I got my rebuilt 6spd back from TRE and installed finally and Jon@TRE sent me back my broken 4th gear as I requested. I measured it so everyone can see just how small this gear is. Honestly, I have a new found appreciation for gears, I have no idea how something like this can hold the power these cars can put out.









For the back-story on how I broke 4th see the whole thread here: https://www.evolutionm.net/forums/sh...d.php?t=210221

 

sweet pics. the specs say its only 14mm wide, i had no idea the actual gear was that small though.

 

"he just a little guy"

Hey Razor how's the tranny cooler coming?

 

I have access to a microhardness tester and optical metallography equipment. If you want to send me your busted gears, I could get some measurements on the hardness and get a picture of the fracture surface. It would be interesting to compare the hardness to the hardness of a new 4th gear. The fracture surface might provide a clue as to the mode of failure (e.g., fatigue crack growth, pure cleavage fracture, etc).

 

So how much abuse will an MR take before that happens?

 

reason # 57809213 to run stock type fluids

that and don't sit out lapping for more than say 30 minutes

good info man.

 

I'm trying to figure out where to mount the pump and cooler currently.

 

I'll ask Shep to send me some goodies, too, for comparison...or rather, to reinforce the issue.

 

man, it IS small... I think it would be really interesting to see the microhardness testing done to get some more detailed forensics.

edit-
man I really wish Mitsu would have gone with straight cut gears on this one. it would add probably 20-30% more beef to the actual cross section of the teeth. the way they're angle cut makes them significantly leaner.

 

Warr and Razor,

How much track time or days did you guys do before this happened?

 

10 events or so, 32,000 miles. No drag racing, launched 1 time a long time ago.

Now that I think about it a bit more, I think it was less then 10 events, maybe 8?

 

It's funny you say that because John Mueller (over on SoCalEvo) spent some energy talking about how (and I'm paraphrasing here) "You deserve what you get if you run the stock fluid."

Then again, he recommends BG2 which I've heard is mediocre for the 6 speed. Honestly, who the heck knows.

 

Jon@TRE recommends BG2 as well. I will also be trying out NEO RHD

 

didn't both you guys KILL your tranny on that stuff?

thats enough to tell me to stay away from it.

12 events on mine, the time bomb must be ticking. Again, i think we're all in the same power range also, if anything i'm a little low.

Normally if im out for 25 minutes or so, unless i'm just cruising, i've pretty much heated the tires to the point of just a bit too hot, and it's time to come in anyways. Again, taking a fan and having electrical at the tracks is great

 

Very interesting, thanks!