ryanleiker

iTrader: (2)

I just put in a 9" with Strange s-trac and caltracs in my Nova.

At highway speeds, cruising, under no-load, I have a light "singing" sound coming from the back of my car, somewhere in the chassis. Starts becoming noticeable at 55-60 mph and gets a little louder and increases pitch with higher speeds.

I think it might be normal rear end noise, but I want to try to diagnose it... and make it go away.

My thoughts:

The solid front eye bushings from the Caltracs are transmitting noise from the rear end.

The solid mounting between the leaf spring perch on the axle tubes and the shock plate connecting to the caltracs is transmitting more noise as well.

The bolt and nut from the front spring eye is in contact with the frame rail when everything is snugged up which could be creating too much contact and transmitting vibrations.

Will the Caltracs become less efficient on the street if I put a poly pad in the leaf spring perch?

Should I reduce the caltracs preload?

Is this normal "race car" noise and I'm just an amateur with fast cars?

Is this the S-trac making it's normal "helical gear" operational noise?

Razor

"singing" or whine?

I had solid front bushing's in my multi-leafs prior to the current Cal tracs and did not notice any noise from them.

ryanleiker

iTrader: (2)

It's more like a singing.
It doesn't sound like a bearing whine.
And it only happens a zero load cruising. Not even really at coasting, only when the engine is maintaining speed or letting the car slow a little bit.

Are you running "metal to metal" between the spring perch-leaf spring-Caltacs mount plate?
Would it be a bad investment to put a poly isolator between the leaf spring and these two metal surfaces?

ryanleiker

iTrader: (2)

Note: I'm still breaking in my new gears and I've only got about 250 miles on them. I was told I need to go 500 before things really settle in.
It's possible on tonight's drive the noise isn't as prevalent, but it's still there.

jmm98LS1

iTrader: (28)

What brand ring/pinion? Some gears (like the richmonds that I have) are impossible to make completely quiet, no matter how perfect the setup is.

ryanleiker

iTrader: (2)

I think they're Yukon, but they might be Richmond, I'll have to double check.