A friends car pushing over 700 hp destroyed his B series transmission when he was on the dyno. I'm going to do a project for my FEA class (Master's Candidate in Mechanical Engineering, UTPA) where I do a Finite Element Analysis (FEA) on the main/counter shaft and gears where I try to simulate on a computer the amount of torque it would take to destroy the transmission and try to match the dyno numbers.

Here is the car:




Here is an example of what happened to the transmission after a dyno session:










So pretty much using Computer Aided Design (CAD) software I want to create the main shaft and counter shaft assembly using Solidworks.

So my question is does anyone know what material these gears are?
Is it steel? Aluminum? Is it cold rolled? Hot rolled? Forged? 1080 steel? 4020 steel?

Can anyone on here help me out on where I can find the material properties of a b-series transmission, or point me to the right direction?

Also if anyone knows where I can get the actual specs of the gears and main/counter shaft that would also be a big help.

Not just on what the gear ratios are, but the diameter of the gears and the size/specs of the gear teeth so that I can draw this transmission using CAD.

Any help on this or just point me to where I can find this information would be greatly appreciated. (I've already searched online and found a lot of info on gear ratios, tranny codes, etc. but no real information on what would actually help me draw this thing using CAD)

 

You can try to contact MFactory as they make Honda aftermarket gears and may know. You can also try H and A Transmissions. They rebuild Honda trans for the public and dealerships....

 

also Synchrotech

 

Forged SCM420

 

Thanks for the quick response! That's all I need to put in the program, and it automatically generates the material properties for that material, young's modulus, Poissons Ratio, UTS, yeild strength, etc.

Right now im in the process of taking measurements of the main/counter shaft as well as the gears pitch, diamter using calipers so I can start to draw this assembly on CAD.

 

This is what I got so far...



This is just the drawing in the works, still need to actually conduct the FEA.

 

Presented and the Professor liked my presentation. The whole presentaion was 39 slides long, and here i'll post the gist of it. But found out that running 500 ft*lbs of torque (and assuming you have a brand new transmission) that the 4th gear most likely will not fail.

But seeing in when the mesh was divided by 6 at the area of interest, you see that the Factor of Safety is about 1.039478, so the 4th gear is very close to its failing point. But under fatigue it is probable that a transmission will fail or is very close to failure under that load.

In the slide you can see the numbers for the displacement of the gear, as well as the stresses it's undergoing using the Von Mises criteria.

 

Just came here to say although NO ONE responded (possibly due to not understanding all the information). Bro cooked with all of this.

this entire documented write up is a gold mine for information. For anyone who may stumble upon this- A safety factor is just a comparative number between the amount of maximum stress an object can handle and the maximum amount of stress it will see where it is being used…

So,

A safety factor of 1.03 means that **** is gonna break.

1.5 means it won’t break right away and when you go pass 2.0, you can be getting ready to jump into high cycle fatigue models (meaning it lasts a long time under use).

So to summarize, the material Honda uses in their manual transmissions is the problem. it could possibly be due to intentionally designing for the counter and main shaft to be stronger than the gears, paired with manufacturing costs overall. But to the non-engineering minds who don’t fully understand what all of this information means, the translated conclusion is…

If you want a better transmission around similar power levels and don’t know if you should go straight cut or not, you can keep a helical setup, you just need to make sure that the material used for the gears has better characteristics than the one listed. (Forged SCM420)

Also, micro polishing can help distribute forces across the surface area of the gear better, meaning- since the max load is 500 lbs of torque, imagine 500lbs of torque that you have to lift with your entire hand, vs your index finger. Since your hand can spread the forces better, it’s less strain on your body. It a similar concept for gears. Good luck on the quest to stop breaking those trannies!