Front suspension rebuild?

tbm3fan

Old Man with a Hat
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I spent several hours looking over the different parts and suppliers to rebuild my original front suspension and have a question. I already decided to get the Firm Feel Stage 1 power steering box. Also decided on their upper control arms so I have more control over alignment. After that there is the general suspension kit. Question is where should poly bushings be Ok and where should rubber bushings be best? This is generally a highway car so firmer steering (the new box) and a better sense of planted on the road for cruising. So not like my 2004 Focus ZTS but more like my 2004 Buick LeSabre in ride which isn't bad. Thinking of acquiring parts while I work on assembling my 410 and then switch out the big Merc for the big Dodge.
 
I spent several hours looking over the different parts and suppliers to rebuild my original front suspension and have a question. I already decided to get the Firm Feel Stage 1 power steering box. Also decided on their upper control arms so I have more control over alignment. After that there is the general suspension kit. Question is where should poly bushings be Ok and where should rubber bushings be best? This is generally a highway car so firmer steering (the new box) and a better sense of planted on the road for cruising. So not like my 2004 Focus ZTS but more like my 2004 Buick LeSabre in ride which isn't bad. Thinking of acquiring parts while I work on assembling my 410 and then switch out the big Merc for the big Dodge.
What I can say from experience is that urethane strut rod bushings should never be used as it will seem that every bump in the road will transmit a huge impact to the passenger compartment and turn a previously quiet car into one that transmits too much noise. Wherever urethane bushings are used they tend to transmit a squeaking noise constantly going down the road unless they are greased regularly and the ride will be compromised as well - but some would say they help with the handling feel to be somewhat firmer.
 
Stay with rubber bushings!
rare parts and firm feel is where I got most of my steering and suspension parts from when I did my full overhaul and quality seemed good. I would get the weld on lower control arm plates when you take them off, it helps with the slop flex in those. Add the firm feel sway bars if you dont have them already too.
 
As to the urethane vs rubber, I concur with @saforwardlook on his orientation. I came to this conclusion decades ago regarding my '77 Camaro (which one of my friends, who had a '78 Z/28, said the "F" in GM's F-body designation meant "flex"). At the time, it was a popular modification to put solid body mounts on the Gen I (1967-69) and Gen II (1970-81) cars to "tighten things up". I'm thinking that with those solid mounts, it would transfer forces into the body where they were not meant to be, so that was not good for the body structure.

So, my orientation became that if the rubber was at a pivot point (as upper control arm bushings), that might be a good place for the urethane bushings. But where many people put them on race car chassis was on the lower control arm bushings, for better "location" and less deflection under load. Which WILL affect how much of the road is felt inside the car. On a race car, such feedback can be desired, but in a street car, NOT.

As to body mounts, the bottom part of the mount can be about "location", but the upper half of the mount is about "insulation". So the bottom can be urethane, as the upper part is rubber.

ONE place that urethane is advantageous is on the link bolt grommets at the end of sway bars, where they attach to the lower control arm on GM front suspensions, for example. The addition of the polyurethane bushings makes the bar act 20% larger than it would with rubber grommets. And they are inexpensive, too! The white GM grommets are stiffer than the light blue ones that Moog sells in their kits.

Now, one reason that people now feel their Chryslers are sloppy in handling, when they were new, to be firm and not sloppy. With a firm, but compliant, ride. GM's were "soft and sloppy", by comparison. Fords were "soft and understeered".

So, all things considered, stay with the good quality of rubber bushings and such. KYBs are supposed to be about 25% stiffer than stock, so that will compliment things, too. Then keep the tire pressures in the 32psi range for P-Metric radials.

As for "more caster", not needed. Reason is the Chrysler front suspension geometry. On the GM cars it really works on, when the chassis leans into a corner, the tires lean with it. On Chryslers, the outside wheel goes into negative camber as the inside wheel goes into positive camber, which means that as the body leans, the wheels become more perpendicular to the road surface, so the outer wheel's sidewall is better braced against cornering forces. THAT is the key to why they have better steering response. On GM front suspensions (as my Camaro has), adding caster into the mix gets to the same things as the Chrysler front end has had, by design. Too much caster can also cause the outer tread ribs to wear faster, too, as the car chassis stays flat, yet the wheels camber more than normal in turns.

Just some thoughts and experiences,
CBODY67
 
So the consensus is:
1. Upgrading the power steering box is Ok.
2. Poly bushings on the sway bar are fine which I expect since all my cars have poly there.
3. Tubular upper control arms not needed.
4. Upper control arm bushings in poly are Ok?
5. Strut rod bushings in rubber. Idler arm in rubber.
6. Lower control arm bushing in rubber along with plates to strengthen.

On my Parklane the redone front also has rubber all around except the sway bar. The rear has had all the stamped control arms replaced ( two lower, one upper, and one panhard) and all bushings are poly which total eight. Although those parts are designed to keep the rear axle in place. Car rides well and quiet but is a very different ride from the Polara. The 65 F-100 has poly bushings for the I beams and radius arms. It is a truck so rides like a truck but is dead quiet in the front even going over a speed bump with not a sound heard. That amazed me compared to stock. Of course they were terribly shot.
 
I would not use poly on the upper control arm bushings. They, like the lower bushings, flex too much. I thought that if you go with poly lower bushings that you needed to also go with the greasable pivot shaft? I'm still sorting out a problem with my PS gearbox, and maybe I won't feel this way after I get that fixed, but looking back I might have installed the offset UCA bushings instead of the regular bushings (to get more caster). I did weld a small extra plate (3/16) to the LCA to where I think it will do the most good:

354.jpg
 
So the consensus is:
1. Upgrading the power steering box is Ok.
2. Poly bushings on the sway bar are fine which I expect since all my cars have poly there.
3. Tubular upper control arms not needed.
4. Upper control arm bushings in poly are Ok?
5. Strut rod bushings in rubber. Idler arm in rubber.
6. Lower control arm bushing in rubber along with plates to strengthen.

On my Parklane the redone front also has rubber all around except the sway bar. The rear has had all the stamped control arms replaced ( two lower, one upper, and one panhard) and all bushings are poly which total eight. Although those parts are designed to keep the rear axle in place. Car rides well and quiet but is a very different ride from the Polara. The 65 F-100 has poly bushings for the I beams and radius arms. It is a truck so rides like a truck but is dead quiet in the front even going over a speed bump with not a sound heard. That amazed me compared to stock. Of course they were terribly shot.
Your Ford products are all body/frame vehicles. Ford paid extra attention to sound control from 1965 onward in their full-size cars. Harder to do on a UniBody Chrysler product without large amounts of under-carpet padding and such and the 1970 Torsion-Quiet Ride items.

One main issue with the dual front I-beam suspension those pickups had on them is "sagging coil springs". When the front springs sag, with age and wear, the caster goes away and the camber gets out of whack, which is why the beams must be bent in many cases to get the adjustability back. I had a friend who ran a Firestone store for a good while. He said that rather than bend the beams, to just put "load leveler" shocks on the front. That would usually raise the front end to it was more like original, then.

Take care,
CBODY67
 
I would stay away from the poly bushings all together. When I rebuilt mine about 15 years ago I used all rubber and it is still driving like a new car. I know of a few guys who used poly bushings and they were not happy with the results and the extra work it took to install them. Contact Craig @mobileparts and he can get you all of the components you need and they are of the higher quality older stock, not a lot of the imported junk you may get in a kit today. His prices are good and service is excellent. A lot of us here have dealt with him over the years. Good luck and keep us posted.
 
Your Ford products are all body/frame vehicles. Ford paid extra attention to sound control from 1965 onward in their full-size cars. Harder to do on a UniBody Chrysler product without large amounts of under-carpet padding and such and the 1970 Torsion-Quiet Ride items.

One main issue with the dual front I-beam suspension those pickups had on them is "sagging coil springs". When the front springs sag, with age and wear, the caster goes away and the camber gets out of whack, which is why the beams must be bent in many cases to get the adjustability back. I had a friend who ran a Firestone store for a good while. He said that rather than bend the beams, to just put "load leveler" shocks on the front. That would usually raise the front end to it was more like original, then.

Take care,
CBODY67
Well I did replace the front springs in my F-100 and found that the old springs were both the same size when, in reality, the springs are slightly different in height from the factory.

As to the Ford vs Chrysler when trying to put it into words I would say the Ford drives as though it is a heavier car yet both less than 100 lbs. apart.
 
I would stay away from the poly bushings all together. When I rebuilt mine about 15 years ago I used all rubber and it is still driving like a new car. I know of a few guys who used poly bushings and they were not happy with the results and the extra work it took to install them. Contact Craig @mobileparts and he can get you all of the components you need and they are of the higher quality older stock, not a lot of the imported junk you may get in a kit today. His prices are good and service is excellent. A lot of us here have dealt with him over the years. Good luck and keep us posted.
I saw him mentioned when diving into the archives for information. The actual work will be done early next year after the Parklane engine is finished. Both will never get their suspensions rebuilt again by me as I will be around 88-90 then but you never know.
 
The reason I would not put polyurethane bushings in the LCA is that eventually, they can fracture and break. Time, impacts, and similar. Any bushing or anything made of rubber or plastic, the oils in them will evaporate over time, which can degrade their location abilities.

With rubber, the rubber can visibly crack and "settle", but not break, as it ages and dries out. With the polyurethane sway bar link bolt grommets, over a long time, I have had to replace several of them that broke and disappeared, even the softer Moog ones.

On the Chrysler LCA bushings, if a polyurethane busing might fracture, it might be well-enough contained that the fracture would not result in a portion of the fractured item leaving its installed location. As this location is also related to the torsion bar adjustment, that might be something else to consider, to me.

When installing the poly link bolt grommets, I noticed that they would compress a bit, just as rubber will. But I also suspect this compression can be what can also make them fail if over-compressed for too long. In this case, splitting and leaving their location.

On the rear suspension, impact forces can be less than on a front components, to me. Forces would not be spiked, but forces reach their peak on a more gradual progression, than on the front end suspension. As the upper control arm bushings are about "location" and "pivot", that is why I would consider poly being better at that location than on any LCA location.

Just my thoughts,
CBODY67
 
I did the FirmFeel kit, full poly.
I have been worried that the poly was a mistake, but a few years later I have no problem with the ride and I haven't noticed squeaking. The advice that I followed that I believe helped was to liberally apply PTFE lubricant on the bushings.
 
Yep, my poly bushing came apart without grease or something on them. And they do age out just sitting in the car even if it's not driven. Give them enough time and they turn to something that resemble crayons. But I only tried one brand one time.
The new cars are stiffer and require more effort to drive and they do handle better. The old cars are softer and easier to drive. That's something the new cars can't do no matter what you do to them.
We're never going to make an old car handle like a new car and still be able to tolerate the car.
I think it makes sense to keep the smooth and easy driving experience just the way it came, except for tires, shocks and sometimes more sway control.
Other than that, I suggest driving an old car with a new altered stiff feeling steering box before installing one.
If the original box is 100 percent and everything else is tight and lined up to suit your taste it can be a great driving car just the way it was built.
If I drove the car once a month for a few miles each time I might feel different, but when I leave town for a few hundred miles I take an old car for the smooth relaxed feel, reduced driving effort and sofa seat.
As for interior noise? That's a whole different thing. I'm working on that.
 
1. Upgrading the power steering box is Ok.
I have the Stage II in my '70 300. It's good, especially on the highway, but if I did it all over, I would choose the Stage I. I see they offer 4 stages now, with Stage 0 for a stock rebuild. At the time, they just offered 3 stages.
 
I think years ago people did more parallel parking. Parking on the street, when there were more stores on streets and no shopping malls with mega parking lots and easy parking. Power steering was designed for parallel parking back then.
 
I think years ago people did more parallel parking. Parking on the street, when there were more stores on streets and no shopping malls with mega parking lots and easy parking. Power steering was designed for parallel parking back then.
I don't do parallel parking anywhere. If I did that would mean someone possible in front of me and behind me trying their hand at it with my car right there. Oh, no, and I spent 10 years in San Francisco with two them them parallel parking everyday till I had a garage. I've seen how others do it...
 
I spent several hours looking over the different parts and suppliers to rebuild my original front suspension and have a question. I already decided to get the Firm Feel Stage 1 power steering box. Also decided on their upper control arms so I have more control over alignment. After that there is the general suspension kit. Question is where should poly bushings be Ok and where should rubber bushings be best? This is generally a highway car so firmer steering (the new box) and a better sense of planted on the road for cruising. So not like my 2004 Focus ZTS but more like my 2004 Buick LeSabre in ride which isn't bad. Thinking of acquiring parts while I work on assembling my 410 and then switch out the big Merc for the big Dodge.
get the big torsion bars out of a very late C Body SW or PC much larger than the .92 that come stock in like 73 and earlier
get the rear sway off a Cordoba it is a bolt in
get some wide wheels
add a leaf in the back
good shocks
will handle like a sports car
 
I don't think the 47" bars were ever .92 inches. .94 is what I've read, and it's what I had in my '67 Canadian Monaco with 318 and no A/C. According to the parts books your typical slab (and probably fusey) C-body with 383 came with .96 bars, there might have been .98 bars for the slabs for heavy duty.
 
Rubber lends a soft, cushy feel, poly is firmer, more sporty. But poly can be too hard, on potholes & dirt roads, transmitting shocks, jolts and vibrations to other parts, leading to accelerated wear & tear.

Think long term: How long are you going to keep this car? Are you fixing it up to flip it and bank a buck? Is this your "retirement plan"? Something to pass on to your kids or grandkids? Are you willing to rebuild it again in 10-20 years from now, or do you want to squeeze out another 50 years out of it?

If long term reliability is key, go rubber.
If firm, tighter handling is your goal, poly is the answer.

You can't have both. You could mix and match, but remember, poly can be harder on other parts leading to more repairs & maintenance in the future.

Me, I went full poly. I'm building a hot rod out of my Newport. It IS my retirement plan. I've practically made a career out of building cars from the ground up, then driving them back into the ground. I LIKE sporty handling. Even if it does brake later, I expect that. It'll never outmaneuver a Porsche or a Viper, but I won't make it easy for them to shake me off their tail. And I'll be damned if I'm going to be humiliated by a Prius.

You make your choice, you pay your dues and you live with the consequences.
 
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