Throttle/accelerator linkage assembly replacement

[Tommy Z]

Some of you may know that I recently acquired my dream car. A 79 SC with 123k on the clock. I found a knowledgeable independent Porsche tech here in the Fort Myers FL area who was kind enough to give my car a look see and help me identify what projects I should start looking at and which ones might not get me in over my head with my extremely limited wrenching experience. Cisco Bogannam of Bogannam European Automotive spent about an hour and a half with me just taking the car for a drive and poking around. He pointed out my worn throttle/accelerator linkage including the bushings that are attached to the bell housing. As it turns out I have only been about 2/3 of the way to wide open throttle at best when I floor the gas so good news, there is a lot more power to be had than I realized. I have been doing some research and found little info on what this procedure entails. Does anyone have a link to this repair including bushings etc.? I am a newbie and any help would be greatly appreciated. Here a photo of my new to me SC cause everyone likes a post with photos! Thanks!

[Walt Fricke]

1) Buy the 101 Projects for your 911 here from our host. It describes how to jack up your car, as a starter.
2) Buy a set of jack stands
3) Buy a lollipop - it it a round plate on a square steel rod and inserts into the jack point holders on either side of the car.
4) Buy a decent floor jack - 2 tons.
5) Download from the Porsche North America website the parts catalog for your car. However, you can probably find the parts diagrams you need in the 911 parts section on line at Pelican's website.
6) Order, probably from Pelican, the bushings for the throttle bell crank located on the left side of your transmission.

Replacing the two bushings on this part is not difficult, and I doubt anyone has described how to do it - 101 Projects doesn't, at least not directly.

A cotter pin holds the crank on a shaft which is screwed into the transmission. You should be able to disconnect the small ball joint which holds the rod coming from the accellerator. Not sure if you can slide the crank off at that point, because of the way the rod heading to the engine attaches, but you can try. If it works you can take the bell crank off and put it on your work bench and figure out a way to drive the old bushings (likely easy and just parts of bushings) out, and put the new ones in and put things back together.

If not, you must either a) unscrew the rod, or b) disconnect the rod at a bellcrank on the front (car direction) left side of the engine. That can be tricky as lots of stuff is in the way of your hands, but can be done. The pivot rod is screwed into the transmission case, but I can't quite remember what tool you need to turn it out and back in. It typically is never removed unless it breaks or gets super rusty.

The bushings on the bell crank on the engine can wear out. In addition, the bushings for the bell crank up front on the pedal cluster can fail. 101 Projects describes doing this in its transmission section under pedal cluster rebuilding. That task is a sort of rite of passage for DIY 911 owners.

Those are the main points where wear can introduce slop and cause the throttle not to open fully. There are also a couple of rod length adjustments you can make - the link between pedal and bell crank up front, and from bell crank to throttle on the engine. Checking for full throttle opening is a two person job, but one of those persons need only sit in the driver's seat and push the pedal to the floor. You can check for full throttle opening on the throttle linkage on the engine, and don't need to remove the large rubber boot which connects the two sides of the intake on the engine.

That should get you started.

[Tommy Z]

Thanks Walt, I had completed steps 1-4 as suggested before even taking delivery of the car. Had it up on stands a few times already so I'm comfortable with that part. Your information is greatly appreciated and hopefully I'll be able to figure it out after looking for the diagrams. I'm confident tackling projects when I have step by step instructions with photos and especially if I'm able to find a video. This one is a little intimidating as I know there are parts and pieces that need to be removed to access it. My mechanic yesterday was only able to inspect the bushings with a mirror so I know this one will have some challenging access. If anyone out there has done the linkage/cable/bushing replacement and has any photo documentation I would love to see it! Thanks again Walt.