gsxtasy
20+ Year Contributor
- 859
- 19
- Oct 17, 2002
-
Lincoln,
Nebraska
Alright, so after finally getting fed up with my leaking s90 TPS side throttle shaft and temperamental idle, I decided to tear into it. Previously I was under the impression that there were no seals at all in the s90 and only ball bearings on the shaft.
There is a seal!
The seal is recessed behind the bearing on the TPS side and there is no seal on the throttle cable side. The first thing that I noticed was that the seal is installed backwards for sealing boost into the engine. I'm guessing yours is too.
I have removed the seal and it says NAK VC 10 16 4 on the back side of it, which is the brand and size of the seal, 10mm ID x 16mm OD x 4mm W.
I ended up sourcing some double lip seals with metal cases of the correct size from: http://mechaniseals.com/10x16x4tm-t...m-id-x-16-mm-od-x-4-mm-wide-nitrile-material/
However, they have a $25 minimum order and $7 flat shipping so I just ordered 10 of them. PM me if you need one.
Disclaimer: I am not a seal expert, so there may be better options out there.
That being said, I have installed the seal the correct way with the addition of some dielectric grease and reassembled the S90. I used a socket with the correct diameter and tapped it into place. It is a tight fit.
To ensure I have the best idle possible, I then coated the back of the throttle plate with dry moly lube to help seal any possible seepage around the throttle plate itself. I also then made a decent gasket from a thick cork/rubber material, since the paper one it comes with is worthless and I didn't want to RTV it on, again, if I didn't have to.
I just went and boost leak tested it again and the shaft seal holds fine up to 30psi(highest I can get my little compressor to push out).
Side note: the throttle plate screws are M4x.7x8mm. They stick out some on the back side and a M4x.7x6mm would probably fit fine.
Hopefully that helps somebody out there as I was struggling to find information.
There is a seal!
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The seal is recessed behind the bearing on the TPS side and there is no seal on the throttle cable side. The first thing that I noticed was that the seal is installed backwards for sealing boost into the engine. I'm guessing yours is too.
I have removed the seal and it says NAK VC 10 16 4 on the back side of it, which is the brand and size of the seal, 10mm ID x 16mm OD x 4mm W.
I ended up sourcing some double lip seals with metal cases of the correct size from: http://mechaniseals.com/10x16x4tm-t...m-id-x-16-mm-od-x-4-mm-wide-nitrile-material/
However, they have a $25 minimum order and $7 flat shipping so I just ordered 10 of them. PM me if you need one.
Disclaimer: I am not a seal expert, so there may be better options out there.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
That being said, I have installed the seal the correct way with the addition of some dielectric grease and reassembled the S90. I used a socket with the correct diameter and tapped it into place. It is a tight fit.
You must be logged in to view this image or video.
To ensure I have the best idle possible, I then coated the back of the throttle plate with dry moly lube to help seal any possible seepage around the throttle plate itself. I also then made a decent gasket from a thick cork/rubber material, since the paper one it comes with is worthless and I didn't want to RTV it on, again, if I didn't have to.
You must be logged in to view this image or video.
You must be logged in to view this image or video.
I just went and boost leak tested it again and the shaft seal holds fine up to 30psi(highest I can get my little compressor to push out).
Side note: the throttle plate screws are M4x.7x8mm. They stick out some on the back side and a M4x.7x6mm would probably fit fine.
Hopefully that helps somebody out there as I was struggling to find information.