Sunday, 23 December 2012

The gear change linkage

The gear change linkage

Today recovering from man flu I could not resist opening some of the packets of deliveries accumulated over the week. I found the bits I needed to connect up the gear selector so I spent an hour in the freezing workshop but the effort was worthwhile.

I find the build notes are a bit confusing on this issue, Jeremy  supplies some of the bits preassembled (if you want them) take my advice buy them/ add them to the order. Unfortunately you are still on your own to devise a solution from the tunnel UJ to the gearbox selector rod and linear bearing. This bracket and linear bearing effectively reverses the gear linkage for the Sigma engine and points it forward. All you have to do is find an adequate additional universal joint (UJ), attach it to the rod from the gearbox and then attach the other end to the UJ sticking out the tunnel.

I think Jeremy suggests using the UJ out of the donor car and some 15mm bar and welding the whole thing up. This was not an option for me as this UJ from my donor Puma was f....d. I did however  find extra UJ steering joint in my parts box I had inadvertently ordered extra from RallyDesign RD820F - Group 4 coupling forged steel. RD also supply a splined shaft RD849 which is a 400mm shaft with splines to match the coupling. When the aforementioned bit arrived and after careful measurement, I parted off about 50mm off one end and knurled the first 20mm of the same end so the coupling coming out the transmission tunnel so the UJ could get a grip. I then bored one end of the new UJ with a Mag Drill of 16mm dia to match the rod from the gearbox. All I had to do was file a flat in  rod from the gearbox so a 8mm bolt can be fitted and locking the UJ in place. The only adjustment left now is the UJ coupling at the tunnel. I put all this together in short order and to my amazement the whole thing worked a treat. Perhaps not a Lowcost solution at £18 +VAT but a very robust one I assure you. The positive feel is better than my Westfield with the selector sticking straight ot of the MT75.



1 comment:

  1. When you shift gears, the synchronizes use the force of you moving the shift lever to slow the clutch disk to identical speed because the gear, so after you have interaction the gears, the input shaft goes identical speed thus you do not grind gears.
    Steering Rack