am

Here it is. In this thread I'll write how I did the disassembly and reassembly of my manual tranny for pinion bearing change. I began with Nick Hends DIY who did the same but for a C2 which is different from a Carrera 4 transmission. Unlike Nick I did the complete disassembly myself
You can find Nick's thread here : https://rennlist.com/forums/996-foru...ement-diy.html

I took plenty of photos that I'll post and I'll write the dimensions of the bearings I changed. I got some tricks that I will explain too.
At the time of writing the beginning of this thread the complete tear down of the secondary shaft was done and I was waiting for new bearings.
Please keep in mind that some sentences may sound odd or strange it's because I'm french native. I'll do my best.
Also I don't necessairly recommend what I did to anybody. I know that the method I used to separate the 2 shafts is discutable but I took the decision to do that in MY transmission. I'll write this thread a bit at a time since this requires a certain amount of time that I don't necessarly have. I hope this will help others at least as much as I got help on forums in the past.

MiataR

Awesome... really looking forward to seeing this.

am

First nose cone removal.
I removed the 12 bolts that attached the nose cone to the housing but I was'nt able to remove the cone. When I was moving the biggest shifter lever the cone seemed to move out a bit but I could'nt lift it more than 3/4th of an inch.
Then I removed the bolt that we see in the middle of next photo.
It has liberated the cone but I've put the assembly that the bolt held at it's place in the cone for the time of reassembling. Be careful for the threaded hole in the shaft vs the bolt

am

To be continued

808Bill

Thank you for writing this up.

am

Here is how I disassembled the fork Shifts.
I gave them numbers from 1 to 5, #1 beeing the nearest to the magnetic washer.
First I punched out pin #1 on shaft #1. Then I had to pull the shaft up while holding the fork and lock plate. A good idea is to clean the shaft and use nitrile gloves cause its hard to handle the shaft when it's oily. It came up a little bit at a time until free.
Second I punched out pin #2 to remove shaft #2. The pin went out but not completely. I punched it as far as possible and between 2 teeth of the reverse gear. After that I have been able to remove shaft #2 like the previous shaft holding the fork and the lock plate at the bottom.
Third step, I punched out pin #3 on fork shaft #4, I punched out pin #4 and pin #5 on fork shaft #5 and I had no choice to remove them together. Take care to check how the ''lever'' that pin #4 holds goes to be sure to put it back the same way when reassembling.
Forth I removed shaft #3 easily but like Nick Hends mentioned in his DIY take care not to lose the 4 little guides or rollers at the bottom of the fork shaft #3
That's it for the fork shafts removal.

am

When all fork shafts were removed I took off the Torx bolts holding the steel plate against the casing. For this part my procedure was the same than Nick but I heated the case with a heatgun not a torch. I never heat aluminum with a torch. Then I pried with pry bars protecting the aluminum casing.
The shafts came out slowly and one of the half of outside race of main shaft bearing stayed in the tranny casing. (see photo)

am

OK Here's the interesting part. It's for this step that I've been a naughty boy. I did'nt want to work with a puller to disassemble the secondary shaft. I hate pullers. They bent, they slip they have a pretty small holding surface at the tip of the gear teeth. I prefered to press everything out. It would have been pretty hard to press out the gears with both shafts attached together cause they weight aroung 70 lbs. I checked with Nick's DIY and I don't believe that I would have been able to separate the shafts after the removal of reverse, first, second gear and cutting the main shaft bearing. So I cut the bearing.

am

Then after checking the uses of the steel plate, 1- reinforcing the aluminum casing between the 2 shafts 2- holding the bearings in place in the aluminum casing 3- the shape of it around the main shaft that helps splashing oïl for the bearing.
I decided to cut a little piece of the steel plate from each side around the main shaft so I could remove and put it back freely. I used an air tool, a cutter with 2 inch disc and finished with a dremel.
I don't think I did anything taht bad or dangerous for the tranny and remember I took the risk for myself.
If I weakened the plate it's not significant. It will still hold the bearings strongly and the splash oïl function won't be much affected.
Now i can work my way on the press and disassemble everything from the secondary shafts.
To come...

Schnell Gelb

Very creative ! I hope it works well !

am

Time to press!
The first steps are the same than in Nick Hend's DIY.
I removed the C clip from the tip of the secondary shaft and the spacers. I took great care to classify every action and put parts in order for reassembly. Like I wrote earlier I did'nt use a puller but a press. I did'nt need the special tool to put in the shaft cause the auxiliary shaft of the Carrera 4 is not hollow. I just made a special tool to keep the tip of the shaft at the right place under the piston of the press. It made my work very safe.

I began like Nick by removing everything before the first gear. I went slowly and when I saw the needle bearing appear right Under that assembly I've put a tie-rap around not to loose anything just in case.
Then I presse everything before the second gear and did the same thing with needle bearing right Under as soon as it appeared. I did'nt have the 3 ball with springs like Nick had on his C2.
Those 2 steps came out easily with not much pressure (Under 2 tons).
On the 3rd photo you can see the tool I've made on top of the shaft.

am

The next pressing step was the most impressive. The removal of these 2 gears required 25 tons of pressure. Note that for the previous steps I heated the parts with a heat gun and for this step and the next one with a propane torch. I did'nt had the choice to remove them at the same time.

Then the last one required much less pressure (around 10 tons). I pressed pushing on the steel plate.
Then I pressed out THE bearing who was very easy to get out. Last photos show all the parts classified and the pinion bearing. I opened only one side and saw at least one problems immediatly.

Voilà !!
I hope it will help. Next i'll post the part numbers I used and dimensions of the bearings just for everybody to find everything at one place.
I don't think these bearings can be substituted with anything though.
Because there was a mistake in my order about the pinion bearing I'm not ready to press everything back yet. I'll do that soon. I'll take many photos of the reassembly and if ever there is something more interesting than : ''Use the reverse order to reassemble'' I'll put photos here.
Cheers

am

Here are the bearings I will change in this job.
On the left is the Pinion bearing with Porsche part number and on the right is the Main shaft bearing that we have to cut to separate the shafts with it's part number.
The next photo shows the pinion bearing with Porsche part number and the number engraved on the bearing. It's the same for the last photo but it's for the main or primary shaft.

The dimensions of the pininion bearing are : 48mm ID, 93mm OD and 37mm thickness (34.5mm to the knotch) sorry we don't see the what I called a knotch. I could post a better photo later.
The dimensions of the main shaft bearing are : 35mm ID, 72mm OD and 34mm thick.
Both are double ball bearings separate in half.

Schnell Gelb

The '808'- 996 302 808 00 bearing is here:https://www.123bearing.com/bearing-801641E-***.php 48x93x37mm
The '807'- 996 302 807 00 bearing has already been searched and is difficult to find.I tried "Bearing 8055519383" and got nothing.be careful just searching by size 35x72x34mm -you may be mislead by items like this:http://www.ebay.com/itm/NTN-BEARING-...-/221191814266
As the Op = am wrote :"Both are double ball bearings separate in half. " If you look at his photos, the inner race is a single piece. The outer race is split !
Here is a link to a good photo & a bad price:
https://www.carpartsdiscount.com/man...ml?3593=525997
Please confirm with your own research before buying! And please correct this post if it is incorrect !

am

Here is a photo of my pinion bearing installed where we can see the ''notch'' I was talking about previously.
I just finished the first part of reassembly and I have a couple of good infos.
I decided to leave the seals of the pinion bearing in place cause I said to myself '' the original Porsche bearing with magic grease had last 100 000 miles so if I leave it like that I will be sure to drive it a very long time before worrying''
Wrong, I opened the split pinion bearing and saw that there was only a bit of yellowish grease Inside. The bearing was in place but I have been able to remove both seals (first and second photo).
Also I attached the steel plate to the steel bar I used to sit the shaft on. It assured the steel plate and the shim to stay in place while pressing the first gear to go back on (third photo).
I'm halfway done, I've put back separately the gears that needed 25 tons to be remove together. The worst has needed around 15 tons to go back in place.
Here where I stopped tonight (fourth photo)
Last photo shows the 1 inch X 2 inch steel bar I used to sit the shaft. It bent a little bit