i want to use a b18 diff in my b16 since i blew my b16 diff, i was wondering can i use a b18a or b diff on a b16 would i have to use my b16 ring gear on the b18 diff and if so are they interchangeable????

 

Yes you can use a B18A or B18B differential on your B16 but you will need to reuse the B16 ring gear. The B18A and B18B ring gear is a different ratio than the B16 and is not interchangable.

 

so what if i use the b18a/b18b ring gear and finial drive in the b16 trans will it fit?

 

You can use the 4.266 countershaft and ring gear from a B18A or B18B YS1/Y80/S80 transmission in a B16 S4C/S21/Y21 as long as you use both as a match set. Do not mix the parts because they have a different pitch to the gears. Even though both countershafts have 15 teeth, they are not the same. The B18A/B18B 1992-2001 will have two ID marks on the gear sruface of the countershaft and the B16A/B18C (4.40 ratio) will have three ID marks on the countershaft.

Hope this helps -

 

ok so in a set by that you mean using the whole b18 diff in the b16 along with the final drive , or using everything in the b18 as in gears and all ?? in the b16

 

The B18A/B18B use the same open differential as the B16A. The ring gear bolts on to the differential and either the LS 4.266 or the B16A (hydro) 4.40 RG will bolt to this differential since they both have a 109.8mm diameter hole. The countershaft is the shaft that connects to the ring gear and this shaft must match the ring gear. You can not use a B18A/B18B countershaft with a B16A ring gear or a B16A countershaft with a B18A/B18B ring gear. The C/S and R/G must both be from the same model (Match set). The gears on the shaft can be reused but do not mix match them either.

 

Meaning, use the diff, ring gear, and countershaft all from the B18A/B if you want to use the B18A/B diff, but don't have the B16 final drive set. The gears will lengthen with the 4.266 final drive of the B18A/B though.