Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
techtalk:ref:svcproc24 [2020/08/22 21:21]
hippysmack [Measuring Pinion Gear Runout]
techtalk:ref:svcproc24 [2024/01/22 21:29] (current)
hippysmack
Line 3: Line 3:
  
 ====== Measuring Pinion Shaft Runout ====== ====== Measuring Pinion Shaft Runout ======
 +Check to see if your crank is out of true. The idea is to measure how much the end of the pinion shaft wobbles. ((aswracing of the XLFORUM https://​www.xlforum.net/​forum/​sportster-motorcycle-forum/​sportster-motorcycle-motor-engine/​sportster-motorcycle-bottom-end/​145445-cam-bushing-wear?​t=1578649)) \\
 +Up to .005"​-.006"​ out there at the end of the shaft doesn'​t propose a huge problem. Most motors you measure will show this much. \\
 +But above that is not good. Crank spread is a reality of racing these bikes. The flywheels want to spread apart on the side opposite the crankpin. \\
 +When they do, the pinion shaft wobbles. You get real bad wear on the oil pump drive gear (this is why Buell went to a bronze drive gear). \\
 +Harley never put it in the XL's because they'​re lower powered and it's less of an issue. But still sometimes they grenade and make a mess. \\
 +Pinion shaft wobble also causes teeth to break off the pinion gear, and the pinion bushing to wear, and cam bushings to wear. \\
 +To confirm pinion shaft runout dims, make the measurement as in below. \\
  
 +|Attach a scrap piece of metal to the outside of the gearcase and position a gauge holder on it so it won't move while turning over the engine. ((photos by anachris of the XLFORUM https://​www.xlforum.net/​forum/​sportster-motorcycle-forum/​sportster-motorcycle-motor-engine/​sportster-motorcycle-bottom-end/​160037-bottom-end-rebuild#​post3404527))|||
 +|{{:​techtalk:​ref:​tools:​checking_pinion_shaft_runout_1_by_anachris.jpg?​direct&​300|}}|{{:​techtalk:​ref:​tools:​checking_pinion_shaft_runout_2_by_anachris.jpg?​direct&​300|}}|{{:​techtalk:​ref:​tools:​checking_pinion_shaft_runout_3_by_anachris.jpg?​direct&​300|}}|
  
 +|Install a dial gauge on the holder with the pointer on \\ the pinion shaft. Find the lowest spot while turning \\ the engine over and '​zero'​ the indicator. ((photo by Grind of the XLFORUM))|This setup is made with a piece of angle iron for the magnetic base to stand on ((photos by dezzertrat of the XLFORUM https://​www.xlforum.net/​forum/​sportster-motorcycle-forum/​sportster-motorcycle-era-specific-and-model-specific/​ironhead-sportster-motorcycle-talk-1957-1985/​173328-77-xlt-teardown-and-rebuild?​t=1860581))||
 +|{{:​techtalk:​ref:​tools:​checking_pinion_shaft_runout_6_by_grind.jpg?​direct&​300|}}|{{:​techtalk:​ref:​tools:​checking_pinion_shaft_runout_7_by_dezzertrat.jpg?​direct&​300|}}|{{:​techtalk:​ref:​tools:​checking_pinion_shaft_runout_8_by_dezzertrat.jpg?​direct&​300|}}|
  
 +|This gauge post is threaded into a cover mount hole. ((photos by DirtyCory of the XLFORUM https://​www.xlforum.net/​forum/​sportster-motorcycle-forum/​sportster-motorcycle-era-specific-and-model-specific/​ironhead-sportster-motorcycle-talk-1957-1985/​127032-getting-this-78-back-to-the-way-it-should-be/​page8?​t=1297584&​page=8))||
 +|{{:​techtalk:​ref:​tools:​checking_pinion_shaft_run-out_1_by_dirtycory.jpg?​direct&​300|}}|{{:​techtalk:​ref:​tools:​checking_pinion_shaft_run-out_2_by_dirtycory.jpg?​direct&​300|}}|
  
  
 \\ \\
 [[:​techtalk:​menu|{{:​techtalk:​gototechnicalmenu.jpg|}}]] [[:​techtalk:​menu|{{:​techtalk:​gototechnicalmenu.jpg|}}]]