Rb26 Throttle Shaft Leak

[Scooby]

Discovered an air leak in the rear throttle body. Initially presented as high pitched squeal at idle that immediately goes when you crack the throttle. Doesn't appear to be gasket related and a fine shot of petrol at the shaft end makes it run rough.

Suspect the TBs got washed when the head was recoed, apparently that will remove whatever compound Nissan uses during assembly. Hi Octane recommend a Tomei paste (wasabe and moly?) that is applied to the shaft ends on the inside of the TB and according to them to the butterfly also (not sure how this would help unless it's just to the sides of the butterfly to assist in penetrating the shaft space). Of course instructions are in Jap.

Wondering if any one has used it and if so can please advise how it works and how it should be applied.

Thanks in advance

[GTRNUR]

Ive had that before on my R33 gtr. I pressure tested the intake system and found that the leak was only under vacuum, and oddly it would seal up under a positive manifold pressure and hold a positive pressure once disconnected from the air compressor.

I solved the problem by spraying the ends of the shafts with a little INOX a few times when it was idling. No disassembly required. A little of the lubricant will have been drawn in to wet the seal. This made the noise stop. It may have also made the seal swell a little too. That was over 3 years ago, and the seals are still holding. (I stil see and occasionally work on the car).

The ideal approach would be to replace the seals and re-furb the throttles, or swap them with some from another car. Its a lucky guess as to weather you get a good throttle though. Getting the seals is the next issue. They cant be sourced from anywhere.

[doo doo]

Having just dealt with this issue I can recommend this product-

http://www.xs-engineering.com/xsstore/pc/s...tle+shaft+seals

The website doesn't work properly when ordering (can't place an order) and you can't phone the place (in the states, you get a machine)) but if you email them through the store email you'll get a reply, took about 2 weeks delivered all up and around 130 AUD. You also get to take your plenum and throttle bodies off which is lots of fun. I also have 4 good condition second hand stock seals available if needed.

Sorry the pic is a bit useless

[Scooby]

Thanks guys,

GTRNUR sounds exactly like mine. doo-doo I saw them when googling a solution, know Nissan have nothing but I hoped a bearing place might. Did you try locally?

[doo doo]

Thanks guys,

GTRNUR sounds exactly like mine. doo-doo I saw them when googling a solution, know Nissan have nothing but I hoped a bearing place might. Did you try locally?

You betcha i tried- took the seals to a custom seal making place and every bearing shop with no luck. Rang EFI in vic but no luck- you can probably find a seal that's close but you'd need to modify stuff.... I put the plenum and throttle bodies on a pressure testing jig I'd set up and ran 30psi with the standard seals (2 popped out) and then the XS seals (no leaks) They do have a spring in the inner lip but it's still a twin lip for both vac and boost. the main issue i had with seal places was the minimum thickness they had off the shelf was 6mm and the stock seal is 3mm thick. i reckon the XS is worth it for the hassle it saves.

[Scooby]

I agree hope to get the ball rolling as soon as I hear from them.

[Scooby]

Update for those interested. The US place with the seals isn't communicating by email and the phone isn't working. Tomei paste turned out to be just moly.

Took oem seals out - those that didn't fall out once the nuts on the end of the shaft were removed. Seals were in pretty poor shape and well pushed out note they are 2.7mm thick so not much room to move anyway. Found some double lip seals OS 10173 that are similar to the oem ones but about 1mm smaller OD. They look like the ones the evo boys use to correct the issues they have with boost leaks.

Pulled out the oem bearing retainers and replaced them with some new ones to suit the new seals, but with a small retaining lip. All bottoned up again and it runs fine. Recommend anyone who has their tb's off look at doing this, just check out the state of the oem seals and how far they are pushed out particularly if you're running higher boost. I upped mine to only 18 psi and they got bent out of shape.