Broken layshaft and 2nd gear

[Skrimshaw90]

Had a weird incident this past race where i broke the layshaft in half and also destroyed 3 teeth on 2nd gear. I didnt do anything different, tried to shift from 2nd to 3rd but the car got stuck in 2nd and wouldnt shift into any gear. Pulled the car in and removed the back cover to see that i was selected in 2 gears. Popped them out, loaded the car up and went home. Upon removing the gear set i have found the layshaft to be broken right where 2nd gear is and 3 teeth on the big 2nd gear are gone. What would cause this and what can i do now that i have the gearset out to ensure it doesnt happen again? What parts do i need to service while i have this stuff out?

[Dennis McCarthy]

Had a weird incident this past race where i broke the layshaft in half and also destroyed 3 teeth on 2nd gear. I didnt do anything different, tried to shift from 2nd to 3rd but the car got stuck in 2nd and wouldnt shift into any gear. Pulled the car in and removed the back cover to see that i was selected in 2 gears. Popped them out, loaded the car up and went home. Upon removing the gear set i have found the layshaft to be broken right where 2nd gear is and 3 teeth on the big 2nd gear are gone. What would cause this and what can i do now that i have the gearset out to ensure it doesnt happen again? What parts do i need to service while i have this stuff out?

Send it to Scott Taylor....

https://www.sy-gearboxes.com/about-tre

[Dee]

Had a weird incident this past race where i broke the layshaft in half and also destroyed 3 teeth on 2nd gear. I didnt do anything different, tried to shift from 2nd to 3rd but the car got stuck in 2nd and wouldnt shift into any gear. Pulled the car in and removed the back cover to see that i was selected in 2 gears. Popped them out, loaded the car up and went home. Upon removing the gear set i have found the layshaft to be broken right where 2nd gear is and 3 teeth on the big 2nd gear are gone. What would cause this and what can i do now that i have the gearset out to ensure it doesnt happen again? What parts do i need to service while i have this stuff out?

you may have a problem in the diff maybe the spider gears failed, this happened to me in my gearbox (swift 016) and I was stuck between gears on the Corkscrew at Laguna Seca, not a pretty sight my first gear lost two teeth.

[Dee]

Send it to Scott Taylor....

https://www.sy-gearboxes.com/about-tre

don't you mean Scott Young

[Bob Wright]

Send it to Scotty...you don't generally break a layshaft unless something major happened in the box. They are too expensive to fool around with unless you have intimate knowledge of them. Breaking a lay shaft may affect bearings and other components, not to mention teeth floating around the box.

Having said that, if you broke a tooth or three on second gear (you didn't mention what box you have but this holds for either a LD200 or MK 9) and jammed a tooth in the gear flexing the layshaft, it could break.

[sflaten]

Last season had a couple similar issues. Memorial Weekend races at BIT broke layshaft similar to your description exiting turn 6. Felt like it would not go into gear. Drive it back to pits and turning off the track lots of bad noise (teeth off gears), Repaired and raced 4th of July weekend with no issue. Labor Day weekend was in qualifying run and at exactly the same spot on track it seemed like same problem again and could not get into gear. Returned to pits and even more bad noises, This time it broke the shift fork rod right at the top of the threads in the rod.
Each time the gears were stuck between two gears and took off many teeth on the gears. Had Gear Daddies repair both times and it seems to be working now. We looked thru all sorts of potential problems. Apparently the shift fork threading is an issues that shows up on occasion that might be the source. Good to know if you get any other ides or origin with your equipment.