As some may remember I've had my gearbox repaired. Main shaft bearing was shot. After a year and a half and 15k miles later I have similar noise again. However to be fair it worked fine within this period. It appears the second bearing has gone (After exhausting research I now know that there are two bearings on the main shaft) the second one being pressed into place hence replacing it is more difficult. I presume this is why my tech didn't change the second one. I also understand that getting clearances right is the tricky part. And this was proven in my case. The idiot in addition to not changing the second bearing introduced 2nd gear pop out into my gbox. I presume this is due to incorrect stacking of the clearances but thankfully detent fixed it.

I am going with a different tech now who is hopefully better. I simply can't find a Porsche tech here in Slovenia (where I am based now) to competently address this gbox for me. I mean common any gearbox specialist should be able to do this, it's not rocket science right?

I have a question, I know the gearbox can be taken out with engine in the car. The new tech tells me that the engine has to be dropped slightly and that the coolant needs to be released in order to get the gbox out? Is this so?

Just assessing his knowhow...

Ps. Anyone knows of a blueprint relating to our gbox? PDF file - clearances?

 

What were the symptoms that prompted this times removal/service?

 

yeah, if the guy is unaware of the updated clearance specs with shims to where 4th gear sits in the gear stack..? find someone who does. for real. my porsche dealer had to rebuild it twice back in 09 and they were *factory* and had all the updates at their desktop workshop manual. i guess they read it *sometimes* ... lol

 

correct on both points. drop the motor slightly by loosening the rear mounts. theres 2 water lines the run under and across the trans. clamp them on both sides and disconnect them. by removing the upper pass side mount stud the trans comes out much easier

 

You do not need to drain the coolant. I loosen the brackets that hold the hard lines to the under body and push them over to the side, no drain of coolant. When you replace bearing you will not need re shim the pinion shaft, the bearing are all clearanced the same. The second gear pop out could be as simple as the Guide sleeve 1st/2nd gear being put on inverted. There is a 1st gear side and a 2nd gear side. 3rd& 4th and 5th&6th do not matter which way they go on.

 

thank you. just did all this yesterday and there was no coolant loss. some said here or rl coolant comes out? whatever. pentosin yeah.. coolant nope. at least not the "easy" way lol

 

Bearing noise once damaged - not whining; a slight grinding noise most pronounced in 1st & 2nd gear.

I immediately recognised the noise as I've had it before.

 

Can you explain the pentosin part? Why would this come out?

 

Here is the bearing from the first time round.

Question...

To get to this bearing my first tech disassembled the whole gearbox.

Is this also required now for this "2nd bearing"? Or is this second bearing by the diff and is therefore no need to disassemble/assemble the whole gearbox again?

I presume the first bearing (which went bad) is on the photo at the bottom of the shaft? Which/where is this this 2nd one which is pressed onto the shaft?

 

Do you have the part number of these two bearings??

I m asking because I will open my gearbox this week for GT2RS gear conv and maybe I must change these bearings too!

 

Unfortunately not. Will have them mid February when car goes in.

 

Here are the two bearings that take the most abuse.

999.052.094.00
999.052.164.00 This one more so then the other.

These two bearings locate the shafts, the 999.052.094.00 is on the main shaft and the 999.052.164.00 sets the pinion depth on the pinion shaft.

 

Thank you Tim!!!

Now Mark must order these two bearings for me too :-)

 

Thanks Tim.

 

sorry, i was replacing the cluch slave and master.. which is why my trans was dropped the other day. so pentosin was the only fluid i had to deal with. not any coolant, so i didn't understand why anyone said there would be coolant loss