Gearbox Strip - Monday 6th October 2014

"A" Type Gearbox
Selector Forks Removed

Stripped Box Less Layshaft

Today myself and Isaac were assigned to the practice Gear Box task.  I omitted to take an initial picture with the selector forks intact, however this did not affect the overall result which was very successful.  We used a Ford Escort Haynes Manual for the detailed instructions regarding procedure, and a logical and calm process for the placement of dis-assembled parts was firmly adopted from the outset!  Having successfully dis-assembled the gearbox and its component parts, we were then required to ascertain the number of forward gears,

Layshaft (Counter Shaft)

Gear Identification
and Power Flow Evidence

Evidence Calculation of Gear Ratios
(Driven Over Driver x Driven Over Driver)
Gears 1-3, 4th 1:1 Direct, and Reverse

and identify the Reverse Gear and Idler.  We were also required to calculate the individual gear ratios for all gears, and demonstrate knowledge of power flow through the various gears contained therein. Having successfully completed all tasks (so we thought) we then duly re-assembled the components in reverse order, only to find that we were initially unable to engage 3rd and 4th gears (although we should have checked at the outset that the unit was indeed functioning).  However Julian Jones was on hand to give the mechanism a bit of a "nudge" with a pair of pliers, and all gears were proved to engage. We were then asked how many teeth were on the idler gear, at which point (with Julian departed) "Goose" went into a bit of an egoic "strop" (due to it not influencing the gear ratio - which it doesn't - however this is College and we do what we are requested to do)!  I do like to utilise my initiative, and I did happen to have a bottle of tippex in my bag, and the short break in terms of its retrieval from my locker was very much appreciated!  With the tippex applied to the tip of a long screwdriver, I was able to mark the idler gear and count the number of teeth, as very politely requested.  After some further explanation from Carl Black as to further approximised methods of gear ratio calculation, such as counting output shaft turns and input shaft turns, and using RPM, where the calculation is reversed (Driver over Driven), we were then duly signed off as complete to a good standard, and I was then allowed to go to work!  A good day with positive results (until I got to work that is - Nightmare shift)!!! Final Note:  Final Drive Ratios would include another Driven over Driver equation in addition to those taken thus far (to include Differential Ring Gear to Pinion).