How to Overhaul R33 GTR Propshaft

[Fastlane]

Overhaul of the Propellershaft on the R33GTR

As the Propellershaft  on the R32 / R34 are similar, it should be the same there.

On mine, the rubber in the center bearing was completely defective and the constant velocity joint on the differential was jamming and was difficult to move, although there was hardly any wear visible.

On the joint in the middle, only minimal wear on the surface was visible and it was easy to move evenly, so I didn't replace it.

The universal joint was still very good and hardly worn in.

Here is the matching replacement joint

Porsche part No.: 91133203001

Length [mm]: 32 mm

Number of holes: 6

Number of holes: 6

Bore circle diameter [mm]: 94 mm

Internal toothing diff. side connecting shaft: 28

Outer diameter [mm]: 108 mm

Bore diameter [mm]: 10.9 mm

The joint is a perfect replacement, the only difference is that the diameter of the cover is too large. If you cut off the edge, it fits very well. The only thing that is a little more difficult is the assembly. You can also just leave the cover off, it's actually just to prevent dirt from getting in during transport.

 

Here are some tips for assembly:

Mark each individual part how they originally fit together! It's best to take additional photos. If it can't be put back together the same way, it needs to be rebalanced. If you replace the middle joint, the toothing needs to be aligned so that it fits exactly with the original holes for the screws. It doesn't matter with the joint on the differential, as the shaft is not balanced with the differential.

In my case, the joint came off the gearing easily, but the new one was much harder to put back on. It's best to mark the joint, disassemble it and heat up the inner part. Then it's easier to assemble.

Important!!!!! The inner part and the outer part look like a star with large and small points. There is always a large and a small one facing each other. If you put them together incorrectly, the joint will block.

The screws on the differential and in the middle have different lengths.

If you replace the rubber center bearing, note that this is not symmetrical. Some have an arrow in the rubber that points backwards, just like the rubber dots on the edge. Take photos beforehand!

It's best to cut off the old rubber all around, clamp the bearing firmly in a vice and hit it firmly with a hammer. Put wood or copper underneath to protect the thread. The bearing is not very tight. You can't use a puller because there is a metal collar on the shaft behind the bearing.

Handle the universal joint on the gearbox with care, do not hit it. The needle bearing is sensitive.

If the joint cannot be detached from the differential, do not bend it and use force to remove it from the flange, as this could damage the joint.

It is best to build a puller and press against the joint from behind. The Thread is M10x1,25

 

The Torque Specs

 

If you have still any vibration you can choose another position of the Propshaft with the Gearbox and the differantial.

I hope this is helpfull to anybody!

 

regards

Kai

[fletch rb30]

Great info.

Dead right about the centre bearing being backwards. I put mine on wrong thinking the F in the rubber molding meant 'front' but it actually means back...

You can also replace the boot. I bought a GKN high speed boot like this:

https://en.oreca-store.com/gkn-cv-joint-boot-for-cv-joint-a-107-mm.html

or

https://www.race-parts.com/gkn-108mm-od-size-15-cv-tripode-joint-fast-boot

I found my cv's were in good condition and i just washed them out and re-greased them with new boots.