BBK throttle body leaking shaft seals

[knever3]

I have been chasing an erratic idle for YEARS.  I finally bought a smoke machine and after 5 minutes or so I saw smoke coming out of both sides of the shaft.  After looking at BBK's website they don't sell ANY repair parts or provide rebuild service.  What a crock, they will offer to sell you another!  Great business model.

[Eagle_SX4]

I may be wrong but I don't think there are any actual seals on the throttle shaft. I think the seal relies on the sealed bearings. That is at least how the Renix throttle bodies are. 

 

You could test to see if that is a real issue by spraying starting fluid at both sides and seeing if the idle increases.

[AZJeff]

If you have erratic idle, I assume the throttle plate shaft is loose in the bores of the throttle body housing.   This causes the throttle plates to have varying degrees of clearance around the Venturi each time the throttle plates ope/close.   I had this happen on Weber carb on a 2.0L Ford engine back in the 1970’s.

 

There are only two ways to fix this:  get a new throttle body assy or get a machine ship to bore out and install brass bushings into the wallowed out holes in the existing throttle body.

 

neither way is terribly cheap, unfortunately 🥴

[knever3]

Correct, I think they used leaky sealed bearings.  I will post the result.  I wish you can post a video without having to post it on youtube 

[knever3]

 

[Eagle_SX4]

I don't hear any surging and the stumble seems to not be consistent with the spraying of fluid. Must be a small enough leak that the engine doesn't seem to care about it.

 

What idle air control valve do you have, Renix or H.O.?

 

When I went to the 98+ horseshoe manifold and throttle body I kept the Renix idle air control valve. However after watching my REM it is constantly sitting at fully closed to keep the idle down. I am going to swap out to a H.O. IAC valve and see if that helps keep it from being fully closed all the time. This might be your issue as well.

[knever3]

I think I have a Rexix one, I have an updated H.O. style in the box.  That is the next step.

[75sv1]

I've resealed a few HO TBs. I think there is some instructions from someone  else , yeah somewhere. There are two O-rings on both sides. Sometimes the shaft is fretted though. I would take out the o-rings, clean out the bearings and regrease them. Then put in new orings. The originals look to be Teflon. I forget what I used. It was not your regular black Buna-N. I think a fluorocarbon. 

[AZJeff]

43 minutes ago, 75sv1 said:

I've resealed a few HO TBs. I think there is some instructions from someone  else , yeah somewhere. There are two O-rings on both sides. Sometimes the shaft is fretted though. I would take out the o-rings, clean out the bearings and regrease them. Then put in new orings. The originals look to be Teflon. I forget what I used. It was not your regular black Buna-N. I think a fluorocarbon. 

That’s more sophisticated than the damned Weber I had.  Just a straight (plated) steel shaft thru an aluminum die cast carb housing.

[75sv1]

I think I used Nitrile orings. Nitrile Butadiene has a higher temp rating. 

[Gojira94]

Jeff at http://strokedjeep.com/ might be able to redo throttle shaft bushings/ bearings/ seals/ whatever on your BBK unit. If anyone can do it, he can.