I bought a new S5 n/a trany mount brace from Atkins Rotary - best price. I had mistakenly bought a S4 n/a unit earlier. The attached photos clearly show the different in width of the bushing mounting points - the S5 n/a unit is in the rear. The Y-block itself is also different, wider for the S4 and narrower for the S5. This also means of course than the case n/a trany case is different between the S4 and S5 models. But they use the same shape/size mount bushings, go figure. I went with the stiffer Mazda Competition bushings.

As far as stiffening the mount bushing itself in the cross member, yes 3M window sealer is great for filling the voids noted in the last picture. It is a 55 durometer (shore A scale) polyurethane that will help to firm things up. A friend of mine has also used this method to firm up engine mount and suspension mount bushings in his Evo. I have used it in other cars to firm up engine mount and sub-frame bushings. I have talked to a couple RX7 owners that have pressed out the stock mount bushing and pressed in a polyurethane one with a front control arm which supposedly fits, although I have not tried that method.

 

Will be doing this soon. So the pics on top are with the front control arm bushing from a Fc or a different car?

 

that is a new OEM crossmember, no one has provided pics or part numbers of the bushings that have "worked".

 

Once, I just wrapped the outer rubber of center part(where it rips) in electrical tape and beat it back up into place with a socket. Bolted it back down, good to go. Several other times I've just bought the new crossmember.

 

Here.

Attachment 491277

 

Next time I'm there I'll have to see if it's under warranty and grab the number.

 

Fb715 is the part number I used. It may not work with the factory stud in the "y" bracket, as mine was broken and needed to be replaced.

 

i just bought the FB715 bushing ($7 on eBay)and im going to install that this weekend to let you guy know if it works with the "Y" bracket.

 

So I finally got around to installing the FB715 bushing (from a camaro I believe) and it does fit but you will need a press to install (duh!). And like Papio stated it does need the center spacer to be bored out with a drill bit to clear it about 1/8-/14 of an inch. Also THE RUBBER WILL MELT IF DRILL TO LONG SO POUR WATER TO KEEP THE TEMPERATURE DOWN. After a long test drive I can say this works very well as I don't have any low RPM clunking coming from my transmission anymore, I don't here or feel my front differential mount flexing as much anymore, my shifter raised in height and re-centered itself, and of course the shifts are much smoother and solid! Mind you that I have MazdaSpeed front differential competition mount as well as the pinion snubber bump stop, and a C's short throw shifter on top of that. So anyone looking to do this I would highly recommend the bushing replacement.

Sorry I couldn't take any pics of the job but its pretty straight forward

 

my bad

 

Sounds good im going to do this soon .....screw spending 80 for the whole thing

 

Tell me about it

 

Bumping a old thread . I'm going to be replacing my engine and trans mounts with solid aluminum mounts . Is the y bushing still being used once the mounts are installed . Meaning does it still compress and so on ? If so I'll order the bushing above since mine has collapsed

 

Fb715 did not work for me, any body have part numbers to try?

 

Atkins makes (and stocks) the center bushing - they sent me one to test... its perfect.

https://www.atkinsrotary.com/store/8...g-fb01-39-360-