Jump to content

5 gear gearbox with overdrive conversion.


Recommended Posts


My name is Wouter and I am from Belgium, I was looking to do a conversion to 5 gears with overdrive for my c303.
i would like to drop some engine speeds for cruising and also for noise reduction and fuel economy.
I'll try to show you what I do.

I started with a gearbox from a c306, these have a 5-speed shift pattern type: ZF S5-18/3
Then I also bought a gearbox from a Maserati Biturbo, which then had an overdrive of 1-0.791


I got both apart. the difference between the gearboxes is: 5 the gear is in a different place.


they use a different syncromash lever used on the top instead of the bottom. The 3rd and 4th of the c303 and 3rd and 5th of the maserati have swapped places. for that I will have to convert the shift arm and syncromashes from the maserati box to the TBG box. I'll try to rebuild the front half of the gearbox so I don't have to do the tapping again. There is also a spring-loaded ball that holds the shift levers in place. this ball is on the other side of the box.



All I have to do is level the top of the maserati box once. there is room for this. to be continued.... Wouter



  • Like 3
  • Thanks 2
Link to comment
Share on other sites

  • 3 weeks later...

Nice! Looking forward to see the progress.

Wouter, would you mind uploading the pictures directly to the forum instead of the links? Way to many cool threads gets old where all links to the pictures are dead.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...