Car Mechanics (UK)

More haste, less speed

- Martin Ruben­stein Austria · Iceland · Belarus

Back in the 1970s I had a Van­den Plas Princess 3.0 with an au­to­matic gear­box that de­vel­oped a leak at the front end. I didn’t have the spe­cial tool to align the torque con­verter to the trans­mis­sion, but I rea­soned that, be­cause the torque con­verter stayed with the en­gine dur­ing sep­a­ra­tion and the trans­mis­sion wasn’t go­ing to turn dur­ing the seal re­place­ment, it should go back to­gether with­out the need for a re­align­ment tool. Bal­anc­ing the very heavy trans­mis­sion on a screw trol­ley jack on a garage floor was far from ideal and, try as I might, I couldn’t get the trans­mis­sion to mate with the torque con­verter.

So I de­cided to con­vert the car to a man­ual gear­box with over­drive. I got all the nec­es­sary parts from my lo­cal scrap­yard and all went well, ex­cept that the last inch or so was tight when mat­ing the bell­hous­ing to the en­gine, re­quir­ing a bit of force. Want­ing to fin­ish the job, I pressed ahead when I re­ally should have stopped to con­sider what wasn’t right.

Once on the road, I started to get a squeal­ing when chang­ing gear and soon couldn’t en­gage 1st gear with the en­gine run­ning. I re­alised what I’d done wrong: in the crankshaft on the au­to­matic, there is a steel bush to lo­cate the torque con­verter and there is never any rel­a­tive mo­tion be­tween the two. On a man­ual gear­box, this steel bush is re­placed by a bronze bear­ing that lo­cates the gear­box in­put shaft, but cru­cially al­lows the shaft to freely rotate within the rear of the crankshaft dur­ing gearchange­s.

By not re­plac­ing the steel bush, I had fric­tion-welded the gear­box in­put shaft to the steel bush at the rear of the crankshaft. I had to smash the bell­hous­ing with a club hammer to get to the clutch bolts to dis­as­sem­ble the mess. That was fol­lowed by a sheep­ish re­turn visit to the scrap­yard to ad­mit my er­ror and get a sec­ond gear­box, fol­lowed by a trip to a bear­ing sup­pli­ers to get a phos­phor bronze bush.

The lesson? When some­thing doesn’t quite seem right, stop and work out why!

 ??  ??

Newspapers in English

Newspapers from UK