S5 n/a transmission into S4 n/a, which crossmember to use?

[need RX7]

I may be getting a hold of an S5 n/a engine and transmission to swap into my S4 n/a. I was looking on Mazdatrix, and noticed that 2 different transmission crossmembers are offered, one for S4 and one for S5. Which one is required to mount an S5 transmission in an S4 car? Does the transmission or the chassis dictate which mount to use?

[TitaniumTT]

I would venture to say that it's the tranny that dictates it. I don't believe that the chassis changed, but the tranny did soooooooooooooo

[need RX7]

This guy better include the crossmember with the trans, I'd really like to avoid dropping $75 on one :rofl:. I guess I could always get a used one...

[Max777]

if you have an S5 trans, you need S5 cross member. I would also get new mazdaspeed trans mounts. They fit on the cross-member and are a bitch to replace later. Transmission mounts are pretty damn cheap, so I would recomend it.

[Tanj!]

As mentioned. S4 transmissions need S4 cross members and S5 transmissions need S5 cross members. I would also recommend you replace the mounts while you are there. Inexpensive to do and worthwhile as the originals are typically shot.

[Fidelity101]

As mentioned. S4 transmissions need S4 cross members and S5 transmissions need S5 cross members. I would also recommend you replace the mounts while you are there. Inexpensive to do and worthwhile as the originals are typically shot.

mine were twisted and cracked when I took them out

[need RX7]

Yeah I'm planning on getting new mounts for sure (motor mounts too).

[Akagis_White_Comet]

Sorry guys, but this has come up several times on the 'other' forum. I'm going to assume that you are referring to a manual transmission and not an automatic.

If you refer to the RotaryResurrection articles, it will become clear: the body determines what crossmember you need, not the transmission. The center stud on the transmission will line up fine, but the passenger side bolt holes on the crossmember are different between s4 and s5. S5 is flat on both sides while S4 has a steep angle on the passenger side. The center hole where the transmission stud goes through is in the same place either way

S5 looks like this -\___/-
S4 is like this -\___/\

Hope it clears up any confusion

[Black91n/a]

That's wrong, I've put an S4 NA and an S4 TII transmission in my S5 now and you NEED to use the crossmember that matches the transmission, not the body. They will all bolt to the body just fine, but you won't get an S5 crossmember on an S4 transmission or vice-versa.

Do yourself a favour and get a new crossmember and 2 new Y blocks, as the old rubber parts will be shot and in need of replacement anyway.