Throttle Spring Tension

[alchemist]

The throttle linkage on my 1967 230SL sticks at high speed. On the highway when I drive at 65 miles/hr and the butterfly is open and warm, the linkages won't come back and stick. I had to stop and manually retrieve the linage to the original position. I took the butterfly off the engine and took it a part, cleaned it and lubed it as possible. It did not help, so, I thought the spring may lost it's strength. I searched for a similar spring and I bought the spring you see in the pic. This new spring has more strength than the original and made the accelerator hard to press. I wonder if anyone faced a similar problem and if anyone recommend a spring comparable to the original factory spring.

[rwmastel]

Did you lubricate every ball & socket joint in the linkage?  With what lubricant?

[Pawel66]

There are two return springs for linkage:
1. At the firewall, PN    A 186 993 18 10, about $20 at dealers
2. At the throttle: PN A 110 993 17 10, about $3 at dealers

Do you have the one at the firewall?

I am not an expert, but I think fixing sticking linkage should not be via installing stronger spring. In my case the linkage was sticking at the gas pedal lever at the firewall - the cross shaft that goes on the firewall was sticking against a rubber holder of the brakes line.

But I think in such case it is good to dismantle the entire linkage, clean all the joints and hinges and lubricate them. It is while paying attention not to change any distance (if you have recently done the linkage tour) or to do linkage tour while you are at it.

The shaft I mentioned, the one on the fire wall has two hinges that may get dirty - just for example.

Sometimes the constant speed solenoid sticks - if you have it.

[alchemist]

Thank you for all contributors. I have all joint, sockets and balls are cleaned and greased. I will purchase the original 2 springs from the dealer and try again.

[rwmastel]

I have all joint, sockets and balls are cleaned and greased.

Everyone, what is the consensus on lubricate for linkage?  I've seen ATF mentioned a lot (was my first guess), but I've also seen dry graphite mentioned.  I guess the powder type in a small bottle that you "puff" into a lock cylinder?  I guess the concern with grease is collecting abrasive dirt.

[Pawel66]

Thank you for all contributors. I have all joint, sockets and balls are cleaned and greased. I will purchase the original 2 springs from the dealer and try again.

Then, having gone through similar trouble, if springs installation does not help, I would really try to carefully determine which part of linkage is sticking (by disconnecting it in various places) and/or is there really nothing in the way of moving components. Including carpet and kick down switch (if you have one).

[wwheeler]

I don’t think I would use grease. It holds dirt and no way to flush out. If this was a sealed cavity, maybe. Plus grease is typically used for heavier loads.

I use motor oil and just put a drop or two once a year with a needle syringe. The new oil should flush out contaminants and corrosion. Dry graphite is a possibility although not sure how long lasting it is on something that moves so frequently.

Just my thoughts.

[TJMart]

Thank you for all contributors. I have all joint, sockets and balls are cleaned and greased. I will purchase the original 2 springs from the dealer and try again.

Don't forget to check the linkage that is underneath the intake manifold. You will see a rod go through the intake manifold from the engine. There is a plate that rotates that is connected to the engine. There is a plastic part that assists with the rotation. That may have broken. You will have to get under the car to get to it. Disassemble it, Clean it thoroughly and lubricate. I also use motor oil. With the original new springs that should make all the linkage work properly.

Tony

[Kevkeller]

Can you disconnect parts of the linkage and move the different parts to try to isolate?

[paults1]

Automatic Transmision oil is the best to use, It sicks on the ball joints for a long time. This was recommended on this site years ago.