Run Run Away

Question:

Today I am going to address suspension systems. In the beginning there was the solid axle.  Still used on some big rig trucks.  Very durable but rough riding.   Knee action independent suspension came along, popularized after WWII.  A refined version can be seen in the ‘82 Mercedes Benz.  Upper and lower control arms in sort of a parallelogram geometry.  Spring acts on lower control arm.  There is a robust steering knuckle and spindle for the wheel mount.  Very effective for its day.  A knee action suspension can frequently hold its alignment for the life of the car.  You will note the M.B. uses very refined forged arms instead of the usual pressed steel found on the American cars. McPherson struts came next, with huge savings to the manufacturers not passed along to the consumers.  Its an all-in-one assembly of spring and damper and sort of resembles the struts used on aircraft, from which I assume the design was adapted for cars.  Since this design is predominately in use today, I will delve into its serious deficiencies: 1. It will not hold alignment.  Mere friction is used at the two lower bolts, one an adjusting cam and the other a clamp bolt to hold the camber adjustment fixed.  A good bump or light curb hit can and will move the camber angle, requiring a new alignment job.  In contrast, the knee action used a micrometer screw or shims to affect adjustment, both very robust. Also, in the knee action system, caster could be adjusted; caster is fixed in McPherson suspensions. 2.  As the wheel undulates over bumps, the McPherson strut will alternately compress and extend and as it does so, the camber of the wheel is in constant change from its nominal zero degrees from vertical.  This produces a constant scrubbing action on the tire.  You can demonstate this by simply jouncing up and down on the front end or even better, jacking up and then lowering your front end.  Observe the wheel take on a pronounced positive camber as your jack up and then as you apply extra weight (simulating rebound), it will assume a pronounced negative camber.  With camber in a constant state of flux from neutral (where it should stay), to positive to negative, the tires wear out about double the rate they would if a constant zero camber could be maintained.  Knee action is guilty of the same fault. Only a true aircraft strut maintains a zero in all spring deflections or compressions.  Such a strut requires a scissors link and is more complex, of course, but the extra expense is indicated in $30,000 cars, if not in $8000 cars. You will note that year-to-year model changes no longer involve complete body style changes as in the 50’s.  Even in those days, the running gear remained largely unchanged, at least in principle; it was style that changed significantly from year-to-year.  Even today, with the style changes taking several years, the running gear is carried over as long as the factory can possibly  can get away with.  Suspension systems are at least 50 years out of date.  Now you know why radial tires should provide at least 100,000 miles of service but don’t.  Now you know why your wheels are always out of alignment.  Its the McPherson strut.

Response:

Read out of a Machinery’s Handbook while sitting in the office every morning like I do and you will greatly profit from it.

Seems like the best part of your brain got flushed away at some point…

Response:

Bill Putney posted: As you point out in your next post, there is some adjustment of caster on the LH vehicles by shifting the engine cradle as allowed by the 4 bolt to hole clearances (but shops don’t know about this, or don’t admit to knowing).  This fix is in fact documented in TSB #02-16-99 and a repair procedure referenced in that TSB.

Using undersized bolts in oversized holes = an engineer with a hole in his head who signed off on that one.  Any SAE engineer will agree it goes against all acceptable standards, both automotive, aircraft, marine, and in most instances of general machinery.  Anything placed in a hole should fit nice and snug: rivets, bolts, threaded cap screw, wire harnesses into grommets, etc. ad infinitum.  Read out of a Machinery’s Handbook while sitting in the office every morning like I do and you will greatly profit from it. The camber adustment with excentric is basically the same error because it uses an oversized hole.  Using two excentrics compounds the madness. I have frequently used aircraft design, fabrication, and assembly processes as good examples for auto factories to follow, even if "watered down" in their approach.  The exchange above by other posters reinforces my position that almost nothing on cars would be allowed on airplanes and for very good reason.  Cars are, have been, and if the current attitude prevails, always will be inferior machines of questionable roadworthiness and doubful value. I have essentially given up on cars and resigned myself to go with the flow, capitalizing on my ability to keep earlier, cheaper models on the road for my personal transportation.  The ones who suffer the most are those good-intentioned buyers who lay down $30,000 for new cars in hopes that their families will enjoy safe, reliable, if not cheap transportation. They are the ones shortchanged, not I.

Response:

Funny.  Just had alignment checked on my ‘00 Intrepid and caster IS adjustable from 2 to 4 degrees positive, with ideal at 3.  Requires replacement of the original strut clevis to knuckle attachment bolts with undersized bolts. The undersized bolts are to allow camber adjustment. There is no published procedure on a 2000 Intrepid for caster adjustment.  There is a specified range as cited above.

Actually, the car comes from the factory with one eccentric bolt and one non-eccentric bolt holding the knuckle to the strut, and they replace the non-eccentric bolt with an eccentric bolt to double the range of adjustment of the camber. As you point out in your next post, there is some adjustment of caster on the LH vehicles by shifting the engine cradle as allowed by the 4 bolt to hole clearances (but shops don’t know about this, or don’t admit to knowing).  This fix is in fact documented in TSB #02-16-99 and a repair procedure referenced in that TSB. Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x") —–= Posted via Newsfeeds.Com, Uncensored Usenet News =—– http://www.newsfeeds.com – The #1 Newsgroup Service in the World! —–==  Over 100,000 Newsgroups – 19 Different Servers! =—–

Response:

Will double check with shop.  They said it’s possible.

No doubt that it’s possible by shifting the sub-frame forward or back, but caster is not going to change by replacing with the previously mentioned strut to knuckle bolts.

Response:

The cars I’ve had over the last 15 years have held alignment much MUCH better (and longer) than anything I owned in the 60’s and 70’s.  I don’t know what you’re talking about.

I’ve never had anything hold alignment BETTER than a torsion-bar Chrysler from the 60s/70s (NOT the F/M/J transverse T-bar setup, but the A/B/C/E/R body longitudinal setup). But my ‘93 has held alignment AS WELL as the old cars. However, if you read some of the trade magazines there are quite a few modern cars that are problem children when it comes to alignments. Limited range of camber adjustment, NO provision for camber adjustment, etc. etc. Moog and other companies are making good money on ‘problem solver’ kits that have offset cam bolts that allow you to add adjustment capability to these cars.

Response:

Will double check with shop.  They said it’s possible. – Hide quoted text — Show quoted text – Funny.  Just had alignment checked on my ‘00 Intrepid and caster IS adjustable from 2 to 4 degrees positive, with ideal at 3.  Requires replacement of the original strut clevis to knuckle attachment bolts with undersized bolts. The undersized bolts are to allow camber adjustment. There is no published procedure on a 2000 Intrepid for caster adjustment.  There is a specified range as cited above.

Response:

Funny.  Just had alignment checked on my ‘00 Intrepid and caster IS adjustable from 2 to 4 degrees positive, with ideal at 3.  Requires replacement of the original strut clevis to knuckle attachment bolts with undersized bolts.

The undersized bolts are to allow camber adjustment. There is no published procedure on a 2000 Intrepid for caster adjustment.  There is a specified range as cited above.

Response:

Funny.  Just had alignment checked on my ‘00 Intrepid and caster IS adjustable from 2 to 4 degrees positive, with ideal at 3.  Requires replacement of the original strut clevis to knuckle attachment bolts with undersized bolts. – Hide quoted text — Show quoted text – caster is fixed in McPherson suspensions.

Response:

The cars I’ve had over the last 15 years have held alignment much MUCH better (and longer) than anything I owned in the 60’s and 70’s.  I don’t know what you’re talking about.

Don’t feel bad, he doesn’t know what he’s talking about either.  At least you have the ability to see it.  Sadly , he doesn’t. Tom Heintz   "Mopar Maniac"

Response:

Today I am going to address suspension systems. Why???

Give it up, he’s high on Cheetos, Ted

Response:

The cars I’ve had over the last 15 years have held alignment much MUCH better (and longer) than anything I owned in the 60’s and 70’s.  I don’t know what you’re talking about.

Response:

Today I am going to address suspension systems.

Why???

Response:

Today I am going to address suspension systems. In the beginning there was the solid axle.  Still used on some big rig trucks.  Very durable but rough riding.   Knee action independent suspension came along, popularized after WWII.  A refined version can be seen in the ‘82 Mercedes Benz.  Upper and lower control arms in sort of a parallelogram geometry.  Spring acts on lower control arm.  There is a robust steering knuckle and spindle for the wheel mount.  Very effective for its day.  A knee action suspension can frequently hold its alignment for the life of the car.  You will note the M.B. uses very refined forged arms instead of the usual pressed steel found on the American cars. McPherson struts came next, with huge savings to the manufacturers not passed along to the consumers.  Its an all-in-one assembly of spring and damper and sort of resembles the struts used on aircraft, from which I assume the design was adapted for cars.  Since this design is predominately in use today, I will delve into its serious deficiencies: 1. It will not hold alignment.  Mere friction is used at the two lower bolts, one an adjusting cam and the other a clamp bolt to hold the camber adjustment fixed.  A good bump or light curb hit can and will move the camber angle, requiring a new alignment job.  In contrast, the knee action used a micrometer screw or shims to affect adjustment, both very robust. Also, in the knee action system, caster could be adjusted; caster is fixed in McPherson suspensions. 2.  As the wheel undulates over bumps, the McPherson strut will alternately compress and extend and as it does so, the camber of the wheel is in constant change from its nominal zero degrees from vertical.  This produces a constant scrubbing action on the tire.  You can demonstate this by simply jouncing up and down on the front end or even better, jacking up and then lowering your front end.  Observe the wheel take on a pronounced positive camber as your jack up and then as you apply extra weight (simulating rebound), it will assume a pronounced negative camber.  With camber in a constant state of flux from neutral (where it should stay), to positive to negative, the tires wear out about double the rate they would if a constant zero camber could be maintained.  Knee action is guilty of the same fault. Only a true aircraft strut maintains a zero in all spring deflections or compressions.  Such a strut requires a scissors link and is more complex, of course, but the extra expense is indicated in $30,000 cars, if not in $8000 cars. You will note that year-to-year model changes no longer involve complete body style changes as in the 50’s.  Even in those days, the running gear remained largely unchanged, at least in principle; it was style that changed significantly from year-to-year.  Even today, with the style changes taking several years, the running gear is carried over as long as the factory can possibly  can get away with.  Suspension systems are at least 50 years out of date.  Now you know why radial tires should provide at least 100,000 miles of service but don’t.  Now you know why your wheels are always out of alignment.  Its the McPherson strut.

Response:

Today I am going to address suspension systems.

Why???

Response:

Today I am going to address suspension systems. Why???

Give it up, he’s high on Cheetos, Ted

Response:

The cars I’ve had over the last 15 years have held alignment much MUCH better (and longer) than anything I owned in the 60’s and 70’s.  I don’t know what you’re talking about.

Response:

The cars I’ve had over the last 15 years have held alignment much MUCH better (and longer) than anything I owned in the 60’s and 70’s.  I don’t know what you’re talking about.

Don’t feel bad, he doesn’t know what he’s talking about either.  At least you have the ability to see it.  Sadly , he doesn’t. Tom Heintz   "Mopar Maniac"

Response:

Funny.  Just had alignment checked on my ‘00 Intrepid and caster IS adjustable from 2 to 4 degrees positive, with ideal at 3.  Requires replacement of the original strut clevis to knuckle attachment bolts with undersized bolts. – Hide quoted text — Show quoted text – caster is fixed in McPherson suspensions.

Response:

Funny.  Just had alignment checked on my ‘00 Intrepid and caster IS adjustable from 2 to 4 degrees positive, with ideal at 3.  Requires replacement of the original strut clevis to knuckle attachment bolts with undersized bolts.

The undersized bolts are to allow camber adjustment. There is no published procedure on a 2000 Intrepid for caster adjustment.  There is a specified range as cited above.

Response:

Will double check with shop.  They said it’s possible. – Hide quoted text — Show quoted text – Funny.  Just had alignment checked on my ‘00 Intrepid and caster IS adjustable from 2 to 4 degrees positive, with ideal at 3.  Requires replacement of the original strut clevis to knuckle attachment bolts with undersized bolts. The undersized bolts are to allow camber adjustment. There is no published procedure on a 2000 Intrepid for caster adjustment.  There is a specified range as cited above.

Response:

The cars I’ve had over the last 15 years have held alignment much MUCH better (and longer) than anything I owned in the 60’s and 70’s.  I don’t know what you’re talking about.

I’ve never had anything hold alignment BETTER than a torsion-bar Chrysler from the 60s/70s (NOT the F/M/J transverse T-bar setup, but the A/B/C/E/R body longitudinal setup). But my ‘93 has held alignment AS WELL as the old cars. However, if you read some of the trade magazines there are quite a few modern cars that are problem children when it comes to alignments. Limited range of camber adjustment, NO provision for camber adjustment, etc. etc. Moog and other companies are making good money on ‘problem solver’ kits that have offset cam bolts that allow you to add adjustment capability to these cars.

Response:

Will double check with shop.  They said it’s possible.

No doubt that it’s possible by shifting the sub-frame forward or back, but caster is not going to change by replacing with the previously mentioned strut to knuckle bolts.

Response:

Funny.  Just had alignment checked on my ‘00 Intrepid and caster IS adjustable from 2 to 4 degrees positive, with ideal at 3.  Requires replacement of the original strut clevis to knuckle attachment bolts with undersized bolts. The undersized bolts are to allow camber adjustment. There is no published procedure on a 2000 Intrepid for caster adjustment.  There is a specified range as cited above.

Actually, the car comes from the factory with one eccentric bolt and one non-eccentric bolt holding the knuckle to the strut, and they replace the non-eccentric bolt with an eccentric bolt to double the range of adjustment of the camber. As you point out in your next post, there is some adjustment of caster on the LH vehicles by shifting the engine cradle as allowed by the 4 bolt to hole clearances (but shops don’t know about this, or don’t admit to knowing).  This fix is in fact documented in TSB #02-16-99 and a repair procedure referenced in that TSB. Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x") —–= Posted via Newsfeeds.Com, Uncensored Usenet News =—– http://www.newsfeeds.com – The #1 Newsgroup Service in the World! —–==  Over 100,000 Newsgroups – 19 Different Servers! =—–

Response:

Bill Putney posted: As you point out in your next post, there is some adjustment of caster on the LH vehicles by shifting the engine cradle as allowed by the 4 bolt to hole clearances (but shops don’t know about this, or don’t admit to knowing).  This fix is in fact documented in TSB #02-16-99 and a repair procedure referenced in that TSB.

Using undersized bolts in oversized holes = an engineer with a hole in his head who signed off on that one.  Any SAE engineer will agree it goes against all acceptable standards, both automotive, aircraft, marine, and in most instances of general machinery.  Anything placed in a hole should fit nice and snug: rivets, bolts, threaded cap screw, wire harnesses into grommets, etc. ad infinitum.  Read out of a Machinery’s Handbook while sitting in the office every morning like I do and you will greatly profit from it. The camber adustment with excentric is basically the same error because it uses an oversized hole.  Using two excentrics compounds the madness. I have frequently used aircraft design, fabrication, and assembly processes as good examples for auto factories to follow, even if "watered down" in their approach.  The exchange above by other posters reinforces my position that almost nothing on cars would be allowed on airplanes and for very good reason.  Cars are, have been, and if the current attitude prevails, always will be inferior machines of questionable roadworthiness and doubful value. I have essentially given up on cars and resigned myself to go with the flow, capitalizing on my ability to keep earlier, cheaper models on the road for my personal transportation.  The ones who suffer the most are those good-intentioned buyers who lay down $30,000 for new cars in hopes that their families will enjoy safe, reliable, if not cheap transportation. They are the ones shortchanged, not I.

Response:

Read out of a Machinery’s Handbook while sitting in the office every morning like I do and you will greatly profit from it.

Seems like the best part of your brain got flushed away at some point…

Response: