Well I'm not sure about yours , but here's what's in mine...

Yes, and I'll be making a few of those hard to find leaky gaskets....
























Ta daa



Yup, those gears are sharp...





I took the majority off it apart and nothing obvious jumps at me as to tracking down the infamous whine...I'll go over everything with a fine tooth comb tomorrow and over the weekend.

Below is a pic I'll be busting out from now on anytime someone asks why the front differential only handles 40% of the power max or so. If you look at the below pic, below is the gear-set that transfers the power from the TIP output shaft and splits it onto the Rear Differential and the Front Differential...Well, the top gear is for the .....you guessed it those fat tires in the "Rear" and the bottom is for the flimsy viscous linked poor excuse for a 4x4 wanting to offroad "Front"...







Below is the receiving gear that powers the front differential.



Enough for today. I'll probably post more tomorrow.

 

awesome and i must say that you are very brave, good job!

 

Now this is what I need. Keep them coming please!

BTW would you please upload some photos of the jack stand you have there as well?

I like the finger shot...ouch!

 

I'm guessing that single brace (orange one) is holding the engine up once you removed the gearbox frame? (The piece that holds the front of the gearbox to the chassis, scuse my non-technical terms!)

 

Great job, I wish I can work on my own car.

 

Bl@@dy Hell, the difference in the front and rear gear tooth sizes. You would't want to uprate the front VC too much if the drive train is like that!!
Well done by the way, keep it comming. Well worth a Rep point

ps just thought you should get a Job with Haynes and do a " Haynes 996tt repair Manual" LOL

Frank.

 

I did this same job on mine. If you need any help with it let me know. Keep in mind gasket thickness, as the gears use cone type bearings and if you use thicker gasket stock you will end up with play in the bearing and trash the gearbox. I made both gaskets and replaced the "o" rings on the tube that crosses over from the tip pan.

 

Hi Mikey,
Why did you have to do this to yours?? Is there a recurring problem with the Tip.
I'm very interested because up to recently, parts were not available for the Tip.
where did you source your parts.
Also the 996tt Workshop Manual does not cover repairs to the Tip box. Is there a W/shop Man' for the Tip with maybe exploded views of the internals.

Your answer will be greatly appreciated.
Frank

 

there is a leak at a gasket on the tq and porsche didn't produce that seal for sale, because of this they are telling the clients that they should change the gearbox

 

I use on mine the "gel" from Victor Reinz, the producer of the gaskets/seals, two years ago and until now (knock on wood) there are no problems!

 

The tip sometimes leaks at the mating gaskets(the two in the picture). You will know it is leaking because you will find the pan wet and the plastic panels on the bottom of car will be dripping a reddish color fluid. The gaskets are not available and have to be fabricated. Porches answer was to replace the entire transmission at a cost of $8k plus labor. The parts manual has a blow out of the parts contained. The only thing really critical during the job is that the counter(center) gear goes back correctly. It can be installed backwards. Also when sourcing the fluid it is only available from Porsche in a barrel. I got liter bottles from my local Benz dealer.(its a benz trans)

 

Thanks Mikey,
I recon looking under mine I might be doing the same some time soon.
How about exploded views of the internals of the box or exploded parts diagrams. Do they exist.
Good tip about the oil from Benz..
Cheers
Frank.

 

Hey Mikey,

Thanks for chiming in as I have a ton of questions. Because of the limited info available on this Box it is greatly appreciated.

The only exploited diagram I found is off the front of the box giving a few part numbers but really limited. I also found a sheet in the factory manual with some torque specs for the cases but not really anything for the inside of the trans. If you could advise as to what values you used to torque down the bolts securing the gears.

The gaskets I have appear to be in fairly good shape (not torn) and I was going to use a silicon gasket spray that my buddy recomended that supposely reconditions gaskets and makes them better than new without adding significant thickness.

Also, was the leak the only reason why you took yours apart? Mine had very little seepage, but the trans would whine when not under load (just when I lift off). So far I traced it down to the output shaft for the front driveshaft. Upon closer inspection I found a hairline crack in the pilot (roller) bearing cage and excessive play in the main bearing. I'm already having a hard time sourcing that one but have my fingers crossed.


Thanks,

Adam

 

First thing to do is to remove the airfilter assembly as things could get ugly if you dont

Than I removed the front transmission mount, but that made the trans drop just slightly so I decided to remove the braces holding the suspension cradle and the cross brace under the engine. Well that made it drop another inch but the axle shafts were held up on the suspension members. Than, I loosened up the engine mount nuts holding up the engine towards the rear of the car. I basically backed them off a few turns to give it some slack but enough to where they still hold it up. Than I removed the 6 nuts holding up the suspension members which made them drop a few inches. (they're still held up by the shocks and axles). The Orange brace is a hydraulic jack. Normally it's used to repair bodywork and for frame straightening, but the modular design and adjustable length makes it perfect for stuff like that.

I didn't want to do a step by step DIY on this as it's definatelly not the easiest project and I wouldn't want anyone thinking it's easier than it actually is and than end up with a bucket full of parts, but it appears like I'm not the only one that's tackling it, so If anyone wants to go for it and they come across this thread I'm sure we can all lend a helping hand to guide them through it.

 

W00t!!! I found the source of the whine. And it wasn't the "pilot" bearing I was suspecting. Upon closer inspection it turns out that that bearing has a tiny steel cage that looks cracked but it's formed right there. Pictures soon.