Screech sound on heavy acceleration

[Stallion]

Okay, I was driving out tonight and all was well. No problems, even when I put my foot in it. And then all of a sudden, I really put my foot in it (nothing that I don't always do) and accelerated and I heard this loud squeal. It sounded like it was coming from the rear of the Vette, but I don't really know for sure.

What could this be? It only happened when I accelerated real hard. If I don't do that, it's fine.

What could it be? What do you think the problem is??

Thanks.

Stallion

 

[brusso]

Okay, I was driving out tonight and all was well. No problems, even when I put my foot in it. And then all of a sudden, I really put my foot in it (nothing that I don't always do) and accelerated and I heard this loud squeal.
Stallion

Was it dark? In other words, did you have the head lights on? "I was driving out tonight "

I know that you said that it sounded like it was coming from the rear but sound can travel in strange ways, in a car. It may be as simple as the alt belt. If I remember correctly, you recently asked about replacing the p/s belt? If so, you may just want to recheck the alt belt, or all belts for that matter.

 

[Stallion]

No it wasn't dark. And I just checked the belts and they seem alright. What else could it be??

Thanks.

 

[brusso]

Well, ......... I never heard a squeal out of the rea end that I didn't like.

But seriously, I couldn't even guess with out waisting your time but I'll be watching.

 

[Stallion]

Ehhh, anybody have any other ideas?

 

[FX GS]

Was it accompanied by any wisps of smoke eminating from your rear tires?

 

[Stallion]

No. But seriously, what could it be?

 

[JohnZ]

If it's just a screeching sound and isn't accompanied by a vibration or shudder, chances are it's a belt that isn't tensioned enough. At the center of a straight span of belt, it should deflect about 3/8" or so with a 10# load at that point.

 

[sherry_ridgeway]

hey stallion
What kind of screetch was it exactly?..did it sound like metal on metal? rubber slipping?, gears grinding?...also did the car react any differently than normal?
IE pulling to one side or another...did you look underneath to make sure nothings broken?...
sherry

 

[Mart]

It's usually a good indication of a bad set of traction units (Tires) if they start to smoke you know they are the problem.

Really good traction units don't make that noise they they sound like this "Whoa Sh--, that was cool"

Mart

 

[Stallion]

If it's just a screeching sound and isn't accompanied by a vibration or shudder, chances are it's a belt that isn't tensioned enough. At the center of a straight span of belt, it should deflect about 3/8" or so with a 10# load at that point.

But, John, I checked the belts and they seem to be alright. I'll give them another check. The sound doesn't sound like it's coming from the engine bay, though. It does sound like the rear.

 

[Mart]

Does it almost sound like it might be coming from inside the car?

 

[Stallion]

Hmmm, yeah you could say that. Why?

Okay, I just had her out again. The "sound" (more of a rubbing sound, not really a screech) isn't constant. When I accelerate hard it makes the sound a couple of times, but most of the time it is not constant.

It only happens in 1st and 2nd gear (maybe because 3rd and 4th have very little acceleration..?).

Any other ideas?

 

[Stallion]

And by the way, it's not the belts. I checked them and they are at a fine tension.

 

[Mart]

I had a similar problem with my 86 last year, I never found the source o fthe noise, I was thinking it might be the fuel pump, even the rear speakers.


It would make the noise very inconsistantly though. I just changed the fuel pump so we'll see if it makes that sound again.

 

[Stallion]

Maybe this is connected to this problem:
My tranmission just picked up this new leak. It's leaking now like there is no tomorrow. I'm going to change the fluid to make sure there are not metal shards in there.

If that doesn't work, I'll go to the u-joints.

 

[68Roadster]

TR,
How does your clutch feel after the change?? Does it feel like it is adjusted properly?? Does the sound only happen under acceleration or will it continue if you let off the gas? How is the throwout bearing? I'm supposin' you used a new one....
Is the driveshaft rubbing something? I know you had some trouble getting the crossmember brackets and all back in there (previous post), is everything clear of each other?
Keep us informed.

 

[Stallion]

The clutch feels fine. I'll get under her and see if something is rubbing, but it's not like this is the first time I've driven her after the clutch job. It has been many, many miles since then.

 

[wishuwerehere82]

Uh-oh,

Is it leaking in the front, or the back? I know you're not looking forward to pulling that tranny again. I hope it's the back so you don't have to do any more than put in a new rear seal.

 

[JohnZ]

If the "rubbing" you hear/feel only happens under acceleration in 1st and 2nd gear, a dime will get you a donut that it's deteriorated rubber bushings where the steel support bracket on the front of the differential bolts up to the center of the frame crossmember (very common problem). When they deteriorate, they allow the nose of the diff (and the rear prop shaft U-joint) to move upwards, and the rotating U-joint can scrape on the top of the tunnel in the floor pan under acceleration. If that's the case, use the correct OEM rubber bushings with the correct molded-in steel sleeve to replace them, NOT the "hot-rod" poly bushings; the poly bushings aren't even close to the correct thickness, require a stack of Bubba washers to properly position the bracket, don't have the correct alignment sleeve, and all they do is transmit noise and vibration into the frame (and into the body).

Where is the transmission leaking from?