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Discussion Starter #1
I'm sure many of you know about the recent 6 speed "MR" transmission sale. I'm sure some of you know that those of us who have 6 speed US spec VR4's will need a 5 speed rer diff in conjunction with the 6 speed MR transmission. Someone brought to our attention that you can change out the ring and pinion gear on the MR 6 speeds and swap in a ring and pinion gear from a 5 speed to match the US spec 6 speed rear end. I would MUCH rather do this than replace my rear diff! Who knows anything about this or has any experience?? Also, where can the 5 speed ring and pinion gears be purchased to achieve this?? Thanks all!
-Jordan
 

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Captain Slow
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I can't really help you with your question, but it's probably easier to just swap in a 5 speed rear diff. I did this a couple of years ago. The rear diff. probably takes a couple of hours. It's one of the easier jobs on these cars.
 

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Verified Hitman
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The Toy Maker
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A long while ago, I had my USDM 6 speed converted over to JDM gearing. I still have my USDM parts to convert it back to USDM gearing if I wish. I even still have my old 6 speed rear diff. To make the JDM transmissions work, you would either need to swap the rear diff, or the ring gear. In the box of parts I have that has my old USDM gears, there is a rod thingy with a gear at the end, and a giant ring gear too. So whatever the technical names for those are is what you would need of a US market trans.

Anyway, I think stating the same thing twice for me in one post is enough. :)
 

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If I'm reading this right, you're talking about swapping the final drive gears in the transaxle..?

If so, no you cannot use 5 speed gears. The tranfer cases are a different ratio. You must use gears from a 6 speed.
 

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3S Obsessed
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A long while ago, I had my USDM 6 speed converted over to JDM gearing. I still have my USDM parts to convert it back to USDM gearing if I wish. I even still have my old 6 speed rear diff. To make the JDM transmissions work, you would either need to swap the rear diff, or the ring gear. In the box of parts I have that has my old USDM gears, there is a rod thingy with a gear at the end, and a giant ring gear too. So whatever the technical names for those are is what you would need of a US market trans.

Anyway, I think stating the same thing twice for me in one post is enough. :)
enollava
I completed the same conversion as well. Bought a new JDM Ring and Pinion gears for the trans-axle from RalliArt and picked up a used 5Spd rear-end for about $150. Took that 5spd apart and had the housing powder coated black (tuned out beautiful). Re-assembled, installed new bearinngs and a Kaaz LSD in there.

So...folks can use all this resent influx of JDM transaxle availability as a brand new excuse for more 'upgrades' !

Dan
97VR4
 

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I can't really help you with your question, but it's probably easier to just swap in a 5 speed rear diff. I did this a couple of years ago. The rear diff. probably takes a couple of hours. It's one of the easier jobs on these cars.
Ditto..
 

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Discussion Starter #8
I posted wrong my bad. What I meant to say was throw in a ring and pinion gear from a US spec 6 speed. This was posted in Jeff's first thread reguarding the tranny sale and the point of the 5 speed rear end swap was brought up after we found out they would be JDM spec.

''Heres a simpler version. Just change out the ring and pinion gear attached to the front differential in the tranny and you have a USDM 6 speed. The gears inside the transmission are the same 1-6 etc. Whats different is the ring and pinion. When I bought 'MR' gears, it was one ring gear and a new pinion gear. Both can be easily swapped from your existing 6 speed to make the jspec tranny into a US geared one. If you already have the stock transmission dropped, its a matter of opening the cases and making the swap.

Sam''

So if this statement is correct, I could just do this and have a USDM 6 speed?? Where can I get these parts? OR...would you guys advise the JDM swap and just throw in the 5 speed rear end for the actual JDM gearing. Long term my car will be 16g powered if that helps some of your guys' opinions. Thanks for all your help! Getting a brand new transmission and t-case for a little over $2k is pretty effing exciting, especially when my syncros are SHOT. Best reguards!
-Jordan
 

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3S Obsessed
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[snip]]

So if this statement is correct, I could just do this and have a USDM 6 speed?? Where can I get these parts? OR...would you guys advise the JDM swap and just throw in the 5 speed rear end for the actual JDM gearing. Long term my car will be 16g powered if that helps some of your guys' opinions. Thanks for all your help! Getting a brand new transmission and t-case for a little over $2k is pretty effing exciting, especially when my syncros are SHOT. Best reguards!
-Jordan
You can probably source USDM Ring and Pinion from the community..I bet there are a number of "dead" transaxles out there with these parts being ok for re-use. Or...you could contact RalliArt and have him (or possibly another source) ship them new from Japan (personally, I know that will be expensive).

As an aside, since you mentioned 16G's...that setup was the reasoning that triggered switching to the JDM gear ratio. I track my VR4 and theorized that a lower gear ratio in that venue would be useful to raise engine RPMs and assist with spooling the larger turbos. I've not been to the track yet with the 16G's..I hope I've not gone too big!...:confused:

Dan
97VR4
 

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Discussion Starter #10
I can't believe I didn't think of just swapping out the ring an pinion from my exsisting 6 speed into the JDM. Darrel move on my part. Can I get some more opinions on wether or not to stick with US spec gearing with my 16g build, or throw in a 5 speed rear end to attain the lower gear ratio for some more torque since it will be a daily. I will very rarely, if ever, be at the track. I'm not even sure if there are tracks in Iowa! Soo many decisions! Thanks everyone.
 

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So do I.

I currently have a 92 5 speed with td05 16gs in it and just bought a jdm 6 speed. I think the shortier lower gears will help with some of the off the line "turdiness" of a stock displacement 16g setup.


Joe
 

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So do I.

I currently have a 92 5 speed with td05 16gs in it and just bought a jdm 6 speed. I think the shortier lower gears will help with some of the off the line "turdiness" of a stock displacement 16g setup.


Joe
I hope you know you also need a transfer case for a 6speed. The 5speed and 6speed transfer cases are different. Good news is you already have a 5speed rearend.
Brett
 

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Sorry to bring back this old thread but id really like to know what exactly has to be done to get the jdm 6 into the usdm 6? It might cheaper for me since I can't find any usdm ones around me.
 

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reason for tickets.......
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Sorry to bring back this old thread but id really like to know what exactly has to be done to get the jdm 6 into the usdm 6? It might cheaper for me since I can't find any usdm ones around me.
Step 1) Remove Transmission
Step 2) Remove bellhousing
Step 3) Remove the ring and pinion
Step 4) Drop in the JDM ring and pinion.
Step 5) Make sure you have a 5spd rear diff.

I thought the USDM ones were easier to find, no?
 

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Does it have to be a certain kind of differential? Do usdm and jdm have different rear diff?

I found tons if websites that sell jdm transmissions for pretty cheap, still couldn't find any usdm 6's. I'm wondering if the total cost to go jdm would save versus the high cost of usdm ones if I could find one
 

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Step 1) Remove Transmission
Step 2) Remove bellhousing
Step 3) Remove the ring and pinion
Step 4) Drop in the JDM ring and pinion.
Step 5) Make sure you have a 5spd rear diff.

I thought the USDM ones were easier to find, no?


I think this is answer is backwards -sounds like the OP wanted to use a JDM 6sp in his US 6 speed setup. Implying he is currently set up with a US 6 speed and has a US 6 speed rear diff.

You basically have two choices if you go read the thread from the begining.

Choice 1 : Convert a JDM 6 speed transaxle into a US 6 Speed transaxl & leave Rear diff alone

Step 1) Remove Transmission
Step 2) Remove bellhousing
Step 3) Remove the ring and pinion
Step 4) Drop in the US Six speed version ring and pinion.
step 5 ) Leave your existing 6 speed rear diff alone.

Choice 2 : Use JDM 6 speed transaxle AS IS in your US 6 Speed setup & Replace Rear diff with USDM or JDM 5 speed rear diff.
-as this option says - you use the JDM 6 speed just as it is - don't change anything but replace your USDM 6 speed rear diff with a 5 speed rear diff.
 

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reason for tickets.......
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I may have misinterpreted. Now we've got directions for both ways. :)
 

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Thanks for all the help. Since you guys are the experts and probably know more than me after a couple hours of research I have one last question (hopefully :p). Im sure the rear diff is more expensive than the ring and pinion, but since im not super confident I think id rather take the second option and just swap the rear unless I could use the ring and pinion from my usdm transmission. Is there any specific 5 speed rear end thats better than any others? If I have to pay for one I might as well have the best one!
 
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