R33 gtst gearbox top barb

[zigrb30]

Hi all,

I am putting an r33 gtst gearbox into a VL and have noticed what looks like a vacuum barb on the box (on top in the middle).

Suspecting that it's a vacuum line but I'd like to double check, if someone could confirm the function of that would be great.

Cheers in advance.

[Duncan]

Do you have a picture? I assume it is a breather for gearbox oil as it expands, it should have a vacuum line run nice and high in the engine bay (R32 GTR has it on a top bellhousing bolt)

[GTSBoy]

  On 09/02/2025 at 11:45 PM, Duncan said:

I assume it is a breather for gearbox oil as it expands

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Absolutely this.

  On 09/02/2025 at 11:45 PM, Duncan said:

should have a vacuum line run nice and high in the engine bay

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Yes, except not vacuum hose. Something oil/fuel safe is a better idea.

[joshuaho96]

  On 09/02/2025 at 11:16 PM, zigrb30 said:

Hi all,

I am putting an r33 gtst gearbox into a VL and have noticed what looks like a vacuum barb on the box (on top in the middle).

Suspecting that it's a vacuum line but I'd like to double check, if someone could confirm the function of that would be great.

Cheers in advance.

Expand  

Breather for it. If it's anything like the GTRs it should run up to the top of a bellhousing bolt.

[zigrb30]

Cheers for the replies.

So i don't connect it to the manifold I just run the hose high up on the firewall?

[GTSBoy]

Oh, yes. If you connected it to the manifold your first drive would be very eventful. Very shit. Very interesting. Perhaps take a video if you feel the need to see.

Terminating the breather at the top of the bellhousing is normal/stock. Some gearbox lubes (hello Redline Shockproof) like to foam up a bit and require the breather to be extended up higher, so you don't get spots of smurf jizz staining the floor under your car. Mine is thus right up behind the head. Make sure you fit a u-bend at the top so it points back downward so that dirt and schmutz has a harder time getting into it.

[Dose Pipe Sutututu]

  On 10/02/2025 at 9:59 PM, zigrb30 said:

Cheers for the replies.

So i don't connect it to the manifold I just run the hose high up on the firewall?

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Please do not connect it to your manifold.

If you do, as GTS suggested please record the lot in 4K with good mics attached.

 

On the factory Skyline, there's a upside down pipe that allows it to breathe, looks like this 

 

[zigrb30]

😂 thanks guys.

The diagram i had did not have the breather on it at all.

Much appreciated.