- GD2B-R Build tips -

An overiew about the GD2B-R parts. The included OR05V and OR13V o-rings can be always detected by the slightly brown shade.

First i check how smooth the PIN02 slides into the ST31-1 shaft. This can be sometimes a bit tight during small burr's from production. I use an small round diamond file and just turn it one time slightly inside to hole.

The next part where many guys struggle is the correct installation of the OR05V inside the case.
There is one easy method for this, like i show on this picture. Place the OR05V inside the AT123B/AT124B diff housing without any grease or lube. Now use an 5,5mm nut driver and press the oring fully into his position.
Yes, sometimes its hard to, but trust me, it will fit and stay there.

After you pressed the OR05V into his position, you should install the B85 bearing. Please do not use any tool for pressing. I recommend to do this with your fingers only. Press it until its same levle as the housing. In case the bearing sticks out 1-2/10 then the oring isn't in correct place!
The bearing need to be fully inside before you move on, otherwise you can't assemble the ST23X outdrives later.

Apply some silicon oil into the B85 bearing and onto OR05V at this stage to allow a smooth installation of ST31-1 part in next step.

Push the ST31-1 with WA03 washer during the housing into its position. Make sure WA03 is centered and in correct position on ST31-1 shaft!

I always use pliers to pull and turn the shaft a view times after installation to maker sure it sit correctly and moves smoothly.

Make sure to give the silicone oil some time to let the airbubbles move up. Alternative you can even use an vacuum pump for this.

Another useful tip is the "lighter trick".
After full screwing of the diff, let one side of the shaft still open and don't close it via P46R.
Use a lighter to heat up the diff case (turn it several times). Don't heat it up to much, otherwise you can destroy or melt the o-rings!

You will note some more air bubbles coming out and also the to much filled oil will bleed out. With this method you are able to get the 100% correct amount of oil needed in your diff.
Clean the shaft, put in P46R and install B106RS and ST23X to finish your perfect build GD2B-R diff.


M. Machler