I'm right in the middle of my BBD rebuild. Fun isn't it? I'd better be having fun.
As to the throttle body shaft, I've got no play in the non-spring/screw side, but slight play in the spring/resin-plastic-spacer side, but no leak that was obvious ( I don't think anything could have got past all that grease and dirt). The resin-plastic spacer looks "hammered" on the side next to the throttle body, even though it appears that the shaft can't move back and forth. There is a significant space between the resin-plastic spacer and the throttle body, and at the other end between the throttle body and the control tab that fits on first. I think I have a fix for leaking throttle bodies. Remember, that's I THINK!
Teflon washers on the shaft.
The Teflon is soft enough that it should wear to fit perfectly and deform/intent/etc. to fill voids. From memory, it'll take a .6mm washer on the tab side and 1.5mm to 2mm washer at the spring side (and with an outside diameter under that of the resin-plastic spacer to ensure it doesn't get torn up by the spring.
I'm assuming that by either polishing the throttle-body/washer contact points or by using double washers or possibly triple washers (with a non-Teflon washer in the middle - dis-similar plastic-to-plastic contact to ensure no plastic-to-plastic welding), that I can completely fill the space and count on the low static and dynamic friction of Teflon to have no practical affect on the movement forces of the throttle.
I can't think of why this wouldn't work. Am I missing something?
Most commercial plastic supply shops have Teflon sheets. A leather hole punch, wordworking- forstner (not toothed) or brad-point drill bits should work fine to make washers from the Teflon. I have some Teflon kicking around. I'll have to check sizes.
I'm going to try and I'll post the results. If this works, it'll give us a lot more usable throttle bodies.
Actually, for an extremely worn throttle body, why not drill it out oversize and have a Teflon rod machined into a flat capped plug that is drilled out for the shaft? And rather than custom machine something, the plastic supply shops may even have an existing Teflon part for something that can be drilled out to take the shaft. If there was a lot of force involved, Delrin AF would be a better plastic to use for this replacement bushing, but you'd still want a Teflon washer for a seal, or would you? Interesting. Delrin AF is a hard resin plastic (Delrin) with either powder (particle) or oriented strands of Teflon (the AF, or anti-friction part). It is very wear resistant against steel (the harder the better, and lower friction) and it's both chemically and particle contaminant resistant. It's dynamic friction is greater than it's static friction so throttle action would be very smooth as well, with no sudden break-force. Too bad all my Delrin AF rod is too large for this.
Canoe
Topic: Carter BBD Rebuild (Read 14525 times)