Okay, so this car just gets better and better. I'm still trying to figure out the shake problem at low RPMs (high speeds) and when coming to a stop, and maybe this plays into it. I noticed this after first getting it, but it went away and has since come and gone. When I turn a corner tight going really slow, like 5 mph, I get knock coming from the back of the car and slight grinding sound. Let's have it guys. Differential??? Drive shaft connections? The devil?!?!!?!? Lol, thanks!

Justin

 

i am kind of confused, this is posted in the engine section and you seem to be describing a suspension chassis issue.,

have you checked the simple things like brake pad wear, rotors, loose caliper bolts and even loose lug nuts.

kinda hard from that description, any chance of getting it on video

 

Yeah, I probably put this in the wrong section, but it still might involve the driveshaft, etc. So I'm not sure which forum would be appropriate for that. All things aside,....

It's really intermittent, so I doubt I could get it on video--I'll try though. I'll run around and check all the rotors, pads, etc, but I'm pretty stumped on it. As I said, it only happens when I turn really hard (all the way to the left or right) and the car is going slow. It's a pretty harsh grind, so I can't imagine it's playing all that nice with my car mechanically.

 

limited slips diffs that are low on fluid or more importantly the additive will cause a chatter on a turn.

 

That's what I heard a while ago. It only seems to do it after a very long trip (over 150 miles). These don't go out eventually, do they? And if I should just replace the fluid, which kind should I use?

 

Like he said probably a chassis, suspension or steering problem and usually with the differential youll get a little vibration. Well anyway they do go out sometimes and also there easy to check i think depending on the year they have a filler hole that you would usually use a needle noses container to seep into to fill to the bottome of that seep hole. This is an easy fix or to just check to rule it out. But if the fluid is fine id bet its not the differential its the suspension or steering. Also the one thing that would make me believe its your differential is if it doesnt do it at first and then it starts to after a while of driving meaning your differential is warming up and your just probably low well good luck and make sure you check it before the next long drive or any driving for that matter if you have the time.

 

Lol, okay wait. I'm trying to understand what you are telling me to do. How do I check the differential fluid to see if it is low?

 

Jack up the car...as level as possible. On the side of the diff is a square drive plug. Pull that plug and insert a finger....the oil should be just below the hole. When filling these things you pump oil in until it flows back out and then insert the plug.

Your issue could also be wheel bearings...check all four, even if ythe noise seems to come from the back.

 

Alright, thanks! I'll give it a check and look at the brakes/bearings/steering if that comes up with nothing.

 

Okay, so...I'm guessing I have to pull the backing plate off to drain the oil, huh? That means a new gasket... Any particular favorites? :'(

 

Any gasket will work, I like felpro w/a skim coat on black silicon on both sides. Make sure you use the GM anti-slip additive or you'll be back in the same boat again.

 

Okay, sounds good. Besides the additive, what kind of oil do you suggest?

 

4ozs of the additive and any conventional GL-5 rated 80w-90 gear oil. Synthetics aren't recommended unless you have a 98+ rear/diff. I use either pennzoil or valvoline w/o any issues every 30k miles.
SB:#76-02-02A
REVISION: 09/25/98

 

Thanks buddy! Helps a lot!