[urq] transmission and differential mount interchangability

[Ado Sigal]

Rich Letsinger wrote:

>I did the opposite and used the rear mounts for both the transmission and 
>the differential. You're right about the rigidity of the rubber being higher 
>on the rear ones.
> Rich
>
>  
>
I've used SQ mounts (green markings) front and rear, which required prop 
realignment and reduced preload height by 2mm, and prop support spacers 
from 6 to 2mm. Any change in mount density evidently requires prop 
alignment check, but has limited effect on units movement, which is 
controlled by the hut shaped washer at the bottom of the mount. In my 
case the space between the mount edge and the limiting washed changed 
from 7  to 5mm. Not content with the movement of the units, I reduced 
the the washer - mount space to zero, by reshaping the hut washer, and 
there was a considerable improvement over the humps and bumpy road. 
Another washer was installed that pre loaded the mounts by 3mm, aligned 
the prop, and any vibration from the tranny and diff disappears 
completely and the car feels much tighter overall. Must say that with 
pre loaded mounts any discrepancy in alignment actually pronounced the 
vibration, so the alignment in both planes has to be perfect for this 
mod to work. The zero preload was much more forgiving. The only movement 
one can notice now comes from rubber central prop support, which I 
intend to limit via foam ring. If any one of you wants to try this mod, 
let me know.

Regards,

Ado