[Jackwabbit703]

Need your help fellas. I got a 66 mustang and it rode so rough I thought the 17 year old tires with cracks and flat spots were the cause. I got brand new tires balanced on it but it still rough and vibrates over 25 mph I would say. It is not bad as it was with old tires. What should I be looking to fixing next? Ball joints, tie rod bushings all looks okay. No cracks etc. thanks.

 

[ArizonaGT]

Put it in neutral when it starts doing that, see if it gets any better or worse. Could be u-joints, broken motor and/or transmission mount, bent and/or out-of-balance driveshaft, or a combination of several.

 

[ginpunk]

Is the vibration in your hands or on your seat?

 

[kketell]

Where are you feeling the vibration? In the steering wheel or in the seat of your pants?

Could be shocks.
Could be u-joints - This is potentially very bad. You drop the front of your driveshaft at any speed and you risk destroying your car.
Could be warn front suspension

Start by getting under the car with wheels off the ground. Try to move all of the various suspension members. If you find any play, fix it.

Try moving the u-joints by pulling on the shaft at the connection. Do this in both ranges of potential movement. If it is at all wobbly, replace the u-joints. Heck, you may want to replace them anyway, just for peace of mind.

Were the new tires balanced?

 

[[email protected]]

Brake drums/rotors, bent wheel, drive shaft, axel, washboard road, cheap tires, etc...
Stands, start, put in gear, see what is not running true.

 

[GradyStang]

When was the last time the car had a proper alignment done to it? Instead of throwing more money at it, I'd check that first as it's very cheap to do so. In fact, you can even do it yourself with the proper tools, or take it to a competent alignment shop in your area, if you have one.

 

[AZ_Ryan]

Vibration at speed is usually tires, wheels, or drive line.

You said you replaced the tires, but what wheels are on it?

 

[Jackwabbit703]

Is the vibration in your hands or on your seat?

Pretty much whole car. Steering not much.

 

[awhtx]

Were the new tires balanced?

From the original post:
"I got brand new tires balanced"

 

[Jackwabbit703]

Where are you feeling the vibration? In the steering wheel or in the seat of your pants?

Could be shocks.
Could be u-joints - This is potentially very bad. You drop the front of your driveshaft at any speed and you risk destroying your car.
Could be warn front suspension

Start by getting under the car with wheels off the ground. Try to move all of the various suspension members. If you find any play, fix it.

Try moving the u-joints by pulling on the shaft at the connection. Do this in both ranges of potential movement. If it is at all wobbly, replace the u-joints. Heck, you may want to replace them anyway, just for peace of mind.

Were the new tires balanced?

Yes new tires were balanced at the shop. I just put in all 4 new shocks. This is picture of the u joints. It looks greased up.

 

[Jackwabbit703]

Brake drums/rotors, bent wheel, drive shaft, axel, washboard road, cheap tires, etc...
Stands, start, put in gear, see what is not running true.

You mean put it on jackstands and start the car and put in gear?

 

[Jackwabbit703]

Vibration at speed is usually tires, wheels, or drive line.

You said you replaced the tires, but what wheels are on it?

I would say it’s more rough ride. I can hear dash moving etc.

 

[Jackwabbit703]

When was the last time the car had a proper alignment done to it? Instead of throwing more money at it, I'd check that first as it's very cheap to do so. In fact, you can even do it yourself with the proper tools, or take it to a competent alignment shop in your area, if you have one.

I was thinking about that. Not a shop in 30 miles radius has 66 mustang alignment program.

 

[f8266coupe]

Vibration at speed is usually tires, wheels, or drive line.

You said you replaced the tires, but what wheels are on it?

This ^

 

[AZ_Ryan]

I would say it’s more rough ride. I can hear dash moving etc.

What rims are on the car? Original?

 

[Jackwabbit703]

Put it in neutral when it starts doing that, see if it gets any better or worse. Could be u-joints, broken motor and/or transmission mount, bent and/or out-of-balance driveshaft, or a combination of several.

In midst of this issue, when I applied the brakes whole car pulled to the right. So I took off the front wheels, and found the driver side brakes are not engaging when I apply the brakes. Took the bleeder valve and pumped brakes, no fluid coming out. Broke the upper steel line trying to get it off. Need to order new steeline and brake hose and new cylinder just in case.

 

[Jackwabbit703]

What rims are on the car? Original?

Aftermarket American racing wheels, shop said rims spun well and no issues.

 

[D10E]

Put on jackstands and spin each wheel by hand. If it's showing up at 25 mph you should be able to visibly see something. look for a bent wheel, axle, or driveshaft/ujoints. Usually you'll hear the u joints before you feel them.

 

[Jackwabbit703]

This ^

Bf Goodrich 195/65/15 and 215/65/15

 

[Jackwabbit703]

Put on jackstands and spin each wheel by hand. If it's showing up at 25 mph you should be able to visibly see something. look for a bent wheel, axle, or driveshaft/ujoints. Usually you'll hear the u joints before you feel them.

I don’t think I can spin the rear wheel by hand up to 25mph. Probably need to start the car use long stick to press the gas pedal and see what happens.