TechnoVersions Differential Mount

[wheee!]

My configuration in the pic above does not include the factory mount below the diff. I may “sandwich” the diff with a small pyramid bushing below to maintain driveline angle. Right now, my technoversions bushing has been scalloped out to the correct nose height as factory.
It will be a while before I can test it, but with never having driven the car prior, there is nothing to compare against!

[siteunseen]

haven't heard from Andrew in a while.  You still with us @ZCurves ?

[Zed Head]

I have the polyurethane GM mount like wheee!'s and the PU mustache bar mounts.  My experience is that it's the mustache bar mounts that transmit most of the gear whine in to the cabin.  I was able to reduce that noise dramatically by creating a small air gap at the bushing.  Typically the bushing is clamped tightly in place and that allows vibration to be transmitted.

The differentiation in usage is that wheee! and me are using the system as a mount.  Diseazd is using his as a movement snubber, or strap replacement.

[Zed Head]

Forgot to say that the clunk probably comes from the diff dropping back down on to the  stock crossmember mount after it lifts up.  So you really need a new or good quality factory mount along with the snubber, to avoid the clunk.

Many people have found that just paying the $70-80 for a new factory mount solves the clunk.  It's so hard to tell that the factory mount is no-good anymore though, that the simple fix is overlooked. 

The other, original, reason for the RT mount is that it's stronger.  Ron Tyler designed it to stop breaking the stock mount on his small-block chevy swapped 240Z.

I built mine cause I like building stuff.

[Diseazd]

1 hour ago, Zed Head said:

I have the polyurethane GM mount like wheee!'s and the PU mustache bar mounts.  My experience is that it's the mustache bar mounts that transmit most of the gear whine in to the cabin.  I was able to reduce that noise dramatically by creating a small air gap at the bushing.  Typically the bushing is clamped tightly in place and that allows vibration to be transmitted.

The differentiation in usage is that wheee! and me are using the system as a mount.  Diseazd is using his as a movement snubber, or strap replacement.

Thanks for pointing that out Zed Head. Yes, I'm using mine as a snubber only (factory mount on the bottom).....however, if you limit the movement of the diff and therefore the stress on the rubber stock mount, I would think the stock mount would probably last forever!

[Zed Head]

I'm sure it reduces the wear on the stock mount by a lot since the stretching motion is minimized.  And with less lift, a worn mount might not clunk.  When I was messing around with mine I actually had a snubber on top for a while, snugged way down.  The nose was clamped top and bottom.  I got lots of gear whine in the cabin then.

The other benefit to using the GM transmission mount on the top is that you can remove your rear suspension without the diff nose hanging.  Which barely matters of course since you can't roll the car around anyway.

[grannyknot]

8 hours ago, Matthew Abate said:

I know I am digging up a 5-year-old threat, but I can't find the answer to the question granny knot asked right before the thread died. I am speculating that trimming the conical insulator to be just short of touching the differential (as TechnoVersion mentions on their site) might be the solution to this, but I haven't seen anyone explicitly say that anywhere.

And 5 yrs later I can answer my own question and agree with the rest of the guys, I have the technoversion RT mount with poly snubber on top (touching) and a stock diff mount on the bottom,   No extra vibrations, No clunk, a very good combination.

[ZCurves]

20 hours ago, siteunseen said:

haven't heard from Andrew in a while.  You still with us @ZCurves ?

Yep, still alive - Just Lurking.  Thanks for checking on me!

[Jeff G 78]

I too use the TechnoVersion mount on my R200 race car with the black snubber and stock OE mount.  I can't comment on the NVH since it's a race car, but I will say that it is much easier to install the RT mount with the diff removed.  I did it with the diff still in the car and it was a terrible job.  There simply wasn't enough room to get it into place.  Again, since it is a race car, I wasn't worried about scratching the paint on the mount or the tunnel and I eventually got it into position, but on a street Z, I would never do it that way again.  I would remove the diff and then fit the RT mount.  I likely spent way longer than if I would have just dropped the diff in the first place.  I think I cut three tiers off the snubber, but I can't remember for sure.  It's been a few years since I did it.

[heyitsrama]

Sorry to resurrect such an old thread, but it might be better than fragmenting another discussion about the RT style mount used as a strap replacement (aka snubber) mode.

im trying to think if running the mount in this configuration is contributing to noise from the rear end entering the cabin at highway speeds. I did remove 3/4” of the rubber mount when I installed it, but I still recall having to use a jack to squish everything together when fitting the front diff mount. I was thinking maybe this is contributing to the problem.

i really like the RT style mount, there is no knocking from the diff moving around, yet still it’s a bit loud.

 

 

[Derek]

I'm running mine with in the "hang" style with no snubber and no bottom mount but tried a few variations before that. The mount transfers noise for sure but the best configuration was OEM rubber mount below with the snubber up top. I kept an air gap between the snubber and the diff though so that it only came into play during hard acceleration. 

One other thing to note. If there is any other issue in your drive train the mount will telegraph and amplify it. 

 

Derek

[madkaw]

I still get a thud unloading the drivetrain at low rpms in a higher gear . I still dance with the clutch to avoid the thud and I have the sandwich set up . Sometimes I think my r-180 moustache bar is not up to the task of 230 ft pounds and posi tract rear . I’ve about given up trying to figure it out what the noise is . 
I can drive my car hard and never hear a thud , but under certain circumstances i get a distinct thud . 
If I cruise around 40 mph in 4th gear and keep the throttle steady and push the clutch pedal in and out , it will thud every time letting the clutch out . That’s releasing the clutch swiftly . Granted - I don’t drive that way - but wonder where all that movement is 

Edited May 7, 2021 by madkaw