TechnoVersions Differential Mount

[ETI4K]

17 minutes ago, madkaw said:

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 .

Not sure how yours is configured.  I get you are using the stock mount below, but are you using the same PU part as @wheee! at the top - so the diff is constrained from moving up or down, or is there an air gap above the diff and a different snubber?  I know using the same part as Mark would be redundant, but as I am planning to use the same hardware, I just want to be crystal clear.

[grannyknot]

1 hour ago, madkaw said:

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 

Same here, R/T mount with a poly snubber cut so it is just snug against the top of the R200 LSD diff, OEM rubber mount underneath, poly bushings in the R200 mustache bar, 83/ZXT  CV halfshafts and still get the dreaded clunk when I engage the clutch to shift to the next gear. It really bugs me but I don't know what to try next, I'm contemplating pulling the whole system and going with the Ford super 8.8 rear end from the 2015 Mustang.  There's a guy over on Hybridz that is offering a kit to install the 8.8 at a fraction of the cost of the TTT kit.  https://forums.hybridz.org/topic/128217-ford-super-88-irs-swap-thread-rear-brakes-too/

[texasz]

Ok, I bought a couple of these years ago from him and am just now getting around to doing some work on my Z.  I'm pulling the diff due to a leak (and likely installing a different one with a higher gear ratio).  I was not going to install this mount until re-reading this thread...now I'm seriously considering installing it.  

[heyitsrama]

2 hours ago, grannyknot said:

Same here, R/T mount with a poly snubber cut so it is just snug against the top of the R200 LSD diff, OEM rubber mount underneath, poly bushings in the R200 mustache bar, 83/ZXT  CV halfshafts and still get the dreaded clunk when I engage the clutch to shift to the next gear. It really bugs me but I don't know what to try next, I'm contemplating pulling the whole system and going with the Ford super 8.8 rear end from the 2015 Mustang.  There's a guy over on Hybridz that is offering a kit to install the 8.8 at a fraction of the cost of the TTT kit.  https://forums.hybridz.org/topic/128217-ford-super-88-irs-swap-thread-rear-brakes-too/

I feel like the 8.8 is a great package to go with if you got into the game late (like me) and can’t find a r180/r200. Honestly it’s slim pickings out now days (at least it feels that way). From that thread people are doing 900HP builds?, holy moly. That’s FAST. 
 

It’s seems hard to find a r180/200 that is an LSD, has the ratio that would work, does not need a rebuild, and is relatively affordable. 

i can’t think of a safe way to lift the car and have the drive train engaged in order to film or visually see what’s going on under the car. Maybe you can shove and old camera or a go-pro down there to see what’s going on?

Edited May 7, 2021 by heyitsrama

[AK260]

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 

You may have seen my post on the other thread with my homemade Mount - I too can get that thud if pressing on hard and changing up at peak torque.



The issue as far as I can see is simply that the mount / arrester is storing the energy and giving it back to the diff when you come off the power. This causes the diff mount insulator to connect with itself. Top part joined to the diff connects with the bottom part joined to the cross member.


I haven’t made a permanent fix for it yet, but I found that adding a bit of rubber between the diff mount insulator’s top and bottom parts makes it stop! I will probably modify a compression rod bush for this duty as they too are designed to take a lot of squashing!!

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.
 
 

If you had to use a jack to squash it, then I would be pretty sure that is your problem! Imho you definitely need a gap between the snubber and the diff.

[jonbill]

I've had the RT mount for few years and used 3 or 4 diffs over that time. The diff is squashed between the RT mount and the Nissan mount. I have no noises unloading the diff (with any of the diffs) , but on the first diff and the current one I could get the clunk on loading it. 

The one that had no clunk ever did develop a serious whine and on checking, the pinion is worn. 

My conclusion is that the clunk in my case is down to the clearance between pinion and crown wheel, and I'm happy to live with a clunk occasionally if It means I'm not killing the diff! 

[Zed Head]

If you use the GM top mount then it becomes a true "mount".  Most people use it as a snubber, basically a better strap, to limit the distance the nose falls back after power is let off.  If you cut the snubber too close to the diff nose then you can get diff whine in the cabin when the nose lifts up and touches the snubber, just like the typical urethane bushing problems.

The top mount lets you remove the control arm clamps without dropping the diff too.  Handy.

https://www.technoversions.com/DiffMount.html

[grannyknot]

6 hours ago, AK260 said:

I haven’t made a permanent fix for it yet, but I found that adding a bit of rubber between the diff mount insulator’s top and bottom parts makes it stop! I will probably modify a compression rod bush for this duty as they too are designed to take a lot of squashing!!

Any chance you post a pic of that setup? At this point I'll try anything.

Thanks

[madkaw]

23 hours ago, ETI4K said:

Not sure how yours is configured.  I get you are using the stock mount below, but are you using the same PU part as @wheee! at the top - so the diff is constrained from moving up or down, or is there an air gap above the diff and a different snubber?  I know using the same part as Mark would be redundant, but as I am planning to use the same hardware, I just want to be crystal clear.

Don’t remember leaving any gap - I wanted it clamped down .

[heyitsrama]

I shaved mine down to have a small gap. the total length of the snub bushing was ~29mm, if you were doing it yourself you might be able to leave the length longer, say ~31mm.

I noticed less noise from the rear end at highway speeds, 65-75mph. I did not notice any clunking sounds yet, but if i need to reduce the gap, i think fitting a rubber bushing between the poly mount and the metal would be the way to go.

I tried cutting it down to ~36mm length and 32mm length and it was still a squish fit.

It was easy to remove the bushing from the front of the diff, just had to loosen the front diff mount and lower it on a jack. You might have to pull down on the diff to fully get it out.

 

 

Edited May 9, 2021 by heyitsrama

[JagoBlitz]

Hi,

if the top mount PU solution from Energy Suspension causes increased NVH, would it be possible to use a GM-OEM-replacement?
Or would the rubber be too weak?