Plastic or Bronze Throttle Bellcrank Bushings?

[frankc]

Hello,

Our host sells three types of replacement bushings for the throttle bellcrank on the transmission (914-423-211-00), and I'm trying to decide which to choose:

• OEM Plastic
• Bronze
• Oil Impregnated Bronze (Weltmeister)

In searching this topic, many folks tend to view the bronze option as a better alternative to the plastic, but I have seen some say that the factory chose plastic for a reason (not cost), but I'm not sure what that reason is.

I guess one concern I have with the bronze is if it is not lubricated well, that it will wear down the bushing and the shaft, where as the plastic would simply wear down the bushing.

I would like to add this to my order tomorrow, so any insights would be greatly appreciated.

Thanks

[timmy2]

I went with the weltmeister ones for the lubrication.
Good fit, no problems.

[gamin]

Weltmeister or bronz. Never plastic.

[BlueWing]

I am doing this same job and have one plastic and one bronze. i need to order a second bronze one. However the two I have are have too large of an outside diameter. Neither will fit into the bell crank tube but the ID seems ok.

Plastic 914-423-211-00/256
Bronze 914- 423-211-00/105


Any thoughts?

[mcaterino]

The bronze ones I got from our host were also slightly too large O.D., but a little sanding (jammed a pencil in the hole for easy holding and spinning) and with a vice was able to press them in without too much trouble.

They should last a while.

Mike

[porterdog]

If the shaft is steel it's very unlikely that the bronze would wear the steel shaft.

[Daves911L]

Use the white plastic, as per original. It produces the correct "feel" in the linkage. And yes, they do wear out faster. You'll probably have to buy a new set every 10 to 15 years. Same for pedal cluster and shift linkage bushings. While you are at it, there are small plastic sleeves inside the tunnel that guide the throttle rod. Quite a few of these have rotted to bits now. A very tedious job to replace! When all is done you will have smooth tight control linkages with no squeaks or rattles.

[Rot 911]

I'm with Dave on this. Go with the plastic. Works just fine, easy install, just replace every 10-15 years. Mine were still good when I replaced them with new plastic ones after 20 years.

[frankc]

Thanks for all the feedback. I think I'll just go ahead with the plastic bushings - the ones I removed lasted 35 years (albeit they crumbled upon removal), and they are not that difficult to replace. However my plan is to go with bronze for the pedal cluster bushings (next project).

Dave - thanks for the tip on replacing the throttle rod bushings in the tunnel. I have the tunnel all open right now to replace the fuel & brake lines, and add a hand throttle, so this is a perfect opportunity to replace these bushings as well (I already replaced the shift linkage bushings).

[ratpiper71T]

I believe and hope I don't misquote him, but I think it was Grady that said the plastic was used by the factory so that brake fluid if leaking from the MC would quickly damage the bushings and make aware the driver that there's a problem... I think.

[frankc]

Originally Posted by ratpiper71T

I believe and hope I don't misquote him, but I think it was Grady that said the plastic was used by the factory so that brake fluid if leaking from the MC would quickly damage the bushings and make aware the driver that there's a problem... I think.

I'm not sure if this was an actual objective of the factory, but yes - this is true for the pedal cluster bushings, especially for pre-77 cars without the brake booster since the MC is attached directly to the pedal cluster as opposed to being located in the trunk area on PB cars. Not so much for the throttle bushings being discussed here, methinks.

[ratpiper71T]

Oops, yeah reading comprehension mishap.

Quote de ratpiper71T

I believe and hope I don't misquote him, but I think it was Grady that said the plastic was used by the factory so that brake fluid if leaking from the MC would quickly damage the bushings and make aware the driver that there's a problem... I think.

I'm not sure if this was an actual objective of the factory, but yes - this is true for the pedal cluster bushings, especially for pre-77 cars without the brake booster since the MC is attached directly to the pedal cluster as opposed to being located in the trunk area on PB cars. Not so much for the throttle bushings being discussed here, methinks.

[Vintage56]

I replaced the two plastic bushings today on my '73 911 bell crank. The original plastic bushings finally crumbled. I used 2 new plastic bushings purchased from our host. The install is simple and straight-forward. However, for those attempting to do this on a fully-assembled car with the left trailing arm of the suspension in place, an additional step is necessary.

The issue I ran into was once the cotter pin and outer washer are removed and you disconnect the ball cup from the link from the gas pedal, the bell crank itself will not be able to slide out all of the way to the left to clear the rod that the bell crank slips onto. At least this was my experience with my 911. The only way to remove the bell crank itself beyond jacking up the car, is to remove the rod that is bolted into the engine crank case as described above in prior posts. I just wanted to clarify the procedure for others attempting to do this simple job since the prior posts may have implied this to be necessary, but wasn't clear to me anyway until I went to actually do the job.

The rod itself requires an 8mm open wrench to remove it, but you have to lubricate the the rod where it meets the engine and let is sit for a time before attempting to unbolt it. The entire rod, inner washer, and bell crank need to be removed together to clear the trailing arm. Then you can separate the bell crank from the link to the MFI above, clean up the bell crank, replace the 2 bushings, lube it, and reinstall the rod, inner washer, and bell crank together as one unit. Lastly, I installed the outer washer and cotter pin. Also, while it was apart, I removed the ball socket from the link from the gas pedal, cleaned it up on the wire-wheel, removed 45 years of dirt and gunk, and reattached the ball socket to the bell crank.

It's a straight forward job as noted. Enjoy!

[ADDvanced]

Just adding to this... I purchased a set of new plastic ones from our host over a year ago for my build, took them out of the package and both were cracked/crumbling already. I know people say they'll last another 10-15 years but if they've been sitting on a shelf for 15 years already, yeah. I ordered some bronze ones.

[Jeff Alton]

We use the white plastic OE style ones. Keep them in stock. Been using them for 10 years, no issues.... But, that said, use what fits your comfort level.

Cheers

[pampadori]

Got 5 years out of the plastic ones but then when engine would get good and hot (say, after an hour or so driving) the throttle would not return to fully closed. It would cause my idle to act wonky and sometimes my off throttle fuel cut wouldnt engage. Essentially the tps was reading just a hair too high for idle and fuel cut to work. Super annoying believe it or not. In the end the issue was the plastic bushings. Swapped in some bronze and never had the issues again.

[Trackrash]

If your plastic bushing fails it could cause your throttle to stick to the floor. AHIK.

[RobFrost]

Just thought I'd add that you DON'T need to remove the stud from the gearbox. You only need to do that if you press the bushings into the cylinder first. If you press the bushings in, in situ, particularly the 2nd one to go on, you can JUST get the assembly together without unscrewing the shaft.

Sent from my SM-G988B using Tapatalk

[Tyson Schmidt]

If you use the plastic, lubricate them with silicone grease.

This goes for the shifter bushings too.
Petroleum products break down plastic over time.

[ADDvanced]

Not sure people saw my post, but PELICAN IS SELLING OLD CRUMBLING BUSHINGS.... Go bronze.