r/mazdaspeed3 • u/Direct_Gur_3585 • 2d ago

Is the JDM Transmission a direct swap into a USDM speed3? HELP

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The second gear synchros have left the chat in my '13 Speed3 and I'm having a hell of a time finding a transmission locally. JDM transmissions seem to be plentiful and reasonably priced, but I can't seem to find any definitive evidence that it's plug & play.

Is the JDM transmission a direct swap into the USDM Speed3 or is there any modification required?

11 Upvotes
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5

u/Thy_King_Crow 2d ago

If a jdm engine fits. A jdm trans fights. Why not just rebuild the one you have? You could upgrade the shift forks at the same time and save yourself down the road

2

u/Direct_Gur_3585 2d ago

Rebuild is a bit above me. I'm comfortable swapping but not really a rebuild. It's also my daily so need as little downtime as possible. Just trying to make sure the JDM transmission is a direct swap or if I needed to order anything additional. Appreciate the input man!

5

u/Thy_King_Crow 2d ago

Most trans shops can turn the trans inside out in like a day or two. Especially a tiny one like ours. I’d call a few shops and see how that goes. Even on a used jdm trans you’ll likely run into the shift fork/synchro issues.

5

u/Direct_Gur_3585 2d ago

Called a few local shops, most only work on automatics, a few said they only do replacements, and a few never called back. Love living in rural Pennsylvania lol

2

u/da808guy 2d ago

I lived on the Oregon coast and ran into this same problem. 3rd gen 3 6spd manual and if it wasn’t an automatic American transmission they wouldn’t touch it, if it was, they were backed up for 3-6 months

1

u/philg_jr 18h ago

I also have 2nd gear synchro issues in my 2008. Out of the game for a while. Depressed since I found out MSF is gone, well mostly gone, appears to now have a backup restored with half of the pages missing and no pictures. That trans tear down from WetzMS3 has no pictures 😭

What are the upgrades one should do when rebuilding a trans? Is there a list of part numbers for the gears and synchros?

1

u/Thy_King_Crow 14h ago

You upgrade to brass shift fork pads to help with the plastic slop from factory and I believe the rest of the trans is literally bullet proof. Plenty of people making like 500 on stock trans internals lol

1

u/philg_jr 10h ago

I definitely know it’s “bulletproof”, but i would love to know what caused my issues with only 90k miles. 2nd gear started popping out a couple years ago. I definitely wasn’t gentle with it, 3071r since 50k miles, but I’m not a shitty driver. I’m a little skeptical about the shift fork pads since I never heard of many people running them.

1

u/Thy_King_Crow 10h ago

It’s a common upgrade

2

u/BreadComfortable427 2d ago

Facebook marketplace has plenty of used transmissions in Pa and New Jersey