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

need RX7 · 05-31-2009, 08:57 PM

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*** · 06-01-2009, 12:25 AM

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 · 06-01-2009, 01:34 AM

This guy better include the crossmember with the trans, I'd really like to avoid dropping $75 on one

. I guess I could always get a used one...

Max777 · 06-01-2009, 02:37 AM

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! · 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.

05-31-2009, 08:57 PM	#1
need RX7 Clean S4 Nutswinger Join Date: Mar 2008 Location: Sterling Heights, MI iTrader: (0) Posts: 485 Rep Power: 17	S5 n/a transmission into S4 n/a, which crossmember to use? 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? __________________ -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, 12:25 AM	#2
*TitaniumTT* Test Whore - Admin Join Date: Mar 2008 Location: Right Behind you son iTrader: (4) Posts: 4,581 Rep Power: 10	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 __________________ -The Angry Stig- DGRR 2009, 2011, 2012 & 2013 - Best FC DEALS GAP!! WOOHOOOO!!!!! 2015 Audi S4 - Samantha - Zero Brap S4 2004 RX8 - Jocelyn - 196rwhp, 19mpg fuel to noise converter 2000 Jeep Cherokee Sport - Wifey mobile - Now with 2.5" OME lift and 30" BFG AT KO's! So it begins 1998 Jeep Cherokee - 5 spd, 4" lift, 33" BFG's - Rotary Tow Vehicle 1988 'Vert - In progress 1988 FC Coupe - Gretchen -The attention whore BEAST! I'm a sick individual, what's wrong with you? I'm pure Evil I'm still insane, in the best possible way. I think Brian's idea of romance is using lube. Your rage caused the meteor strike in Russia. The Antichrist would be proud of his minion. You win with your thread. Most everything It's a truck with a steel gate on the back. Just a statement of fact Motec M820, AIM dash, ported 13B-RE Cosmo, 6-spd trans, 4.3 Torsen, custom twin wg fully divided mani, Custom 4" split into 2x 3" exhaust, Custom HMIC, Custom custom custom custom I like to welder stuff.... No Bolt-ons allowed. Dyno'ed @ Speed1 Tuned by me - 405rwhp on WG.... WM50 cuming soon. *-Angry Motherfcker Mode ENGAGED-**

06-01-2009, 01:34 AM	#3
need RX7 Clean S4 Nutswinger Join Date: Mar 2008 Location: Sterling Heights, MI iTrader: (0) Posts: 485 Rep Power: 17	This guy better include the crossmember with the trans, I'd really like to avoid dropping $75 on one . I guess I could always get a used one... __________________ -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, 02:37 AM	#4
Max777 Pirate Join Date: Mar 2008 Location: Central IL iTrader: (5) Posts: 1,323 Rep Power: 18	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. __________________ Rotaries:They are NOT that complicated!

06-01-2009, 08:24 PM	#7
need RX7 Clean S4 Nutswinger Join Date: Mar 2008 Location: Sterling Heights, MI iTrader: (0) Posts: 485 Rep Power: 17	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	#5
Tanj! Rotary Fan in Training Join Date: Feb 2008 Location: Dallas, TX iTrader: (0) 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	#8
Akagis_White_Comet Comealong busts your nuts Join Date: Jan 2009 Location: Columbus, OH iTrader: (0) 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	#9
Black91n/a Rotary Fan in Training Join Date: Mar 2009 iTrader: (0) 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.