Front spec alignment for radial Tires

[Turbinator]

Looking for specific specifications for front end alignment for radial Tires on 63 Riviera

 

 

[RivNut]

From the search feature:

 

Read the last post in this thread. Then do a search for 'positive caster' and see what Tom T. and others are doing to achieve that.

 

 

 

 

 

Edited November 5, 2017 by RivNut (see edit history)

[NTX5467]

Certainly, there are a few things which are more critical on radial tire alignment than on bias-ply or bias-belted tires . . . both of which were available when the first-gen Rivieras were still "new" or "used cars".

 

The toe-in adjustment is something of a "pre-load" adjustment to take into account the actual "rolling toe-in" of the vehicle.  How much the rubber in the suspension pivot points will compress as the tires roll down the pavement, for example.  End result should be a "zero" rolling toe, as close as possible, generally, but a slight amount of "toe-in" can help stabilize the vehicle.

 

In general, I don't recall any magazine articles on the best alignment setting for radial tires, back then.  There was agreement that Camber was less critical with radials due to the greater flexibility in the sidewall area.  Plus that toe-in adjustments might be best if set toward the minimum of the factory specs.

 

Reason for the "min-spec" setting?  The radials have less rolling resistance than bias or bias-belted tires, generally.  Therefore, less pre-load is needed in the settings to achieve the zero-toe-in rolling toe-in ultimate goal.

 

When GM started to use the All-Season radials in the middle 1980s, that was the start of the modern era of tire alignment, so to speak.  For some "chunkier" tread designs, the existing toe-in setting resulted in poor tread life and wear patterns.  In this "modern era" of front end alignment, that was when toe-in settings could be expressed in either "inches" of toe-in, OR "degrees" of toe-in (usually decimal numbers!).  I don't recall any other significant changes in the front suspension components, just the change in specs to account for "harder" tires and less tread compliance, compared to prior tire designs.

 

Increasing the Caster adjustment toward max can have a few affects.  One would be more forceful self-centering of the steering wheel after completion of a turn.  The other might be (especially in the non-power steering days!) increased steering effort, not a big factor in the power steering eras.  But the other thing can be that it adds more negative camber to the outside wheel in the turn, with increased positive camber to the inside wheel in the turn.  Why is this significant?  As the body leans into the turn, depending upon the particular suspension geometry, the wheel can lean in the same manner as the car body/chassis does.  The additional negative camber on the outside (greater load bearing) wheel helps brace the tire against the greater forces it now sees, by keeping the outside tire more vertical to the road surface.  Similar with the inside tire, as to keeping it more vertical to the road surface as the car body/chassis leans.  How much this helps can be dependent upon how much this sort of thing is designed-into the basic suspension geometry of the vehicle.  I  believe that a max of about 2 degrees of positive Caster is about all that can be achieved, unless the design has more built into it from the start.  In any event, more positive Caster is generally associated with greater straight-line stability as it keeps the front tires "centered" in their side-to-side turning arc.

 

In prior times, if a car could have both manual or power steering, the power steering models had alignment specs with positive camber, the manual steering model of the same vehicle would have negative Camber settings, especially on the heavier cars, for easier steering efforts.

 

In cases where "radial tire lead" happened in the middle 1970s, the Caster adjustment was used to balance that, deviating from the factory specs in the process.  Just as when highly-crowned roads existed in prior times, the front wheel with the highest Caster was the side the vehicle would "lead" toward, keeping a centered steering wheel rather than having to consciously counter-steer "up" the crown to stay "in lane".  "Cross-caster" is that spec allowance.

 

In general, to me you can look at the factory specs or you can use some basic generalities.  With radial tires, toe-in needs to be toward or at the low end of the factory spec, possibly just a tad above "zero", especially with recent-new suspension bushings.  For bias ply, use the factory specs.    Camber should be pretty much "zero", too.  Caster?  Aim toward the factory specs "preferred" setting or the upper end of the spec.

 

Then . . . to complete the situation, aim for a minimum of 28psi in the rear tires.  Back then, the "soft ride" pressure was usually 24psi, but many stated that for "highway speeds" to increase that cold pressure by 4psi, which is 28psi.  For the front, which is where the majority of the car's weight is carried (unless the car's trunk and/or rear seats are occupied, I found that an additional 2psi would balance the weight-carrying capacity of the tires with the weight each axle-end of the car carried.  So,, 30 front/28 rear.  From there, add air pressure to maintain that f/r balance.  Steering response is a little sharper and each tire should wear "flat" across, no thin spots in the middle or edges as a result, especially with bias-[ly tires.  If more weight is carried in the trunk, add at that end only.  The whole orientation is to help decrease "understeer" in turns.  Proceed at your own discretion in these areas.  It worked for me, but your results might vary.

 

NTX5467

[Turbinator]

36 minutes ago, NTX5467 said:

Certainly, there are a few things which are more critical on radial tire alignment than on bias-ply or bias-belted tires . . . both of which were available when the first-gen Rivieras were still "new" or "used cars".

 

The toe-in adjustment is something of a "pre-load" adjustment to take into account the actual "rolling toe-in" of the vehicle.  How much the rubber in the suspension pivot points will compress as the tires roll down the pavement, for example.  End result should be a "zero" rolling toe, as close as possible, generally, but a slight amount of "toe-in" can help stabilize the vehicle.

 

In general, I don't recall any magazine articles on the best alignment setting for radial tires, back then.  There was agreement that Camber was less critical with radials due to the greater flexibility in the sidewall area.  Plus that toe-in adjustments might be best if set toward the minimum of the factory specs.

 

Reason for the "min-spec" setting?  The radials have less rolling resistance than bias or bias-belted tires, generally.  Therefore, less pre-load is needed in the settings to achieve the zero-toe-in rolling toe-in ultimate goal.

 

When GM started to use the All-Season radials in the middle 1980s, that was the start of the modern era of tire alignment, so to speak.  For some "chunkier" tread designs, the existing toe-in setting resulted in poor tread life and wear patterns.  In this "modern era" of front end alignment, that was when toe-in settings could be expressed in either "inches" of toe-in, OR "degrees" of toe-in (usually decimal numbers!).  I don't recall any other significant changes in the front suspension components, just the change in specs to account for "harder" tires and less tread compliance, compared to prior tire designs.

 

Increasing the Caster adjustment toward max can have a few affects.  One would be more forceful self-centering of the steering wheel after completion of a turn.  The other might be (especially in the non-power steering days!) increased steering effort, not a big factor in the power steering eras.  But the other thing can be that it adds more negative camber to the outside wheel in the turn, with increased positive camber to the inside wheel in the turn.  Why is this significant?  As the body leans into the turn, depending upon the particular suspension geometry, the wheel can lean in the same manner as the car body/chassis does.  The additional negative camber on the outside (greater load bearing) wheel helps brace the tire against the greater forces it now sees, by keeping the outside tire more vertical to the road surface.  Similar with the inside tire, as to keeping it more vertical to the road surface as the car body/chassis leans.  How much this helps can be dependent upon how much this sort of thing is designed-into the basic suspension geometry of the vehicle.  I  believe that a max of about 2 degrees of positive Caster is about all that can be achieved, unless the design has more built into it from the start.  In any event, more positive Caster is generally associated with greater straight-line stability as it keeps the front tires "centered" in their side-to-side turning arc.

 

In prior times, if a car could have both manual or power steering, the power steering models had alignment specs with positive camber, the manual steering model of the same vehicle would have negative Camber settings, especially on the heavier cars, for easier steering efforts.

 

In cases where "radial tire lead" happened in the middle 1970s, the Caster adjustment was used to balance that, deviating from the factory specs in the process.  Just as when highly-crowned roads existed in prior times, the front wheel with the highest Caster was the side the vehicle would "lead" toward, keeping a centered steering wheel rather than having to consciously counter-steer "up" the crown to stay "in lane".  "Cross-caster" is that spec allowance.

 

In general, to me you can look at the factory specs or you can use some basic generalities.  With radial tires, toe-in needs to be toward or at the low end of the factory spec, possibly just a tad above "zero", especially with recent-new suspension bushings.  For bias ply, use the factory specs.    Camber should be pretty much "zero", too.  Caster?  Aim toward the factory specs "preferred" setting or the upper end of the spec.

 

Then . . . to complete the situation, aim for a minimum of 28psi in the rear tires.  Back then, the "soft ride" pressure was usually 24psi, but many stated that for "highway speeds" to increase that cold pressure by 4psi, which is 28psi.  For the front, which is where the majority of the car's weight is carried (unless the car's trunk and/or rear seats are occupied, I found that an additional 2psi would balance the weight-carrying capacity of the tires with the weight each axle-end of the car carried.  So,, 30 front/28 rear.  From there, add air pressure to maintain that f/r balance.  Steering response is a little sharper and each tire should wear "flat" across, no thin spots in the middle or edges as a result, especially with bias-[ly tires.  If more weight is carried in the trunk, add at that end only.  The whole orientation is to help decrease "understeer" in turns.  Proceed at your own discretion in these areas.  It worked for me, but your results might vary.

 

NTX5467

NTX5467, thanks so much for explanation of what, why, and wear regarding front end alignment of 63 Riviera running radial tires. I’ll summarize your info for my tire guy, who is a real car nut that collects Aldo Romeo cars, when I take the car in for alignment. The last set of 4 tires had plenty tread and no wear patterns but were 10 years old. I’ll take the 63 back for alignment check.

thanks again,

Red Riviera Bob

[telriv]

MANY newer cars run as much as 10*+ of positive caster. I like to get as much as possible within the design limitations as possible. I run +4* positive on my ''64 for yrs. now. Like like to be around +1/4 to -1/4 on camber. Whatever the toe, let's say 1/8th." - 1/4_ I adjust in the middle at 3/16ths. for BOTH sides. So divide that 3/16ths. in half for each wheel. The other positive effect of more positive caster is better resistance to cross winds as well as what was previously mentioned.

 

 

Tom T.

[rodneybeauchamp]

Re tyre pressure, I'm  doing an interstate trip next weekend, two other passengers but minimal luggage.

 

Have been running 35psi all round on 235/75 R15 but now think this might not be correct.

 

Is this too high, as NTX5467 mentioned 30 front and 28 rear?

 

What pressures do others run in theirs?

 

[Bloo]

2 hours ago, rodneybeauchamp said:

Have been running 35psi all round on 235/75 R15 but now think this might not be correct.

 

In the 1980s, when radial tires became popular, nearly every 60s, 70s, or 80s American car in the country (USA) had 35 pounds in the tires. That was also the maximum pressure listed on the sidewall.

 

The factory would deliver the cars with a sticker in the door advocating some ludicrous low pressure, like 24 or 26 pounds. The proud new owner would then drive from the dealership to the nearest gas station complaining about the flat tires. I or some other fellow would pump the tire pressure up to 35 pounds where it would remain through every set of tires that the car ever wore.

 

You certainly can fine tune tire performance with pressure. NTX5467 gave a very good explanation of how. If he thinks 30/28 is better on a Riviera, I am inclined to believe him.

 

You wont hurt anything with 35 though. Everyone did it.

[Turbinator]

Bloo, I’m no hot rod, nor am I a kid. The GM cars I drove in the 60’s with power steering came right back to me the minute I got behind the wheel of my 63 Riviera. I’m not saying it is bad, but a person has to pay plenty of attention to speed, braking, turning -you know driving a 63 Buick Riviera. The Riv I bought is solid and straight. Nonetheless, the feel in the Riv is much different than my 2013 Toyota Highlander, or that matter my 1997 Ford F-250 pick up.

im going to review all the good information I have and experiment with different tire pressures. I always liked my Tires at what the car specified, of course within range of the tire spec as well. I did not expect the Riv to drive any different than it did with 225/70 R 15 when I first bought the car. I put on new radials of the same size just different brand. The shocks are good and the front end tight, still I’m going to experiment with a new alignment and tire pressures in front and back. The country roads in Maryland are pretty good and well enough maintained you don’t need a Humvee to travel, but with the Riv I want to keep my speed well in check.

Thanks again, 

Red Riviera Bob

[telriv]

Bob,

 

   One of the BIGGEST improvements you can make to your STOCK '63 Riv. is to install a newer steering box with LESS turns lock-lock.  You WON'T believe the diff.  Adding to that is Bilstein shocks or at least KYB's, a bigger front sway bar, poly bushings in certain areas ONLY, MAKING SURE the center link is tight. Adding to that is rear shocks of the same make as above, a rear sway bar, & poly track bar bushings.

   You WON'T believe the diff. in the way the car handles & feels. Almost like a modern day car with rack & pinion. It will feel better than your F-250 & almost as good as the Highlander.

   Just my thoughts as I've done them myself over the yrs. & have told MANY about the same.

 

 

Tom T.

 

 

[Turbinator]

On 11/6/2017 at 5:15 PM, telriv said:

Bob,

 

   One of the BIGGEST improvements you can make to your STOCK '63 Riv. is to install a newer steering box with LESS turns lock-lock.  You WON'T believe the diff.  Adding to that is Bilstein shocks or at least KYB's, a bigger front sway bar, poly bushings in certain areas ONLY, MAKING SURE the center link is tight. Adding to that is rear shocks of the same make as above, a rear sway bar, & poly track bar bushings.

   You WON'T believe the diff. in the way the car handles & feels. Almost like a modern day car with rack & pinion. It will feel better than your F-250 & almost as good as the Highlander.

   Just my thoughts as I've done them myself over the yrs. & have told MANY about the same.

 

 

Tom T.

 

 

Tom, great! All this is brand new news to me. I would not mind in the least doing some improvements to improve the handlings. Thanks a lot yet again. I’ll paper copy your recommendations and place them in my Riviera log book. Helps to keep records of what you’ve done to the car.

Red Riviera Bob

 

 

 

Edited October 3, 2019 by Turbinator (see edit history)

[NTX5467]

Tire Pressure --  The numbers I mentioned were with pre-P Metric tires, which had a max inflation pressure of 32psi.  And tires whose tread width was generally equal to the wheel's rim width, or thereabouts.

 

If the tires can go higher than 32psi, to 35psi, I don't think that's too much to get excited about.  Main difference might be a little more impact harshness and such at the higher pressures.  Key thing is the front/rear pressure relationship.  If the base pressure was 24psi, then the recommendation of "+4psi for high speed driving", then that's 28psi.  Then "+2" for the front".

 

The other consideration is making sure the tires were sized correctly for the load being carried.  In my case, it was H78x14 on a 4200 lb car, or similar.  Or a similar 15" size on a similar car of similar weight.  P225/75R-15 is kind of between the old H78-15 and J78-15 size, dimensionally.  The P235/75R-15 is the old L78-15 equivalent and a little larger than the P225/75R-15 size.  Theoretically, with the larger size, probably 2psi lower would work ok.  Again, just depends upon the "feel" that difference might make in ride and such.

 

The old recommendation was to run the P Metric tires at 2psi more than what you ran in the prior tires you had that were not P Metric.  Expanding my earlier pressure bias, then, would be 32/30, under that orientation.  Most cars, back then, were 55/45 front rear weight distribution, so my pressure bias would be pretty close.

 

If you normally use 35psi in 35psi-rated tires, going down to 32psi might make for s little smoother ride and still adequately support the car's weight . . . in general.  Now, IF you're going to run 90+mph for extended periods of time, higher pressures might be better.

 

NTX5467

[rodneybeauchamp]

Thanks for that info.

 

I recently fitted Gabriel gas shock absorbers all round, have put in new Moog poly sway bar bushes front only. Tyres were new 12 months ago, but still have few miles on them. 

 

Car came from factory with oversize whitewall and heavy duty springs and shocks.

 

The ride now is firm, almost harsh so thinking a lower tyre pressure might make for a bit more comfort. Certainly before the shockers were changed it felt softer, almost squishy at low speed over spoon drains and bigger bumps.

 

 Rear shockers were leaking on one side, fronts were old but still working.

 

Be interested to play with pressures this trip. Will try 32 up front and 30 at rear.

 

cheers Rodney ????

 

[OldGerman]

Hi Riviera Folks,

 

does anybody have a specification (Dimensions) of the front alignment hight tool?

Thank you

frank

 

[Turbinator]

Frank , private message Tom Telesco. Tom has the specs memorized for front end alignment for 63 Riviera with radial tires.

Turbinator

[OldGerman]

Have been at the wheel alignment shop today.

we tried to get as much positve caster as possible.

it was not possible to gain more than +1degree both sides without exceeding max. Shimming spec.

the car is sitting lower in the front at driver side. I guess the spring was sacking over time. 

I donˋt know what the previous drivers weight was 🤔😉

may need to shim the front spring as well some time....

By chance I researched this nice alignment shop with a very good modern optical and mechanical equipment.

It is transportabel and used on race tracks. The shop is specialized on Porsche and AMG‘s, located close to the Mercedes AMG plant.

The mechanic liked the Buick and the easy way how to adjust.

 

car runs straight and smooth. Job accomplished.

Thank you for this Thread which helped me a lot.

Frank

 

 

[KongaMan]

There are several ways to get more caster:

- Tighten the nuts on the reaction rods.

- Shorten the bushings on the reaction rods.

- Adjust the position of the upper control arm on the shaft to move the arm off-center and towards the rear.

 

The first two methods work by pulling the lower control arm forward.  There's some risk that this could compromise free rotation about the bushing, resulting in binding and/or distortion of the bushing.  The latter method changes the caster without affecting the alignment of the lower control arm and is, IMHO, preferable.

[60FlatTop]

Straight and smooth is the goal. It's a Riviera made for the boulevard, some forget that.

 

That i a really nice lift. I have been looking at low height four post lifts and that looks like a good one.

 

Good luck with the car. You appear to have found a good service garage.

 

Bernie

[RivNut]

Who determined the "max" you were exceeding?

[KongaMan]

1 hour ago, RivNut said:

Who determined the "max" you were exceeding?

IIRC, there's something in the FSM about not using more than x inches of shims.

Edited October 2, 2019 by KongaMan (see edit history)

[RivNut]

9 hours ago, Turbinator said:

Frank , private message Tom Telesco. Tom has the specs memorized for front end alignment for 63 Riviera with radial tires.

Turbinator

If you'll go to the second post in this thread, I posted a post within a post.  That post within a post has all of the front end specs copied and pasted into it.  Copy, paste, and print.  Take it to your alignment shop.

[telriv]

AND, who do you think told Russ about ail this???

[telriv]

I have run Poly bushings in my strut rods for 30+ years. To achieve positive 4 degrees of Caster I shortened the rear bushing by 1/4" which pulls the lower control arm forward. 

We ALL learn from each other. Nothing so new.

[RivNut]

2 minutes ago, telriv said:

AND, who do you think told Russ about ail this???

Well, I imagine that you did. But Russ had it in print and it was easy to copy and paste.  If it wasn't his discovery, he should at least give credit where credit is due. 😊

[telriv]

Very seldom does anyone do. Why do you think Clarke's has what they have & is mostly correct. It was a lot of my input 20+ yrs. ago.

[RivNut]

43 minutes ago, telriv said:

Very seldom does anyone do. Why do you think Clarke's has what they have & is mostly correct. It was a lot of my input 20+ yrs. ago.

That one I did know about.  Package tray I'm sure.  The rest is conjecture on my part.

 

Ed

[SwedeDownUnderR63]

43 minutes ago, telriv said:

Very seldom does anyone do. Why do you think Clarke's has what they have & is mostly correct. It was a lot of my input 20+ yrs. ago.

Here is one thank you as I have bought parts from Clarke’s and also had the caster adjusted based on your information. It is great to have all the information  and parts available today compared to what was available in Sweden between 1976 and 1982 when I had my first Riviera.

[Turbinator]

I put on the rebuilt Saginaw 808 I sent to Tom Telesco. Replaced the worn shocks with Bilsteins shocks,  replaced the bushing in the track bar, replaced worn rubber in the suspension on the front end. Had the front end aligned per spec. From Tom Telesco. The car steers with the front tires now and rides like the cruiser the 63 Riviera was intended to ride. 

All I will say is Tom Telesco is the best mechanic that ever worked on my car. Tom is a true professional dedicated to his craft.  

Turbinator

[OldGerman]

21 hours ago, KongaMan said:

There are several ways to get more caster:

- Tighten the nuts on the reaction rods.

- Shorten the bushings on the reaction rods.

- Adjust the position of the upper control arm on the shaft to move the arm off-center and towards the rear.

 

The first two methods work by pulling the lower control arm forward.  There's some risk that this could compromise free rotation about the bushing, resulting in binding and/or distortion of the bushing.  The latter method changes the caster without affecting the alignment of the lower control arm and is, IMHO, preferable.

 

I adjusted the upper control arm one turn out off center (to move the upper arm backwards). I guess a single turn was not enough. Unfortunately it is not possible to adjust this again while the care is  already on the lift in the alignment shop.

I would not go the way with pulling the lower control arm forwards  by the reaction rod. 

 

As sayed before in this thread, our Rivieras are cruisers, not made to race on the Nuerburgring 😉

So far I am happy with the result as it is for now.

It drives much better then before with its -1* caster.

The car runs straight and there is not to much understeer.

 

I drive slow anyhow 😁

 

Edited October 3, 2019 by OldGerman (see edit history)

[OldGerman]

20 hours ago, RivNut said:

Who determined the "max" you were exceeding?

 

Ed, 

shop manual states max 1/2“ of shims.

Over this point you are going to run out off thread on the bolts, or you need longer bolts.

Frank

[dr914]

On 11/6/2017 at 5:15 PM, telriv said:

Bob,

 

   One of the BIGGEST improvements you can make to your STOCK '63 Riv. is to install a newer steering box with LESS turns lock-lock.  You WON'T believe the diff.  Adding to that is Bilstein shocks or at least KYB's, a bigger front sway bar, poly bushings in certain areas ONLY, MAKING SURE the center link is tight. Adding to that is rear shocks of the same make as above, a rear sway bar, & poly track bar bushings.

   You WON'T believe the diff. in the way the car handles & feels. Almost like a modern day car with rack & pinion. It will feel better than your F-250 & almost as good as the Highlander.

   Just my thoughts as I've done them myself over the yrs. & have told MANY about the same.

 

 

Tom T.

 

 

and then of course to finish it off, disc brakes!!!

[KongaMan]

At some point, just buy an Acura.

[60FlatTop]

"What I am used to in my car that is 50 or 60 years newer" is not necessarily "better" it is what a person is "used to".

 

I have seen worn out old cars modified by people who never drove one in a proper state of repair.

 

The thought of converting to disc brakes because my drums might fade after multiple panic stops is just something that amuses me rather than perk my interest. What are you guys doing with your cars?

 

I drive my cars fairly fast, not 0-60, but 70-80 is not uncommon. I am not scared. They go where I point them, stop when I want, and get me home.

 

There is no control over the mental images that come to me, so when I read about these changes the image I get of an arm waving a ten gallon hat out the driver's window and hearing "Yahoo" yelled in the distance just comes to me naturally. Seems to go with the topic.

 

The idea of buying the Acura is a good one. I think I will get the stock 438 HP car out and take my wife to lunch. I doubt if I will used the multiple panic stop capability built into that one on the ride, either.

[KongaMan]

15 minutes ago, 60FlatTop said:

I have seen worn out old cars modified by people who never drove one in a proper state of repair.

 

Bingo.  People want to replace rather than repair.  Some guy buys a car off Craigslist that has been sitting in a garage for 15 years covered in boxes and he wonders why it won't stop on a dime.  So he condemns the braking system and the engineering behind it without ever learning how or how well it works and decides to replace it all with disc brakes.  Here's an alternative: new master cylinder, 3 new brake hoses, 4 new wheel cylinders, 2 sets of brake shoes, 4 drums turned, 1 quart of DOT3.  $225 and a Saturday afternoon, and all of a sudden you've got pretty good brakes and a lot better understanding of how the car was designed.

[Turbinator]

On 10/3/2019 at 11:52 AM, KongaMan said:

At some point, just buy an Acura.

I owned an Acura Legend awhile back. You know with the front wheel drive the Acura felt like I was driving my sofa.

i guess it is all in what you like or not like. Now I will say the Acura Legend had a good AC.

Turbinator

[Turbinator]

I took the 63 Red Riviera out for a run North to York PA to get some Berkible 2 + 2 gum cutter. I took Interstate 83. 

I needed to accelerate to move away from driving situation I thought dangerous. Between 80-90 mph the car felt a bit unstable.

i regularly drive 60-65 mph on the Interstate. The likes that speed and so do I.

ive decided to install sway bars front and back of the car. I believe it will make the car safer at higher speed. I won’t drive 80-90 mph as a general rule. When 18 wheelers are bearing down hard on me I want to move away safely.

Turbinator