Best tire size for a 77 Newport?

[Pclancy]

Hi folks,

I'm the guy who purchased the Canadian Newport. It's a beautiful car. I am about 1/2 way home now.

I have a question:


The car pulls ever so slightly to the left at 60-70 mph. There is also a very small vibration at those speeds. The wheels have been just balanced and the alignment just checked/adjusted. At other speeds, she tracks pretty straight and does not vibrate.

The tires are new, but the car sat for about the last year on them. The last mechanic who looked at this said the problem was probably flat spots on the tires which would work themselves out or not. I have just driven 1,000 plus miles and the problem continues.

That mechanic said if the problem continued the best solution was new tires.

 

[Pclancy]

Hi folks,

I'm the guy who purchased the Canadian Newport. It's a beautiful car. I am about 1/2 way home now.

I have a question:


The car pulls ever so slightly to the left at 60-70 mph. There is also a very small vibration at those speeds. The wheels have been just balanced and the alignment just checked/adjusted. At other speeds, she tracks pretty straight and does not vibrate.

The tires are new, but the car sat for about the last year on them. The last mechanic who looked at this said the problem was probably flat spots on the tires which would work themselves out or not. I have just driven 1,000 plus miles and the problem continues.

That mechanic said if the problem continued the best solution was new tires.

The tires I have now are Hankook H7-14 size p225/75r15.

What do you think?

If the problem is the tires, what size type tires do you recommend. The wheels are original.

Thanks

 

[twostick]

I run 235/70's on our 65 wagon and on the front of our 66.

Years ago when I had a 76 Newport Custom as a DD I ran 235/75's.

I wouldn't run less than a 235.

Assuming correct tire pressures, make sure you don't have a front caliper dragging slightly. That can make it pull and and it will cause a vibration altho my experience with a hung caliper is that once it gets the rotor hot, it shakes the car like a dog crapping razorblades. After the next long run, check the front hubs for temp difference. If the left is hotter than the right you have a brake or bearing problem. If they are equal you're back to alignment or tires.

Check the U-joints for wear. That could be the source of your vibration.

Has it done this from the get go or did it develop enroute?

Kevin

 

[300rag]

My Monaco wagon runs Hankook H724 in a 235/75-15.

 

[monaco75]

235 75s here as well. Best look for a formal IMO.

 

[75LandYacht]

Congrats on your final journey with your new toy.. On my 75 NYB I run 235/75/15 Cooper trendsetter SE's. She rides like a comfortable couch down the highway.

Even though on alignment was recently done I would check all the front and components, upper lower ball joint's, tire rods, Pitman and idler arm. If any of those are worn then you're going to feel Road vibration regardless of tires or balance.

Do you feel the vibration in the steering wheel or the seat? If in the steering wheel the vibrations upfront. If in the seat and it's in the rear, such as driveshaft or wheel balance.

 

[cantflip]

I hate to argue with another tech... wait, no I don't. The flat spot issue shouldn't last to long if it's from sitting... if the tire is making the pull... swap the fronts with each other and see if the pull changes sides (he should have done this). If the pull follows the tire, you need only replace that one. A radial pull is considered the first indicator of a failed inner structure in a tire and a blowout possibility. If the front doesn't change the pull the rears should be swapped to make sure it isn't a tire.
You have some good advice on the brakes here, but if it is a caliper slide that needs cleaned and lubed... that could be done quickly and easily while playing with the tires.

A decent mechanic would take the time to answer these questions, but they are harder to find than most realize... especially when it comes to an unfamiliar car. Don't trust that the wheel balance was done correctly also... and if anyone pumped moisture into the tire because they were too lazy to drain their compressor... you will fight balance until someone finally figures it out.
Balance won't cause a pull though...

 

[Pclancy]

I run 235/70's on our 65 wagon and on the front of our 66.

Years ago when I had a 76 Newport Custom as a DD I ran 235/75's.

I wouldn't run less than a 235.

Assuming correct tire pressures, make sure you don't have a front caliper dragging slightly. That can make it pull and and it will cause a vibration altho my experience with a hung caliper is that once it gets the rotor hot, it shakes the car like a dog crapping razorblades. After the next long run, check the front hubs for temp difference. If the left is hotter than the right you have a brake or bearing problem. If they are equal you're back to alignment or tires.

Check the U-joints for wear. That could be the source of your vibration.

Has it done this from the get go or did it develop enroute?

Kevin

It did this from the get go. The problem is not new, and when the problem continued after wheel balancing and and an alignment, the Canadian mechanic said to get new tires. The u joints are new. The wheel bearings were also checked before the trip. I will check the hubs for temp difference as you suggest. Thanks.

 

[Pclancy]

Congrats on your final journey with your new toy.. On my 75 NYB I run 235/75/15 Cooper trendsetter SE's. She rides like a comfortable couch down the highway.

Even though on alignment was recently done I would check all the front and components, upper lower ball joint's, tire rods, Pitman and idler arm. If any of those are worn then you're going to feel Road vibration regardless of tires or balance.

Do you feel the vibration in the steering wheel or the seat? If in the steering wheel the vibrations upfront. If in the seat and it's in the rear, such as driveshaft or wheel balance.

Vibration is more in the steering wheel. Thanks for the advice.

 

[Pclancy]

I hate to argue with another tech... wait, no I don't. The flat spot issue shouldn't last to long if it's from sitting... if the tire is making the pull... swap the fronts with each other and see if the pull changes sides (he should have done this). If the pull follows the tire, you need only replace that one. A radial pull is considered the first indicator of a failed inner structure in a tire and a blowout possibility. If the front doesn't change the pull the rears should be swapped to make sure it isn't a tire.
You have some good advice on the brakes here, but if it is a caliper slide that needs cleaned and lubed... that could be done quickly and easily while playing with the tires.

A decent mechanic would take the time to answer these questions, but they are harder to find than most realize... especially when it comes to an unfamiliar car. Don't trust that the wheel balance was done correctly also... and if anyone pumped moisture into the tire because they were too lazy to drain their compressor... you will fight balance until someone finally figures it out.
Balance won't cause a pull though...

Great advice. I will have another mechanic check it out and wrap the tires as you suggest.

 

[1978 NYB]

First things first....

Did you check the actual tire manufactured date on the tires yourself?

If you put on new tires....I have 2 Formal's both have P235/75-15's.

How old are your tires

 

[Pclancy]

I hate to argue with another tech... wait, no I don't. The flat spot issue shouldn't last to long if it's from sitting... if the tire is making the pull... swap the fronts with each other and see if the pull changes sides (he should have done this). If the pull follows the tire, you need only replace that one. A radial pull is considered the first indicator of a failed inner structure in a tire and a blowout possibility. If the front doesn't change the pull the rears should be swapped to make sure it isn't a tire.
You have some good advice on the brakes here, but if it is a caliper slide that needs cleaned and lubed... that could be done quickly and easily while playing with the tires.

A decent mechanic would take the time to answer these questions, but they are harder to find than most realize... especially when it comes to an unfamiliar car. Don't trust that the wheel balance was done correctly also... and if anyone pumped moisture into the tire because they were too lazy to drain their compressor... you will fight balance until someone finally figures it out.
Balance won't cause a pull though...

I found a competent tire/auto repair shop on the road, and the problem was fixed by switching the tires around in enough combinations (left/right front/rear, etc) until there was no pulling to either side. The tires were also rebalanced. Took about 3 hours, but problem fixed! Thanks to all for the advice.