Ah my bad, I was jumping around topics a little - there was someone earlier asking if there was a shop that sold plates to do the LSD upgrade themselves, and I just simply assumed without looking carefully you were responding to that.

Following service manual is a great way for STU guys to get more lock up out of their rear diff - sorry about that. I'll put a link to your post in the first post

 

Thank you, kyoo.

If I said I haven't been guilty of that, I'd be lying.

Yeah, if anyone were increasing the lock up beyond the intended factory limit, I would highly suggest sending it out to have the heavy duty options done.

 

I wish I could find Jon@TRE like u guys does.I've been calling him,left message,and email.no responsed at all.just got tired looking for that guy!

 

Left a message? Ive never actually gotten an answering machine. I just call tues-fri around noon PST. Usually takes a few tries but I can get a hold of him.

 

+1

 

I wrote a response on the website and Jon called back a day or two later. We had a great conversation. I will be getting the 12 plate. Jon's a real nice and knowledgable guy.

 

You're right that TRE does a great deal of work that is not identified in the manual when they do this modification. That work is important, and perhaps critical, to the modification itself.

If you want a comparison, the steps in the manual are what you would get from a factory dealership mechanic reading the manual to return a damaged part to stock operation, which really has no comparison to a TRE modified rear diff.

 

Actually, it isn't like returning it to stock operation. When I removed my diff, two steel plates and two friction plates were side by side, effectively reducing the grip by 50%. That's the way all USDM evos came from the factory. According to the manual, the diff should be set up to have a steel plate between the two friction plates.
Do you realize what your saying? You're talking about custom work that no dealership does, of course it's going to be no comparison between the TRE diff and stock diff, regardless of plate orientation.
I'm simply talking about assembling the diff to specifications, in the manual, that double the friction.

I, in no way, implied that this is as good as or better than their modification.

From my experience, I know that correcting the order of the plates made a world of difference. On street tires, I don't think I would want more lock than what it has now with the plates corrected. I think it would produce too much oversteer, under power. If I was running extremely soft compound tires, I think I would kick it up a notch with the TRE diff and upgrade to the HD parts as well due to the increased force from the tires.

Now at WOT, exiting a turn, when I shift I don't have to correct the steering angle as much, as the rear is already trailing nicely. Its perfect.
You can go overkill as much as you want, it doesn't always make something better.

 

Thats what I have been saying all along as well.

 

i would venture a guess that 95% of ct9a evo owners don't know that the rear diff is not assembled as the service manual instructs - maybe more

 

For some reason I was thinking machining was required for the 12-plate upgrade but now I can't find any info on that. I must have just had things misunderstood in my head. Do any of the offered upgrades from the different companies out there require machining of the diff or the housing?

I sent Jon an email this morning and had a response just a couple hours later. Going down to the shop next week to get some work done. . .

 

It would have been nice if that would be a recall for all ct9a owners by Mitsu of North America.

 

Probably 99.9%. Here's proof that it's installed wrong at the factory:

https://www.evolutionm.net/forums/ev...y-factory.html

 

haha i think you're right - i PM'd one of the mods, i think it may be appropriate to get a separate sticky thread in this section of the forum about how the rear diff isn't assembled properly from the factory - aside from this rear diff mod thread


yeah, maybe just a TSB where evo owners bring in the car and they'll do it for free... would be nice for ct9a evo guys.. i bet if the ct9a came assembled properly from overseas the car would have gotten even more praise for its handling when it first came out

 

When the plates are installed correctly, you will definitely have to change the LSD fluid at 15k or less, depending on how you drive your car, no different than a upgraded/modified diff. I'm guessing they didn't set it up this way because of service intervals, and noise. Which it isn't really noisy, BTW.
I truly think they set it up this way to reduce customer complaints.