Hope someone can square me away on this one…

I’ve been trying to figure out my Diff situation, it seems I’m getting the rumbling sound during turns so many have posted about. In reading some of the post I’ve actually become worried about the “Locked diff” scenario. So… Being new to the Corvette world but using my extensive knowledge of racing (ummm… RC racing that is, yes I’m ducking for cover now), I want to see if I understand how the diff works.

Anyhow, this is how I tested to see if my diff is actually locked up: I jacked the car, took it out of gear, released the E-brake, and spun one rear wheel while watching the other. Both wheels spun in the same direction with little force applied. That's normal… Right??? Then, I lowered the car placing one wheel on wood blocks for tension and spun the free wheel… It took a little more force but it had smooth rotation in both direction, no grinding noise or serious binding. I repeated the process on the other side with the same result. If I was unable to turn the free wheel while the other wheel was under tension that would show a possibly locked diff… Correct???

I’m hoping I just need a simple fluid change and not something more major. The car is still under GM warranty so cost is no problem; I just hate having my car laid up.

Any ideas, does my troubleshoot make sense or did I blow it. Any and all help greatly appreciated!!!

TIA & Mahalo

Mark

 

Best way to check the posi is to use a tourqe wrench and do the thing called breaking load, you can find the specs somwhere online usually around 150 lbs to break the load on the posi by jamming on wheel and hooking up a tourqe wrench to the other and find out what pressure it takes to break it.. In your case the noise around corners is probbly a wheel bearing, usually a locked posi will squeek the tires going around corners since its acting like a spool that lockes both axels, when one is working and you dnt have posi addative it will chatter. wheel bearings will make a whirling, howling noise around corners, so check your wheel bearings.

 

Thanks for the good gouge!!!

I ended up changing the diff fluid anyway (Royal Purp stuff) & did the old slow "figure 8" action. The sound went away, go figure I'm going to check out the wheel bearings anyway just to make sure. I figure it'll be a good learning experience and help me understand the mechanics of this car a lot better.

Big Mahalo!!!

Mark