the car is at my mechanic and he thinks that something was installed bad at patrick or something is broken inside the clutch.

the noise is strong and only when i press the clutch pedal and cant shift to any gear!

i guess we need to drop the engine n split the engine from the tranny again to check or can i do something else?

can it be from the g50 shortening (short bell housing)?

[baruch mor]

ok engine is down - something is broken here !
in any case its going to cost a lot of $$$$!!!!

[KTL]

G50 is supposed to be noisy with clutch released, not with clutch depressed.

Everything is fixable. Show some pictures of the problem.

[CBRacerX]

Pictures will help.

[beepbeep]

Throwout bearing siezed or installed incorrectly?

[baruch mor]

ok so its one of the alum. parts ("ear") on the case of the gear that holds the clutch control shaft n the release fork. we didnt use the clutch too much only tried it twice so no damege to other parts - here r the pics:





the broken hear and its piece in my hand




it made a scratch/groove in the fork too


and a damege to the piece of plastic (?) here


and scratches all around the clutch plate (see the silver places on the orange )



Now my questions are:
1. what could cause it? how can i check that it wont happen again after i fix it?
2. can i alum. weld it? anything i must take into consideration?
3. anything i need to know?
4. is there something i need to know about how to install it back after welding?
5. who is the responsible here?

[CBRacerX]

This is a big problem. You will have to weld it then machine the trans back to rights - not easy. It appears that maybe either fit is off and when you bolted the engine and trans together you cracked the ear, or that extreme slave cylinder pressure against an immovable pp assembly broke it. Or there was an assembly error and the throwout bearing was not engaged with the lever properly and when you bolted it all down - crack. Or perhaps the lever pin was not installed all the way.

Sorry.

[baruch mor]

Originally Posted by CBRacerX

This is a big problem. You will have to weld it then machine the trans back to rights - not easy. It appears that maybe either fit is off and when you bolted the engine and trans together you cracked the ear, or that extreme slave cylinder pressure against an immovable pp assembly broke it. Or there was an assembly error and the throwout bearing was not engaged with the lever properly and when you bolted it all down - crack. Or perhaps the lever pin was not installed all the way.

Sorry.

thnaks for the fast answer CBRacerX
1. what do u mean machine the trans back to rights? and why its not easy? what is involved with it?
2. how can i check if there was an assembly error and the throwout bearing was not engaged with the lever properly ?

[CBRacerX]

Originally Posted by baruch mor

thnaks for the fast answer CBRacerX
1. what do u mean machine the trans back to rights?
2. how can i check if there was an assembly error and the throwout bearing was not engaged with the lever properly ?

1. After welding you will need to remachine the inner ear surface - it needs to be perfectly aligned with the other ear and sized for the pivot pin. Non-trivial.

2. This is really a basic step in the assembly of engine and trans, but if you have never done it before you need to be careful that everything is mating as it should. Look at the factory manual for this step - the lever is engaged with the bearing before assembly and hung on with tape.

[baruch mor]

thanks
i will take it tomorrow to a specialist ill let you know
should i live tick alum welding outside the ear or this is not necessary ?

[baruch mor]

one last question : must i change the needle sleeve? one is a bit damaged

[KTL]

Absolutely change the clutch fork sleeve. The fact that it's damaged means there was some binding in it.

The trans bellhousing pivot shaft ear breakage is unfortunately not that uncommon. Plus, when the ear is bored out for the updated shaft assembly, it removes material which can make it more prone to breakage. It can be welded back together if you have sizeable pieces. However if it is broken into small pieces, you're better of making a new ear with a block of alloy like California Motorsports does it- see picture at the very bottom of the page in link below

http://www.californiamotorsports.net/index.htm

[baruch mor]

Originally Posted by KTL

if it is broken into small pieces, you're better of making a new ear with a block of alloy like California Motorsports does it-
http://www.californiamotorsports.net/index.htm

thats what the welder did without telling him , made exelent job even better than original, think the problem was that when they closed the gear they did not push the lever pin all the way.

- also changed the fork sleeve with a used one in a good condition

how can i check that everything is ok before it will be brake again ?

[baruch mor]

can i use the fork of the 964 instead? i have one here that i can use . on the 964 there is the same number but in the books the number is different
they look the same n the mechanic told me it looks the same although the serial number is different

baruch

[KTL]

If you have the 964 fork and the old fork, you should be able to lay them side by side and check shapes/sizes of everything?

Check the shaft holes (plastic bushings that previously failed) in the fork to ensure they're the same

Check the bends and size of the fork fingers are the same.

Check the width of the fork at the shaft holes is same.

Check the pivot arm hole for the slave cylinder.


The 5 speed G50 transmissions from 87-94 (911 3.2 to 964) are basically the same except for some gearing changes and how the rear of the transmission mounts into the chassis. I think it's safe to assume the forks are interchangeable.

[baruch mor]

Originally Posted by KTL

Check the bends and size of the fork fingers are the same.

There is a slight difference in this section - but when i try it on "dry" on the clutch it looks ok - what do u think?

[KTL]

Check the thickness of the fork fingers to make sure you don't have clearance problems. John JL had a problem with a G50 fork that wasn't clearing his custom clutch. Do a search to confirm.

But I can say for certain that Porsche continually refined the fork to add strength to it, as early versions broke on occasion