Accelerator Control Rod Maintenance


 TR6 Home














One annual maintenance that I've been doing for a number of years is so simple that most people overlook it, yet the impact on "throttle feel" is huge. For the smoothest operating accelerator shaft you should first make sure the shaft bushings are all in place or, better yet, replace them with Art Lip's Kit.

 The diagram below shows the three pieces that I'm talking about. The two red arrows point to three ball & sockets fittings that are found between your two carbs and ultimately work the carb linkage. If they're not properly maintained i.e. cleaned & lubed, they will begin to bind over time. When it gets real bad it will feel as if the accelerator pedal has a momentary blockage that you have to push through.

You can remove these pieces by pulling out the cotter pin and unscrewing the end a few turns to give the ball a chance to pop out of the socket. As you'll see later on there's actually a little spring loaded piece in the socket that helps to maintain pressure on the balls. Once you get these two pieces off you'll be left with the three balls on the bell crank and throttle linkage exposed. The socket on the control rod has a lock nut that needs to be loosened so you can unscrew the socket from the control rod.

Now you can take the socket apart, clean it and pack it with bearing grease. As you can see below, there are four components that come apart and need cleaning. I packed the whole socket component with grease and then inserted the spring and the spring cover. I pushed it down with a small screwdriver to seat it in place. The screw cap goes on next and is left loose so that the ball end can fit in. As you can see, the opening for the ball is not a perfect circle.

Here's what the vertical one looked like after it was cleaned and packed. The red arrows point to the two locking nuts. I loosened these just enough to allow me to unscrew the socket housing. You could even put some duct tape over them to keep them in place so you don't mess up the linkage settings.

Now it was just a matter of reassembling everything. I tighten those end cap screws until they're at least flush with the socket housing. If you screw them down too much you'll feel the linkage start to bind. The most challenging part is lining the screw head slots up with the holes for the cotter pin, especially when you're working blind. Once it's all together, it should look like this and operate smoother then before. Don't forget to tighten the three locking nuts down (red arrows).

If you've never done this before, figure on spending 60 - 90 minutes from start to finish. I can usually get it done in less then an hour. It will be time well spent.