Throttle Body shaft seal

[redrockergsx]

I have looked every where and I have found some shops that have replacements for 91 Throttle body seals. I also have read ever forum on here about replacing the seals but they were for a 91 and newer throttle bodies. I was wondering if any one has information on the 90 TB, since the shaft seal are different can the O-ring fix still work just with 2 different sizes. If not I will just have to make a harness for the new Throttle Bodies. Thanks

 

[allwheelTSI]

It really depends, are yours definitely leaking? Honestly I rarely see them leak, even in 150k mile plus cars.

To answer your question though, you'd probably be best off to contact a parts supplier for the manufacturer of the throttle body itself. Now if I wasn't so foggy tonight I would be able to tell you no problem, but I've been out of the DSM game for quite a few years and I just can't remember 100%. Any way though, I'm pretty sure its Mikuni, if not, its gotta be Keihin. You shouldn't have TOO much trouble finding a supplier for them that can order what you need.

Something else you may want to consider, the screws holding the throttle plate in are staked on the back side. Basically means they spread the end of the fastener out so if it loosens it can't come out and get sucked down an intake port. Makes it really difficult to remove without rounding out the phillips sometimes. Now some of them will come right out for you, no problem, the ones that won't, will have you pulling hair out. Easiest method is to just get the tightest fitting bit you can and a T handle driver/ratchet so you can really bare down on it and get some torque to it. Some people will take a dremel and try to knock off the fat part of the threads so it'll come out easier.

Other method is to have a mill/drill press and chock it up(TB) in an angle vice, so you can measure and set accordingly for the angle of the throttle plate, then you can drill them out by going straight through the middle of the screw head using a drill bit just slightly smaller than the screw threads. Honestly, when they won't back out and/or round it. This is the correct, and most efficient way of doing it without damaging the throttle plate threads. Then afterwards you can use new screws and just use some green loctite to secure them. I also recommend the new screws and loctite whenever you're taking the throttle plate out the first time, regardless of the method used for dis assembly.

EDIT: btw, I definitely wouldn't bother with the o ring 'hack fix'. the bore in which that shaft sits is a smooth bore with no kind of race for an o-ring, the seals are obviously specifically designed for this use. and if all else fails on parts location, these guys might be able to help: http://www.throttlebodys.com/DSMTBs.htm

 

[9!'clipseDOHC]

It really depends, are yours definitely leaking? Honestly I rarely see them leak, even in 150k mile plus cars.

Are you specifically referring to the '90 shaft seals or the shaft seals in general? I know leaking shafts seal in general, not specifically the '90, are very, very common.

To the OP, I have replaced my '91 TB seals (because they wouldn't hold any manner of boost) but I have no direct experience with a '90 TB. However, I did a little searching for you and this is what I found:

Just to add, the 1990 Throttle Body uses the Chicago Rawhide CR 3930 seal on the spring-side and the smaller CR 3030 seal on the TPS side.

Full specs:
3030 CR 8x12x3 HM4 R
3930 CR 10x14x3 HM4 R

Also note that the 1990 inner TB gasket is different from all other model years

Check out this thread for more info: http://www.dsmtuners.com/forums/bolt-tech/153753-90-tb-shaft-seals.html

 

[SBstar]

http://www.dsmtuners.com/forums/art...3135-1990-throttle-body-seal-replacement.html

That may help a little. The o-ring may work, you would have to locate the correct size, imho the seals are going to be a better bet and will last longer. And yes this is a very common leak spot!

 

[LiquidX]

I'm personally doubled up on o rings on my NT TB with out leaks up to 40psi on a boost leak test.

 

[twicks69]

I also keep these seals in stock if you need any:
3030 CR 8x12x3 HM4 R
3930 CR 10x14x3 HM4 R

For the 1990, you would use one #3030, and one #3930. For the 1991-1999, you would use two #3930 seals.

 

[allwheelTSI]

I suppose I'm just lucky in that aspect then.. Out of my 4 turbo 1g's I've yet to have one with leaky TB seals. I've run into every other kind of boost leak you can think of though. That's why I figured it was less common for those to go. Who knows.

 

[redrockergsx]

Thank a lot guys I rebuilt it today and it is a #7 o-ring and #6 o-ring. I put it back together and will do the test today, will back to you guys if it work. Again thank to you guys.

 

[LiquidX]

You did lubricate the o rings up really well right?

 

[milby43]

I hope it doesnt rip the seals apart again, if he didnt lubricate.

 

[redrockergsx]

no, I did really good thanks guys