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11/26/2019 10:21 AM  #26


Re: Adding caster to upper control arms

MS wrote:

 
How is it possible for caster to be different than steering access inclination. Are they not the same thing?

No, they are different angles. Caster is the angle of the ball joints when viewed from the side, while steering axis inclination is the angle viewed from the front or rear.


Bob. 69 Mach 1, 393W, FMX, Armstrong  steering.
 

11/26/2019 11:04 AM  #27


Re: Adding caster to upper control arms

MS wrote:

TKOPerformance wrote:

MS wrote:

Observations from my direct experience on my 66...

Using adjustable strut rods makes it easier to pull the lower ball joint forward, BUT it also puts the lower control arm pivot bushing in a pretty good bind and can cause it to work loose from the control arm. I wound up tack-welding the pivot bushings in the LCA so they could not slide. I was still not happy with the resulting bind with five degrees caster. I wound up going with 3.5 degrees caster to lessen the problem. A LCA with a spherical rod end will eliminate that problem, but I would not wish those on anybody who wants a car that is comfortable to drive on the street.

You are asking for trouble if you go with more than one revolution off center on the upper control arm bushings. One bushing starts getting short of threads.

Moving the bottom ball joint forward without moving the lower ball joint rearward an equal amount repositions the wheel front-back in the wheelwell and can cause tire rub issues at the lower front corner of the fender.

I have not noticed any discernible driving differences in my car With 3.5 degrees caster or with five degrees caster.

3.5 degrees is easy to get without taking extreme measures, so my conservative side says that is the best number to shoot for.

A small digital level attached to the bottom of your spindle will give you a baseline measurement. Make your changes and take another reading. The difference is the amount of change your modification achieved.

MS, you ever try one of these in a control arm application:

https://metalcloak.com/metalcloak-duroflex-joints-suspension-builder-parts.html

The idea is that they provide the highway ride of a rubber bushing with the greater articulation of a rod end.  A lot of off road guys swear by them.
 

Looks like something that might work for LCA bushing and strut rod bushing..  I wonder how they do on rotational?  Where does it rotate?
 

Not sure, but control arms is typically where I've seen them used.  Vehicles like Jeep TJs with link suspensions often have them in aftermarket or custom made links, usually with length other than stock as part of a lift.  So in rotation I can't say if what's happening is the rubber flexing, or if the sleeve is rotating on the bolt securing it. 

 

11/26/2019 11:10 AM  #28


Re: Adding caster to upper control arms

lowercasesteve wrote:

Question.

Why do you need so much caster?

I've been running about 3 deg for the last number of decades.  Mullholland Dr, Angeles Crest, and numerous roads up here in NorCal.  Never had a problem with return to center.  Even now on city streets I don't even think about it.

Would someone enlighten me.

Thanks.

The reason I've always heard cited was twofold.  First was return to center, but how much achieves acceptable return to center is going to vary due to a lot of things.  For example, if the idler arm in the steering is designed to return the steering to center you probably van get away with very little positive caster, because the idler is doing the work for the system.  This is how stock systems used almost no caster, sometimes even negative caster.  That was '50s and '60s era American steering where they wanted grandma to be able to turn the car with her pinky. 

Second is to help the car track straight at speed.  Again, a lot of variables here, but more positive caster tends to make the front end less wander prone. 

Another thing worth noting is that the factory alignment specs were designed for use with bias ply tires, which had quite different handling characteristics than radials. 

 

11/26/2019 12:14 PM  #29


Re: Adding caster to upper control arms

I think a possible solution is the offset balljoints made for jeep alignment problems.  I remember one looked like it was set up to fit in a steel ring and had a cap and nut hold it in place.  A control arm could easily be modified to accept that joint.   Then you would pretty much have 360 degree adjustability with it.   It could solve caster problems, or cars with camber issues.   Would like to get a hold of one of those to measure the tapers.   It just seems like over thinking an issue to me anymore.

Last edited by Greg B (11/26/2019 12:14 PM)


If multiple things can go wrong, the one that will go wrong will be the one that causes the most damage.
 

11/26/2019 3:04 PM  #30


Re: Adding caster to upper control arms

Bearing Bob wrote:

DC wrote:

  I went round and round with all this stuff and finally ended up making custom upper control arms with tubing. That was a few years ago and I have since done the Mustang II conversion (with custom upper control arms). Both ways, 8 degrees of positive caster is easy to get. With 5 degrees of negative camber track days on those Hoosier DOT race tires are awesome.

FIVE? 5? Degrees of negative caster? Not .5°? Wow! I ran 1.5° for a while and thought that was a lot.

I also have tubular arms, with 1" UCA ball joint rear offset and 1/2" LCA bj front offset. 8° caster and -.5° camber. I too couldn't feel the change in caster, even with manual steering. I suppose there might come a time when I don't like great handling and return my 69 to stock suspension.

I don't think it would be terribly difficult to offset the ball joints on stock control arms. That way you could keep those granny ride rubber bushings The smiley face means I'm kidding. The way we set up our cars is after all personal preference. My thinking is if your car rides too soft or too firm, change it to your liking.

8 degrees positive caster, 5 degrees negative camber....  I do run more negative camber at times to get the entire surface of the tire up to temperature. This is a race set-up. The positive caster helps the car to point in to a corner, the negative camber helps the whole tire work not jut the outside shoulder. I only run around five degrees positive camber on the street and about one and a quarter degree of negative camber. The caster really helps keep the steering system loaded in one direction while you are going down the road to help eliminate wander and vibrations.

 

11/26/2019 9:52 PM  #31


Re: Adding caster to upper control arms

What purposes do the strut rods serve?


65 coupe, 5.0L, T5, 3.25 Currie traction lock, strong arming for now
     Thread Starter
 

11/26/2019 10:14 PM  #32


Re: Adding caster to upper control arms

SO AFTER ALL THIS DISCUSSION ....I AM CONFUSED. I AM ABOUT T PUT NEW UPPER AND LOWER A FRAMES ,NEW TIE ROD ENDS MY QUESTION IS WHAT ARE THE LINE UP SPECS OR JUST USE THE OLD ONES THAT PEOPLE NORMALLY DID FOR THE SHELBY DROP. I HAVE ADJUSTABLE STRUT RODS AND ROLLER SPRING PERCHES ON CAR.


I AM NOT SHOUTING...THIS IS THE WAY I TALK & DONT EVER ASK FOR SWEET TEA IN ILLINOIS!
 

11/26/2019 11:52 PM  #33


Re: Adding caster to upper control arms

DC wrote:

the negative camber helps the whole tire work not jut the outside shoulder.

Oh there's no doubt negative camber helps the tires work, I was just flummoxed by the amount.  Have you ever tired a bit of static toe out? It really helps the car turn in by giving it more Ackerman. Too much makes it quite squirrelly.


Bob. 69 Mach 1, 393W, FMX, Armstrong  steering.
 

11/27/2019 6:25 AM  #34


Re: Adding caster to upper control arms

Nos681 wrote:

What purposes do the strut rods serve?

To triangulate the mounting of the LCA and keep it from bending, and to allow for caster adjustment on cars that have adjustable ones.

 

11/27/2019 6:27 AM  #35


Re: Adding caster to upper control arms

BILLY WALTON from GEORGIA wrote:

SO AFTER ALL THIS DISCUSSION ....I AM CONFUSED. I AM ABOUT T PUT NEW UPPER AND LOWER A FRAMES ,NEW TIE ROD ENDS MY QUESTION IS WHAT ARE THE LINE UP SPECS OR JUST USE THE OLD ONES THAT PEOPLE NORMALLY DID FOR THE SHELBY DROP. I HAVE ADJUSTABLE STRUT RODS AND ROLLER SPRING PERCHES ON CAR.

My advice would be 3.5 degrees positive caster (I like another 0.25 degrees positive on the RH side to account for road crown), 0-0.5 degrees negative camber, and 1/8" toe in (1/16" per side, plus make sure the steering is truly centered before messing with toe). 
 

 

11/27/2019 8:26 AM  #36


Re: Adding caster to upper control arms

I prefer zero camber. No sense adding extra wear to the inside edge of the tires for the very small gain you might receive.
3.5 pos caster
Zero camber
1/8” toe in


Money you enjoy wasting is NOT wasted money... unless your wife finds out.
 

11/27/2019 10:11 AM  #37


Re: Adding caster to upper control arms

Bearing Bob wrote:

DC wrote:

the negative camber helps the whole tire work not jut the outside shoulder.

Oh there's no doubt negative camber helps the tires work, I was just flummoxed by the amount. Have you ever tired a bit of static toe out? It really helps the car turn in by giving it more Ackerman. Too much makes it quite squirrelly.

 On the race car I always set the bump steer to toe out a bit on bump. That really helps if your car has an abrupt transition from corner entry understeer to corner exit oversteer, which Mustangs tend to do. I always go as close to neutral as I can on toe. Sometimes the car will wander a bit without some toe. On the front drivers toe out seems to work.

 

11/27/2019 11:36 AM  #38


Re: Adding caster to upper control arms

Bearing Bob wrote:

DC wrote:

the negative camber helps the whole tire work not jut the outside shoulder.

Oh there's no doubt negative camber helps the tires work, I was just flummoxed by the amount.  Have you ever tired a bit of static toe out? It really helps the car turn in by giving it more Ackerman. Too much makes it quite squirrelly.

 
Flummoxed and squirrelly in same post?😂


65 coupe, 5.0L, T5, 3.25 Currie traction lock, strong arming for now
     Thread Starter
 

11/27/2019 10:21 PM  #39


Re: Adding caster to upper control arms

Yep, I've got 50 cent words, and 5 cent words.


Bob. 69 Mach 1, 393W, FMX, Armstrong  steering.
 

11/28/2019 8:52 AM  #40


Re: Adding caster to upper control arms

TKO quote

“MS....

https://metalcloak.com/metalcloak-duroflex-joints-suspension-builder-parts.html

The idea is that they provide the highway ride of a rubber bushing with the greater articulation of a rod end.  A lot of off road guys swear by them.”


Looks very similar to engine mounts on newer cars to isolate engine vibration to body.
For use at the rear or elsewhere would be fine or for off-road as designed.

What happens to center sleeve during failure?
If it allows forward or rearward motion, it could put you into a ditch or worse case head on to semi truck.

Last edited by Nos681 (11/28/2019 8:57 AM)


65 coupe, 5.0L, T5, 3.25 Currie traction lock, strong arming for now
     Thread Starter
 

11/28/2019 12:52 PM  #41


Re: Adding caster to upper control arms

Nos681 wrote:

TKO quote

“MS....

https://metalcloak.com/metalcloak-duroflex-joints-suspension-builder-parts.html

The idea is that they provide the highway ride of a rubber bushing with the greater articulation of a rod end.  A lot of off road guys swear by them.”


Looks very similar to engine mounts on newer cars to isolate engine vibration to body.
For use at the rear or elsewhere would be fine or for off-road as designed.

What happens to center sleeve during failure?
If it allows forward or rearward motion, it could put you into a ditch or worse case head on to semi truck.

 They would need to be installed with the line of force perpendicular to the bearing access.


Money you enjoy wasting is NOT wasted money... unless your wife finds out.
 

11/28/2019 7:49 PM  #42


Re: Adding caster to upper control arms

I think failure would be extremely unlikely.  These things are in off road vehicles being acted upon by thousands of lb/ft of torque.  If the thought process is that its at low speed; torque is torque.  IME nothing breaks parts like off roading.  If it survives in that environment I can't imagine it failing on the street, or even the track. 

If it did fail I don't think it would be any more or less hazardous that if a rod end failed, and they are used in suspension applications all the time. 

 

11/28/2019 8:13 PM  #43


Re: Adding caster to upper control arms

I understand that it can handle the torque.

Are the bushing mounted in a front to rear on the off road vehicles you mention?
similar to how lower control arms are setup on mustang?


65 coupe, 5.0L, T5, 3.25 Currie traction lock, strong arming for now
     Thread Starter
 

11/29/2019 12:51 AM  #44


Re: Adding caster to upper control arms

Dan there's a you tube video in the link or provided that explains your questions. Short answer is yes.


Bob. 69 Mach 1, 393W, FMX, Armstrong  steering.
 

11/29/2019 9:31 AM  #45


Re: Adding caster to upper control arms

I will check it out, thanks Bob.


65 coupe, 5.0L, T5, 3.25 Currie traction lock, strong arming for now
     Thread Starter
 

8/12/2020 9:23 PM  #46


Re: Adding caster to upper control arms

MS wrote:

I prefer zero camber. No sense adding extra wear to the inside edge of the tires for the very small gain you might receive.
3.5 pos caster
Zero camber
1/8” toe in

SO AFTER PUTTING MY ADJUSTABLE STRUT RODS ON A YEAR LATER THE SHIMS PASSENGER SIDE FELL OUT ....READING SOME OF THIS HAS ME WONDERING...ARE YOU SUPPOSED T LEAVE THE SHIMS OUT AND USE THE STRUT RODS TO ADJUST.


I AM NOT SHOUTING...THIS IS THE WAY I TALK & DONT EVER ASK FOR SWEET TEA IN ILLINOIS!
 

8/12/2020 10:46 PM  #47


Re: Adding caster to upper control arms

You would still use shims to set camber.  There was some discussion about this on another thread.  Seems the strut rods are supposed to be used for fine tuning, but on a '67-up that had adjustable strut rods from the factory the strut rods are the only way caster is adjusted.  I can't see how that's fine for those cars and not okay for the earlier ones retrofitted with adjustable strut rods.  IMO the fewer shims the better. 

 

8/12/2020 11:08 PM  #48


Re: Adding caster to upper control arms

I FEEL LIKE THE AJUSTABLE STRUT RODS ON MINE HAVE WORN AND ARE NOT AS SMOOTH A RIDE AS MS SAID


I AM NOT SHOUTING...THIS IS THE WAY I TALK & DONT EVER ASK FOR SWEET TEA IN ILLINOIS!
 

8/13/2020 12:14 AM  #49


Re: Adding caster to upper control arms

Winter 2019 I rebuilt my front suspension.

Upper control arms:
stock style arms, control shaft offset one full revolution ( forward respectively per side), minor clearancing on upper control arm in tower area, new Moog ball joint, slight modifications to ball joint dome so it would not protrude further than ball joint housing ( wanted additional clearance to 18” wheels...not absolutely necessary), added grease groove as described by MS to control shaft, Arning/ Shelby 1” drop was done a few years ago.

Lower control arm:
New Moog stock replacement lower arm, installed Energy Suspension pivot bushing

Strut rod:
Stock strut rods with poly bushings.

Used a moly based paste/ lube on strut rod bushings and all poly sway bar bushings, supplied grease with Energy Suspension lower pivot bushing, moly fortified grease at control arms and ball joints.

Before bolting on sway bar and steering linkage, I can easily move the spindle through its full range of motion with strut rods connected.  I can even hit the bump stops fairly easy.

I now have the Viking coil over for small block.
Wanted to experiment with ride height in the front.
I haven’t had time to play with it this year, thanks to work and moving.
I like them very much.
I have them adjusted toward the softer end of the spectrum for now.


65 coupe, 5.0L, T5, 3.25 Currie traction lock, strong arming for now
     Thread Starter
 

Board footera


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