New Linkage Setup for Downdraft Webers.

[djwarner]

My 240Z had dual downdraft webers when I bought it with a linkage that never quite worked right. The setup had a 5/16' shaft that ran from the stock rear linkage bearing, through the ears on the balance tube for the OEM linkage to a rod end mounted ahead of the forward carb linkage. Three arms connected to shaft connected the two carburetors and the throttle pedal linkage.

This setup was subject rattling at the balance tube ears and transmitted vibration to the pedal. I was also concerned about potential for binding as the engine flexed in the motor mounts.

After looking at the OEM setup, I thought about making bearings to support the shaft at the balance tube ears. I found that two pieces of brass tubing 3/8" OD x .014" wall and 11/32" OD x .014" wall stepped the 5/16" shaft up to ear diameter quite nicely and made a neat sleeve bearing spanning the gap between the ears.

But when I ran the shaft through the new bearing, I found the aft linkage bearing did not line up. This was not an important issue in the OEM linkage as there was a U joint (now missing from my car).

The original weber linkage rod was prevented from shifting fore and aft by c-rings on either side of the front rod end. Besides the occasional slipping that altered alignment, it frankly was just not that rigid.

So I ended up buying a diecast low speed U-joint and 2 set screw locking collars from McMaster-Carr for $15. This is what I ended up with:

Edited October 24, 2013 by djwarner