So a few years ago I got a t2 transmission to put in my car and I am finely getting around to putting it in. But before I put it in I was going replace the transmissions seals. On the RB site it shows two different seal kits, s4 and s5 t2. How do I tell which transmission I have for sure? I have a part number on top of the bell housing E OC537, anyone have a reference for these numbers? Thanks

 

The cases, one is smoother, has less ribs. Picture one like a checkerboard and the other just a few sections. Google some pics maybe you can see for yourself


Should have specified- s4 is smoother case

 

not quite true as there is several variation within s4 and s5 for the case webbing and thickness, so, have seen the extra webbing on both versions

s4 has a bell housing fixed ( to the rest of the gearbox ) with 8 bolts, s5 has an extra 2

s4 has a flat mounting plate for the gearbox mount,, s5 has a V profile

s4 has a narrower rear section on the gearbox,, s5 is wider at one point,, as it houses an integral balance weight for the output shaft

s4 and s5 use different shifters,, with different threads for the gearnob,, and a different setup for the ball at the bottom of the selector,, one being solid ,, and the other using the nylon cup of earlier gearboxes

some of this stuff can be interchanged between s4 and s5 so you can in effect custom the s5 box to fit in s4 or vichy versa

the biggest pitfall being that balance weight,, that would need to be deleted to fit the s4 tail section ( and its flat mounting point )

 

Just going off the 2 dozen jdm engines i sold back in the day, the cases always matched the series, maybe its a jdm thing that they were always constant

 

If the weight isn't removed could it cause a vibration on s4 trans with s5 engine?

 

I worked with a friend to figure this out.

The S5 has one or two more bolts to the bell housing. The trans mount Y brackets mount to the trans housing differently. S4 from the bottom, S5 from the side.

 

No.

 

So if I did not take the counter weight off the s5 transmission and swap it onto the s4 transmission for an s5 engine it wouldn't cause an rpm related vibration? Just wondering this because I have a vibration problem ever since swapping transmissions, tried to swap tailshafts but did not swap counter weight over and still have a vibration.