Hey,

I got a problem ordered a complete carbon lined rebuild kit for
my y21 B16A tranny and a Helical LSD from Mfactory.
now to the Problem:
Mfactory sent me the wrong helical lsd, they sent me the one for the b18
with the bigger inner diameter ring gear.
so my B16 4.266 small ring gear does not fit.

as i am in austria and shipping back and forth for an exchange is very expensive, what about if i fit a 4.7FD from the b18 with the bigger inner diameter ring gear in my b16 tranny ?

i guess it should fit or are the countershafts different ?

hope mfactory can help me out for sending me the wrong diff.
already wrote an email to steven.

 

The FD is the ring gear and countershaft together. Yes the countershaft is different. Even if it wasn't you still can't really mix and match a ring gear and countershaft from two different transmissions. You'll get gear whine and have excessive wear.

 

Ok you missunderstood me.
I meant fitting the whole countershaft and ring gear from
A b18c in a y21 tranny, So that i can use the b18 lsd.
Will it fit or is the countershafts different in lenght or some
I know that the teeth are different .

 

Yes, that will work.

 

Ok thats good
What about 1st gear ive heard that you have to use
The itr one is that true or not

 

If you use the OEM 4.785 FD, you will need the JDM 98+ ITR 1st gear, collar, and roller bearings. MFactory makes several different ratios for the B18C that don't require the 1st gear change.

 

Thanks perfect thats what i wanna hear.

 

Just got a quick question since you mentioned "JDM 98+ ITR 1st gear, collar, and roller bearings".
I've got a JDM 96+ ITR 4.4 FD S80 tranny (stamped J4D) that i wanted to convert to 4.7 FD.
I picked up a "N3E" stamped JDM 98+ ITR 4.7 FD ring gear & countershaft with the matching 1st gear, collar, and roller bearings...
Now, can i swap the N3E JDM 98+ ITR 4.7 FD ring gear & countershaft with the matching 1st gear, collar, and roller bearings into the 96 spec ITR tranny???
Would i need to grind something on the casing for the ring gear to clear since it is bigger??
Any info would be greatly appreciated !!!

Thank you!!!!

 

You'll need to use the ring gear, countershaft, 1st needle bearings and collar, countershaft 1st and 2nd gears, and mainshaft from the JDM 98+ ITR trans. Or just order an MFactory 4.785 FD (available in both 98+ and standard fitments).