Yes, John @ TRE did. Hence, where the mm measurements of the gears come from.

 

for the '05 IX 4th and the '06 IX 4th? I can't remember, it was earlier in this thread. IIRC the part numbers were different, but the paired gear was identical, meaning same width (14mm).

edit:
I just searched, it was posted in the Track ****** thread, one of the last 3 pages (sorry I forgot to copy/paste the thread link).
the input shaft gear's part number is identical, so for the output shaft gear, though they have different part numbers, must match the same physical size and shape.

 

Different part numbers = different parts. Maybe different material or strength. Something has to have changed otherwise they'd have the same part number.

 

That is entirely possible, but which of the two 4th gears is failing more frequently, input or output? If it's the output gear that keeps failing, then maybe the new output gear is more heat resillient somehow.

I'm no metallurgist, but I wonder how much more heat/stress resistant you can make transmission gears, moreso than they already are.

 

Absolutely positively untrue. Different part number does NOT automatically = different part. What is your proof?

It's not uncommon to have a part number updated or altered on the exact same part for a different model year or model revision.

 

Well, I don't know for sure that or other car manufacturers will use different numbers for the same part which they produce or use internally. But as an engineer and machine designer for more years than I'd like to admit, I can tell you for a fact that having different numbers for the same part is a very bad idea and can cause a lot of expense and confusion. It's not as bad as having different parts with the same number, but bad anyway.

Having said all that, I'll admit that parts can be standard such as some bearings, gears and pulleys. For instance a ball bearing # 6012 is a 90mm o.d. x 60 mm i.d. and 18mm wide. However, different manufacturers will have their own part number for it. The same is true for spur gears, timing belt pulleys and a myriad of stock mechanical components. Some transmission gears, bearings and spacers might well follow under this condition.

 

Oh I understand this, I work at a manufacturer and we make our own parts. I'm just going by common sense until proven otherwise.

I believe the input gear is the same.
My proof is that I have absolutely no reason to believe they HAVE changed it, considering it's still apparently the same part number.

I believe the output gear has changed.
Why? If the part is identical in supplier, material, design, manufacture process, treatment process, and assembly process, I will believe your statement. However, until proven otherwise, I will continue to believe something about one of the above elements has been altered in some way, and would justify a different part number. Better or worse, I can't say.

I have seen all of these situations happen, unfortunately from the same manufacturer...
identical parts with different part numbers
different parts with identical part numbers
upgraded parts with identical part numbers

ideally...
different parts with different part numbers from the same manufacturer
even if the parts are upgraded and 100% interchangeable, it doesn't matter. This could be from an fitment and design change, different supplier, manufacturing process change, whatever. All it means is that the parts are not identical in every way. This is for an ideal world as silverEVO8 said.

 

what
you mean noone out there has a rockwell hardness tester?
where are all our armchair engineers...

 

Correct on for 4th gear on the input shaft. However, there is no part number for 4th gear on the output shaft. I checked in the USA and in Japan. The output shaft comes as an assembled unit with all the gears, etc on it. The part number for the '05 MR and '06 MR output shaft is the same, so there is no difference in 4th gear on the output shaft either.

 

I have several hardness testers and metallography equipment. I was trying to get a fund together to buy a new output shaft 4th gear to compare with razorlab's broken output shaft 4th gear, but the project kinda came to a halt when I found out that its impossible to get 4th gear on the output shaft by itself. I could compare razorlab's broken output shaft 4th gear to a new input shaft 4th gear, but it wouldn't be a one-to-one comparison. There's a possibility that the input shaft 4th gear and output shaft 4th gear were not manufactured in the same way.

 

Why doesn't someone call up Aisin and ask?

 

im building a trans cooler to see if this aids in longevity, i may install a probe to measure temp before and after install, but thats alot of work hee he jk

cb

 

^^you making kits to sell or just for yourself?

 

i can answer that better when i get vendor status!! which will be any day now!

cb

 

^^^ Seriously, you have a solution to this issue.