On my build, I decided to go the 6spd/3.6 route. Since then I've had more than one person comment about more strain on the trans since I lowered the diff ratio from 4.1 to 3.6.

Can someone explain to my uneducated self how a lower diff ratio would increase stress on the trans? Didn't make sense to me off the bat

 

When you're traction limited, the amount of torque going through your trans is determined by torque at the wheels. Wheel torque divided by diff ratio = trans torque. Going from 4.1 to 3.6 means 14% more torque at the gearbox output shaft to reach the limit of traction at the tyres.

Once you're engine limited, diff ratio doesn't make any difference to the load on your trans.

 

Makes perfect sense. Went right over my head the first time it was explained. Thank you!