Driver's seat back problem

[Ludovicmeffre]

My driver's seat back tends to tilt on its own while driving. I took everything apart and sent it to a repairer, it seemed better but the problem started again.
Do you have an idea? everything looks ok, the threaded bar looks fine. Should we change the spring inside?
My car is SWB 1968
Thanks in advance

[Ludovicmeffre]

Here pictures

[911int]

Hello Ludovic,
I think the problem is the damage of the toothed shaft. On this shaft the locking wheel slides when activated by the lever. If it is blocked by damages as you see on your shaft the two teeth wheels, locking the backrest, have not enough contact and the possibility is given that the backrest falls down.

Michael

[Sf66]

Hello Ludovic and Michael,

I have the exact same problem on my 68 L. I've already opened the mechanism twice but I didn't try to clean the toothed shaft or check the condition of the splines. I'll try ! Thanks for the hint.

Stéphane

[Ludovicmeffre]

Tell us when done

[911int]

A picture says more than 1000 words, here the mechanism closed



and opened



so if the teeth of the shaft are damaged, the locking part is enabled to slide freely back in its position.

Other reasons for the issue are a not exact guided lever, or a damaged spring bringing the lever back in its position.

Greetings
Michael

[Scott A]

One common problem is the hook can slide in the direction of the arrow. Which it shouldn’t do.
Then the hook is not in the slot, and the teeth don’t have spring pressure to lock up.

See if you lever slides, and then if it does, find a way to stop it.