I drive a 94 FD. My transmission is starting to go so I've been looking around for a replacement.

I was told to get a JDM tranny because it is better.

Can ANYONE explain to me the difference between the two AND if it ACTUALLY is better, can you tell me what to look for when purchasing?


Thank you!!


Andrew

 

I see no significant difference with the JDM transmission, other than the 5th gear being a bit shorter.

Stick with a stock USDM tranny.

 

Thanks for the quick reply Cptpain!

 

The big advantage to the JDM transmissions is you can easily find VERY low mileage transmissions for a very reasonable price. It's almost impossible to find US transmissions with low mileage, and mileage is what makes all the difference on a trans.

I have one in my car, after installing it I immediately noticed it shifted better, ran quieter, just everything better.

You can pick them up around $300-350 which is a steal.

The 5th gear is different and will bring your cruising RPM's up a bit, about 200-300 RPM, which is acceptable.

But, save for the 5th gear, they're IDENTICAL.

Dale

 

Dale! Good to hear from you. How can I tell if it's a Jdm or us one visually (before purchase)

 

No way to tell as they are identical. Most times they will be marked as such by JDM engine importers and they'll typically be obviously clean and nice with low mileage.

Search on Ebay, they pop up all the time.

Dale

 

You are in Cali so check with Japan2LA on the forums. He is typically a good resource for that type of item.

 

as dale clark said.. about the cruising rpm
i have a jdm fd and the doing 120-130km/hr on the hiway .. my rpm is around 3200 to 3300

 

3000 rpm at 80 mphs, vs 3000 rpm at 70 mphs with a jdm. Roughly, in 5th

 

don't the jdms also have upgraded synchros and shift select spindles?

 

Well you could put it in 5th gear, turn the input shaft and note how much the output shaft turns.

The later JDM transmissions are also reputed to use single piece synchros in 1st and 3rd gear. The USDMs use double-cone synchros on 1st, 2nd, and 3rd. I haven't pulled one apart to confirm this yet.

 

jdm transmission has the 430 gear ratio , pick up is a lot faster than the US 390 but lower top speed

 

those ratios are the diff ratios scottyR

 

lol thats what i meant to say (Diff ratio) my bad !

 

Lets clear up some generalisations.

Not all JDM gearboxes have the .762 5th gear. Only the JDM FD's that had 17" wheels (and 4.3:1 diff) got those boxes, and that rules out tens of thousands of JDM FD's.

You're chasing an RS, RZ, Spirit R gearbox if you want the .762 fifth. Everything else got a .806 fifth.

 

My copy of the 1994 factory workshop manual, page TD-7 states that 5th gear ratio is 0.719:1.

 

Mines been acting up to. Just picked up a new to me JDM trans.
Good luck with which ever way you decide to go.

 

Yeah, your US 1994 FD workshop manual has no info re: what the ratios are in JDM FD's.

JDM means Japanese Domestic Market. Your manual is only accurate for USDM FD's.

 

i have the .806 jdm tranny in my fd. i only changed it to get that shorter 5th gear. car pulls like an animal all the way to 180mph now. the jdm tranny is better all the way around to me, lower milage, cheap, and the short 5th makes it another power gear rather then say an overdrive that the usdm is. only disadvantage is when cruising you are about 10mph under at the same rpm. but keeps me cruising at the speed limit as its at around 3k right around 70mph.

 

The 3.90 is for automatics. Manual USDMs have a 4.10 final.

 

Gomez,

Sorry, I thought you meant "Everything else got a .806 fifth," not "All other JDMs got a .806 fifth." My bad.

 

Cool.

In this case, "everything else" means Type R, Type R Bathurst, Type R Bathurst R, Type RB, Type RB-S, Type Bathurst X, Type RB Bathurst, Type S, Type X, Type RII, Type RII Bathurst, Type RB Bathurst X and the last limited edition sold....the Type R² LE.

I may have missed one or two. As you can see, the great majority of JDM FD's did not have a .762 fifth gear.

 

I had an rhd R1, and it had the 5th gear. I actually prefer the jdm tranny over the North American version.

I now have a lhd car so if the tranny ever goes I will undoubtedly be putting in a jdm.

 

Changed to a JDM tranny a year or so ago.
Biggest advantage was the low mileage, plus the Cost was cheaper
than repairing the stock one. Extra benefit, came with the shifter which
also had lower miles on it and came in handy as a replacement.

 

I have and love my combo, USA trans with JDM .806 5th and the 3.909 diff.
Makes 1-4 a little taller to reduce tire spin in 1st and second plus a power 5th gear.

Remember the stock engine only had 225 whp and now many of us are at or over
400 whp. We need taller lower gears..