Tracking Down The Clunk - Worn Lower Diff Mount?

[Mark Maras]

1 hour ago, Zedyone_kenobi said:

Hardware... I am going to be cutting up a heater hose this weekend!! 

 

That was brilliant... Now I wonder if their s a way to inject some hard curing silicone to accomplish the same thing. Some type of rubber epoxy maybe.  Very nice!!

 

 Silicone rubber. Versimold is heat set. Sugru is air? dry. They're both about the consistency of clay. I don't know the hardness of either one but Versimold is the most economical of the two. Has anyone tried the pourable Flex- Seal?

[Zedyone_kenobi]

just realized autocorrect changed Hardway to Hardware... sorry bud!

[Hardway]

No worries Zedy!  I think heater hose is the way to go.  Since the rubber serves as a cushioned barrier between the two plates, I would be afraid that an inject-able silicon would just crack or split.  The Flex Seal stuff might be an option but its compression strength is unknown.  Heater hose is pretty durable, cheap, and readily available.  If someone does try one of the alternatives we will be very interested to hear about your results.

[Mark Maras]

 I was thinking about using Versimold to fill the voids that remain when using the squished heater hose.

[Zed Head]

One thing that I found when I was experimenting with removing the clunk was that some solutions caused more diff noise in the cabin.  The clunk was gone but gear warble took its place.  Beware.

[nickg]

Yep sounds like we figured this one out. But for those of you searching the forum for "clunk".. I had a rear-end clunk once on my 76' 280z, and it turned out to be the u-joint on the passenger side half shaft. I swapped the CV shafts out and no more clunking. So, who ever suggested putting the car up in the air and rotating the wheel to find slack, yeah I'm agreeing with them. I would have caught that immediately.

[Namerow]

12 hours ago, Zed Head said:

One thing that I found when I was experimenting with removing the clunk was that some solutions caused more diff noise in the cabin.  The clunk was gone but gear warble took its place.  Beware.

The designs of the front insulator and the mustache bar bushings were tuned to isolate the chassis from the gear and drivetrain noise/vibration 'collected' by the diff casing.  It will be interesting to see whether stuffing the front insulator's cavity with heater hose really does have an adverse effect in the form of gear howl getting into the cabin.  Let us know what you discover.  If a problem does set up, you might be able substitute something softer than heater hose that would be better able to meet the dual requirements of noise isolation and clunk elimination.