Hi guys,

I really hate having to ask but this one's got me stumped.

I've got a 65 coupe, 289, C4, tri-y headers, dual exhaust, edlebrock intake and 4 barrel carb. I recently had the engine rebuilt and just put it back in last weekend, with the new headers and dual exhuast (It was previously a 2v single exhaust 289).

Anyhow, a while back I also lowered it all round (1" blocks at the back) and up front I redrilled the A-arm mounting holes as per Shelby's lowering template to drop it down about an inch.

http://www.thecarsource.com/shelby/r.../lowering.html

I had the car aligned and it's been fine until this week with the new engine.

Now that the new motor is in, I started to notice that I'm getting some excessive front tire squealing. It gets exponentially louder under acceleration and at higher speed.

I took it back to the front end shop and had it checked out again and the guy showed me on the computer alignment screen that it hadn't changed. It was all exactly as he'd aligned it the first time - all within the exact range that it was supposed to be.

Thing is that I'm getting inner tire wear on the front passenger side tire, so he said he could adjust the toe a little to see if that would help the situation. So he adjusted it to as close as he could from -0.03 to +0.25 (apparently 0.23 is perfect).

Now it should be aligned better than before, but still I'm getting this screeching from the front tires.

I checked and saw that the front cross member was actually hitting the sump, so I just today went and replaced the engine mounts to rule out any interference with the motor pushing on the cross member. Now there's 1/2 inch clearance or so.

However, the problem still exists with the front end squealing. Thing is that it hasn't done this ever before, and it's the same motor (just rebuilt). The only other thing is that I ripped out the factory a/c and all it's bits and pieces because it wasn't working.

Apart from that the car is exactly as it was a couple of weeks ago save for the headers and dual exhaust, yet it squeals like a pig. The only mod to the front end was to lower the ram for the header clearance on the driver's side, using a lowering bracket which I'm sure you know how it works.

I notice that when I turn the wheel right when driving the front driver's side tire stops squealing and then when i turn left the passenger side stops squealing. However when driving straight, both wheels squeal as if there is too much toe one way or the other.

I'm completely stumped.

Any suggestions?

Thanks a bunch,

Jason

 

screw all the hard work and guessing.

Get 2 jack stands and jack the front of the car up from box frame area behind the front wheels. use one jack stand per side so the car isnt tilted left or right but both front wheels are off the ground.

Can you turn them by hand?

Hit the brakes and then let off...can you still turn them?

turn full right and test if they spin do the same to the left.

now look at the inside edge of the tire wall are there any rub marks?

look at all the related components....

The only problem is the suspension is not loaded and may act differently and not rub at all. you might try getting some friends out and going to a parking lot. put the car in neutral and have them push it then slowly crank right to full lock. push effort should increase but they should still be able to move it. do the same to the left.

Thats how I would start.

-Gun

 

Thanks for your reply Gun.

It doesn't appear to be a brake related problem or the tires rubbing anywhere. I had it up on stands last night like you described and there's full range of movement both in the steering and the wheels may be turned by hand.

It sounds just like when you take a corner too fast and the tires squeal. That's the exact sound but it's constant when the car is moving more than say 15 mph and gets increasingly louder with acceleration and speed. As soon as I gas it, it sounds like I'm peeling out but it's coming from the front tires. Last time I checked it was a rear wheel drive. =)

Obviously you don't have the issue with yours - can you tell me your front end specs? What's your toe adjusted to?

Thanks,

Jason

 

I was really hoping something would be dragging on them.

I dont remember the alignment numbers.

I think the issue is something more obvious than the toe or other alignment numbers being out a few fractions of a degree. maybe they are off a whole bunch but the guy sounds like he knows what he is doing....maybe not??

and it worked great after you did the shelby drop or has it never worked with the shelby drop?

-Gun

 

Thanks for your quick reply Gun.

He does sound like he knows his stuff. He's the only one at the alignment shop who actually knows how to align early model mustangs. Nobody else has a clue. I took it to 3 other shops in town and they wouldn't even touch it.

He seemed to think that something must be changing when the car was under acceleration as according to the machine the car is perfectly aligned when stationary.

He thought maybe it was the engine sump pushing on the cross member when under load, and causing some change in the front end - hence me replacing the engine mounts which has given the proper clearance - so I think I can safely rule out that's not the issue.

I keep reading that the machine specs aren't quite right and that people opt for more/less toe, camber, etc.

I did the Shelby drop about 2 years ago and never had the problem with the squeal. It's just been since I put the motor back in - but it's all the same stuff, so that's why I'm baffled.

Of course it could simply be a problem that occurred AFTER I put it in, but I just don't know what it might be.

 

Wheel bearings?

 

so what if you made a large continuous 15 mph circle in a parking lot?

What if you had a small video camera and attached it to a stick and had a buddy hang it out the passenger window and hold it next to the wheel and then do the same on the other side after making a right and left circle?

what if someone stood outside the car and you made this same circle?

and the car tracks and stops straight?

-Gun

 

I had this same type of problem a few years ago. The problem was stupid simple, but hard to find. After a long time searching and many (new) parts replaced, it turned out to be the upper control arm nut that holds the cross shaft in had stripped out and was letting one control arm flop around. It was hard to see because there is not enough room for the nut to fall out, so on inspection it was still there, but it wouldnt hold the arm in place. It didnt show itself on 2 alignments either because being stationary and with the full car weight on it it didnt move until the car was moving.

 

Do a search for Daze posts. He has the recommended front end alignment specifications for after doing the shelby drop. It is different than stock alignment.

 

2$ says it is the lower control arm bushings