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

Tanj! · 06-01-2009, 11:07 AM

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 · 06-01-2009, 02:19 PM

Quote:

Originally Posted by 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.

mine were twisted and cracked when I took them out

need RX7 · 06-01-2009, 08:24 PM

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

Akagis_White_Comet · 12-28-2009, 04:59 AM

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 · 01-01-2010, 07:02 PM

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.

06-01-2009, 08:24 PM	#3
need RX7 Clean S4 Nutswinger Join Date: Mar 2008 Location: Sterling Heights, MI Posts: 485 Rep Power: 18	Yeah I'm planning on getting new mounts for sure (motor mounts too). __________________ -Ted -1986 Mazda RX7 Sport [DD/beater]: engine finally let go at 205k. parts car status. -1986 Mazda RX7 base [resto-mod project]: S5 n/a swap in progress.

06-01-2009, 11:07 AM	#1
Tanj! Rotary Fan in Training Join Date: Feb 2008 Location: Dallas, TX Posts: 44 Rep Power: 0	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.

12-28-2009, 04:59 AM	#4
Akagis_White_Comet Comealong busts your nuts Join Date: Jan 2009 Location: Columbus, OH Posts: 29 Rep Power: 0	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

01-01-2010, 07:02 PM	#5
Black91n/a Rotary Fan in Training Join Date: Mar 2009 Posts: 39 Rep Power: 0	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.