Refurbing rubber isolation mounts for a subframe brace...ideas needed!

turbolife

Member
:
2003.5 Mazdaspeed Protege
Ok guys, I recently won a Carbing subframe brace for my NA Miata.

This brace bolts to the subframe near the rear mounting points of the LCAs and also has a bracket that ties into the two lower fasteners on the transmission bellhousing (image below).

f2ed_1.JPG


As you can see, there are two rubber vibration isolators that go between the tranny bracket and the brace itself. These are ripped.

Researching cylindrical vibration mounts, I cannot find any with a high enough rating when dealing with shear forces to keep them from tearing again.

pic_ad2.gif


So, what I need, are ideas on how to rebuild this.

I don't want anything 100% solid as it will transmit a ton of NVH into the cabin.

My current thought is something like this....

Take a threaded rod and some sway bar end link bushings and set it up like this.

End link bushings -

EndLinks8.jpg



nut---lock washer---1" washer---bushing---bracket to bellhousing---bushing (or bushings, depending on how much space is needed to fill)---bracket on brace---bushing---1" washer---lock washer---nut

So, there would be a threaded rod (sized slightly smaller then the ID of the holes in the bracket) with the above sequence of washers, bushings, etc bolted to it.

I would imagine this would be much stiffer then the ****ty rubber snubbers that ripped off of this brace.

Would it be too stiff/direct of a connection though and vibrate like a *****?

What are your thoughts guys? Positive and negative appreciated, as is any other good ideas!!
 
What purpose does this serve to support the transmission? The entire drive line is already supported and tied together quite well through the original design.

To minimize movement of the engine/transmission (and prevent sheer forces on those bushings, upgrade the engine mounts. Mazda performance mounts reduce engine movement considerably over the stockers. Furthermore, depending on the age of your current engine mounts, one or both may be separated...not uncommon. Such will induce quite a bit of movement in the forward drive train.
 
What purpose does this serve to support the transmission? The entire drive line is already supported and tied together quite well through the original design.

Haven't really thought in depth about it.

I have a '91, w/no factory bracing. I was going to buy the 949 front and rear subframe bracing, but this came up for a good price.


To minimize movement of the engine/transmission (and prevent sheer forces on those bushings, upgrade the engine mounts. Mazda performance mounts reduce engine movement considerably over the stockers. Furthermore, depending on the age of your current engine mounts, one or both may be separated...not uncommon. Such will induce quite a bit of movement in the forward drive train.

Good suggestion. I have a set of Mazda Competition Mounts already.
 

New Threads and Articles

Back