Finding a solution to breaking gearcases on high power Rs

M

murty

Member
MarkTurbo said:
Standard gearset too :shock: Usually the teeth fall off them before the casing goes :lol:
Click to expand...
I have drag raced the standard box for 7 years and only done the teeth once, I break selector forks more than anything else.


[FONT=&quot] here are some more pics you can get a better understanding of the explosion when i put the end pieces back on[/FONT]


IMG_1987[1].jpgIMG_1984[1].jpgIMG_1985[1].jpg
 
red reading

red reading

Active Member
I have said before the gearbox is stronger than people think, that has failed from the output shaft bearing and gears trying spread when launching, if you look at a stock gearbox the helical cut out gears and the opposite direction helical cut on the gear try to keep the thrust forces equalised, I wonder how much longer it would have lasted if the casing was braced to stop the gear shafts from spreading. Which selector fork do you keep breaking?
 
Dangerous Dave

Dangerous Dave

Active Member
bet that went with a bang..

i was telling danny the other week about my box, i was at a sprint day didnt turn the car off after lunch so the car was running from 12.30 till 6.30 7ish when i got to the digs,

anyway i was putting it in to 1st at around 20mph 90% of the time to get around a cone never let go! sooo this year my misson is to make it look like yours haha
 
M

murty

Member
red reading said:
I have said before the gearbox is stronger than people think, that has failed from the output shaft bearing and gears trying spread when launching, if you look at a stock gearbox the helical cut out gears and the opposite direction helical cut on the gear try to keep the thrust forces equalised, I wonder how much longer it would have lasted if the casing was braced to stop the gear shafts from spreading. Which selector fork do you keep breaking?
Click to expand...
it was a 20 year old casing, and regularly drag raced for the last 7 years i suppose it was a ticking time bomb. We looked at the damage and agree that the damage is the two shafts separating so we built a brace that goes all around the gear box, see how that lasts.

The selector I regularly break is 3rd n 4th. The symptoms replicate to me like stripping the teeth of a gear, as it goes in to 3rd loose all drive, it is easy to think 3rd gear has gone, which leaves me to believe that maybe the infomus 3rd gear failure is often a miss diagnosed selector fork failure failure and the gears are tougher than people think.

I wouldnd advise any one to replicate the damage, as parts are starting to get harder to come by, especially at reasonable prices.
 
warringtonjack

warringtonjack

Active Member
Anyone got anymore info on these braces that are available? I'm currently sporting the fabled OS Giken twin plate / Quaife combo.
 
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