Odd part near rear diff

[FlameThrower]

Ok so i had my car up on the lift today to do a general assessment of things that are going to need attention soon and i came across a few interesting things.

Im sure this cant be a Datsun thing can it??? It looks like it has hit the diff a few times.

Any idea what this does/what it is for??

[Zs-ondabrain]

Nissan used to throw those things on to counter ballance harmonic vibrations. or some crap like that. Though that one looks a little onthe tall side, compared to the others I've seen.

Dave

[Zforce]

Dealer installed anti vibration damper thingy supposed to cut noise and vibration for those who complained.

[grantf]

Wow! I have those seemingly useless blocks bolted on my car also but I have nver seen them welded together or 4 plus stacked and welded, makes me think someone was trying to eliminate a common problem the wrong way. but what do I know?

[Zed Head]

Wow! I have those seemingly useless blocks bolted on my car also but I have nver seen them welded together or 4 plus stacked and welded, makes me think someone was trying to eliminate a common problem the wrong way. but what do I know?

I have a 76 and a 78 parts car and they both have that ugly-looking thing. Zs apparently came from the factory like that, not sure what year it started. It's in the Rear Axle and Suspension section of the FSM, called a "damper plate". It must be designed to damp either vibrations or clunks, I would guess.

By the way grantf, I went to see what year car you had and your About Me says that you don't even have a car yet.

[FlameThrower]

That's why i was curious about what exactly it was because it looks like a hack job fix.

As for damping vibrations/clunks it is not doing its job because when i let off he gas then put my foot back in it there is a nasty clunk when the power comes back on, this could be a bad transmission mount though. All of the rubber bushings seemed to be in rough shape when i inspected it

[grantf]

I have a 76 and a 78 parts car and they both have that ugly-looking thing. Zs apparently came from the factory like that, not sure what year it started. It's in the Rear Axle and Suspension section of the FSM, called a "damper plate". It must be designed to damp either vibrations or clunks, I would guess.

By the way grantf, I went to see what year car you had and your About Me says that you don't even have a car yet.

I have a 78 280z, look up my older posts there are pictures of it. I will updat my profile.

here again is a pic of my "damper plate"

Edited May 13, 2010 by grantf

[grantf]

That's why i was curious about what exactly it was because it looks like a hack job fix.

As for damping vibrations/clunks it is not doing its job because when i let off he gas then put my foot back in it there is a nasty clunk when the power comes back on, this could be a bad transmission mount though. All of the rubber bushings seemed to be in rough shape when i inspected it

seems you have the same "clunk problem I do" search for "clunk" you will find much info as I have.

[texasz]

I've seen these before though never on the car, always in a pile of parts...in fact I believe I just sent one to the recycler last month.

Clunks could be U-Joints or mounts or even the diff arrester strap. Check them all.

[esprist]

I've seen these before though never on the car, always in a pile of parts...in fact I believe I just sent one to the recycler last month.

Clunks could be U-Joints or mounts or even the diff arrester strap. Check them all.

We created this so that the arrester band funtions as dumper to reduce that crunk during on-off accelarations.

http://jdm-car-parts.com/customizing/goto-band-arrived-datsun-240z-260z-280z/

[grantf]

We created this so that the arrester band funtions as dumper to reduce that crunk during on-off accelarations.

http://jdm-car-parts.com/customizing/goto-band-arrived-datsun-240z-260z-280z/

interesting, where does it attach?

[sblake01]

We talked about that a coupe years ago. It's a NVH damper (Noise-vibration-harshness). Here's the TSB:

TSB # TS75-068A, Sept 3, 1975

“Countermeasures for S30 R180 Differential Noise”

To reduce internal noise in the S30 differential a differential noise damper kit is now available as a service part. Differential noise is caused by the tooth meshing action of the ring and pinion gears, amplified by structural vibration of the vehicle body. The noise damper kit contains a 10 lb mass damper weight which attaches to the differential housing to absorb structural vibration and the necessary attachment hardware.

The kit can be also be applied on the 1970-74 S30, R180 differentials only. This kit should not be used on any 2+2 vehicle due to possible interference with the rear seat belt attachment bolts.

Kit Part Number: 99991-20000