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1975 Ride Improvement

SamD

Full Member
Joined
Feb 25, 2014
Messages
214
I recently replaced all 4 shocks on my 1975, but the ride still feels "wallowy". I'm not looking for a hard ride, but something with a lot less wallow / sway would be great.

The Bronco only has 30k original miles, and up until I installed new Bilstein's on all 4 corners, the suspension was completely original.

This Bronco is my daily driver and is almost never off road.

Are new variable rate springs front springs the answer? Should I change the lead springs as well?

Thanks

Sam


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Digger556

Sr. Member
Joined
Aug 8, 2013
Messages
793
I recently replaced all 4 shocks on my 1975, but the ride still feels "wallowy". I'm not looking for a hard ride, but something with a lot less wallow / sway would be great.

The Bronco only has 30k original miles, and up until I installed new Bilstein's on all 4 corners, the suspension was completely original.

This Bronco is my daily driver and is almost never off road.

Are new variable rate springs front springs the answer? Should I change the lead springs as well?

Thanks

Sam




Sent from my iPhone using Tapatalk



You'll need stiffer springs. Normally I don't advocate this, as many aftermarket springs are too stiff. However I have seen some numbers for factory springs indicating rates as low as 160lb/in. That will generate soft feel when compared to the sportier suspensions of modern cars. You could step up to a 170-180 lb/in springs (for the front) and ~200lb/in rear and be okay. Just don't buy stiff springs to solve body roll while cornering, that's what sway bars are for.
 

jagbucket

Full Member
Joined
Aug 9, 2013
Messages
251
almost a shame to drive it on a daily basis you should get another daily driver and preserve that one. But also there is a sway bar kit for it as you see limited off road and its a bolt on. . As you remove those original parts keep them it will increase the value when and if you resale. hope you kept the original shocks. Im also working on a big block mustang and the original shocks are gold in any condition.
 
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SamD

SamD

Full Member
Joined
Feb 25, 2014
Messages
214
almost a shame to drive it on a daily basis you should get another daily driver and preserve that one. But also there is a sway bar kit for it as you see limited off road and its a bolt on. . As you remove those original parts keep them it will increase the value when and if you resale. hope you kept the original shocks. Im also working on a big block mustang and the original shocks are gold in any condition.



I may try the sway bars first.

When I say "daily driver" that doesn't mean it gets many miles. I travel at least 50% of the time, -"and work from home when on not on the road so i only really drive it on the weekends.

Sam


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SamD

SamD

Full Member
Joined
Feb 25, 2014
Messages
214
You'll need stiffer springs. Normally I don't advocate this, as many aftermarket springs are too stiff. However I have seen some numbers for factory springs indicating rates as low as 160lb/in. That will generate soft feel when compared to the sportier suspensions of modern cars. You could step up to a 170-180 lb/in springs (for the front) and ~200lb/in rear and be okay. Just don't buy stiff springs to solve body roll while cornering, that's what sway bars are for.



I think what I'm feeling may be body roll. It doesn't just happen when I'm cornering, but also when I'm changing lanes or just course correcting.

Sam


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Pa PITT

Contributor
Bronco Guru
Joined
Jul 15, 2005
Messages
11,252
Loc.
Stephenville TEXAS
.. I was going to say add Sway Bars to it...
.............
... I'm an old fart as you can tell by my number of post. But I once built a 440 Dodge truck. As a pull truck. It was all 1/2 ton up front & 3/4 ton on it's flat bed in the back.
1975 model I think. It rolled & twisted until I had to round corners at 55 mph. Not what I built it to do.
So, Some where in here I bought a 1/2 ton camper special. It had front & rear sway bars under it. I pulled them & bought about $20.00 worth of Bushing & added these bars to my new toy hauler. HOLLY CRAP .. I Could sail thru the same corners at about 85 mph.
... Honest to GOD.. Those sway bars improved my truck, More than anything else I ever did to it.
.. & Also ever since, every next ride I've built .. I've always, even on the 1st drive I've ask myself, Will this need SWAY BARS.
 

blubuckaroo

Grease Monkey
Joined
Jun 11, 2007
Messages
11,795
Loc.
Ridgefield WA
New springs.
You need new springs. Even if your car's mileage is really 30K, or 130K, or even 230K, the car has been hanging on those springs for over 40 years. They get squishier with time.
I've found the new spring 10-11 leaf rear spring packs and variable coil front springs ride a lot better. However that ride comes at the cost of a squishy ride. (again)
While the old five leaf setup was rougher riding, it handled a lot better.
Since the high leaf/variable rate route or vendor have taken, sway bars are the only answer.
Imagine that.%)
 

Broncobowsher

Total hack
Joined
Jun 4, 2002
Messages
34,835
Also, what are your tires and tire pressures?

Sway bar(s) are probably going to be a good solution without getting into a harsh ride.
 

jckkys

Bronco Guru
Joined
Mar 15, 2012
Messages
5,196
There were GVW packages from 4300 lbs. to 4900 lbs. at least 4 in total. All were "stock". The front coils came with 2 rates or capacities. There were two different rear leafs too. In my experience the front springs in the 4600 and 4900 GVW packages were far too weak in relation to the rear springs. Ford wanted a soft ride with a pickup truck load carrying capacity. The end result of this contradiction is poor handling and a nose down stance. The front end also bottoms out far too easily. I was able to fix these problems with '78-'79 Bronco F150 4X4 front coils for 20 bucks at the junk yard. A set of Rancho 5000 shocks complete the fix. My EB rides better than my wife's new Escape. A set of Helwig front and rear anti-sway bars fix the cornering lean. I was able to use the '76-'77 front anti-sway bar with the Helwig rear bar. I'll take this setup over any lift kit for both on and off road operation.
 
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SamD

SamD

Full Member
Joined
Feb 25, 2014
Messages
214
There were GVW packages from 4300 lbs. to 4900 lbs. at least 4 in total. All were "stock". The front coils came with 2 rates or capacities. There were two different rear leafs too. In my experience the front springs in the 4600 and 4900 GVW packages were far too weak in relation to the rear springs. Ford wanted a soft ride with a pickup truck load carrying capacity. The end result of this contradiction is poor handling and a nose down stance. The front end also bottoms out far too easily. I was able to fix these problems with '78-'79 Bronco F150 4X4 front coils for 20 bucks at the junk yard. A set of Rancho 5000 shocks complete the fix. My EB rides better than my wife's new Escape. A set of Helwig front and rear anti-sway bars fix the cornering lean. I was able to use the '76-'77 front anti-sway bar with the Helwig rear bar. I'll take this setup over any lift kit for both on and off road operation.



This one is a 4500 LB GVW.


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Lawndart

Sr. Member
Joined
Nov 23, 2014
Messages
836
Loc.
66030
I have an original Bronco swaybar set; bolts on without modification. If you are interested in going in that direction, pop me a PM.
 

SteveL

Huge chevy guy
Joined
Jun 24, 2001
Messages
11,613
Loc.
Hawthorne ca
What model bilstiens did you put on it? I put a set of 5100s on my 72 suburban 4x4 and they're too soft up front. I get quit a bit more sway than with the old wore out shocks I took off.
 

blubuckaroo

Grease Monkey
Joined
Jun 11, 2007
Messages
11,795
Loc.
Ridgefield WA
This may sound crazy, but I have used the Bilstein shocks from one of our vendors. I ended up pulling them back off and replacing them with the same model 70/30 Duffs shocks I had before.
I found the Bilsteins just too squishy.
The brand doesn't matter at all for me. I paint all the shocks black anyway. I just prefer the ride and control of the 70/30s.
 

jckkys

Bronco Guru
Joined
Mar 15, 2012
Messages
5,196
I agree, shocks should be black. The Rancho 5000s are inexpensive and last me 15-20 yrs. The ride is controlled but not stiff. The 9000s are very stiff when put near the stiffest settings. Both have more damping on compression than rebound. i don't know if they're 70/30 like Duff shocks. The lower settings on 9000s are like the less expensive 5000s. The '78 Bronco front springs are about 300 lbs/in. the rear '77 4900 GVW springs are about 250lb/in. The front end weighs more so this works well. It's no stiffer than new SUVs in the 3500-4000 lb. range where EBs live. I had to load the rear end with known weight and measure the deflection to find the rate. It's not published by Ford.
The '76-'77 front sway bar requires a bracket that's welded to all front axles in those years and square holes in the radius arms, also found in all '76-'77s.
 

ntsqd

heratic car camper
Joined
Jan 30, 2005
Messages
3,229
Loc.
Upper SoKA
That's a good data point on rear spring rate, but that is really wheel rate not spring rate and it is specific to that particular truck. Age of the spring and where the start and end measuring points were relative to the spring's total range of motion (starting & ending shackle angles) will all factor into the spring rate. So will if it is a tension type shackle (stock) or a compression type shackle ("shackle flip kit").

The singular best thing I ever did to a truck with 4 leaf springs under it was dump the Rancho shocks and put Bilstiens on it. That said, some folks find the damping rate of the front application Bils shocks to be too bouncy in coil spring applications. In their 2" bodied shocks (5100 & 7100 series) the upper limit in damping is not going to be enough for these folks and running at that limit risks bending the damper's shaft if you hit a big enough bump too hard.

The solution is either to go to a 2.5" bodied damper or go with dual fronts. I went with 2.5's, but I do not have them in place yet.
 

ntsqd

heratic car camper
Joined
Jan 30, 2005
Messages
3,229
Loc.
Upper SoKA
I went with Fox 2.5's, partly because of a hook-up and partly because a couple vet desert racers I've chased for like them better than Bils. Though with Fox's recent move to over-seas production I'm not sure that they still do.

Lee @ Raceshock.com has the valving for Fox 2.0's used on the front of EB's figured out. Fox 2.0's also have a larger diameter shaft than do the Bils, so the stiffer valve stack isn't a worry. They're not in the same price range a Rancho, but they are a far, far better damper.
 

jckkys

Bronco Guru
Joined
Mar 15, 2012
Messages
5,196
The wheel rate IS the spring rate on a live axle. One inch deflection of both wheels means one inch deflection of the springs. Obviously compressing one wheel a given value won't equal the compression of either spring over that axle. On a knee action suspension, it's usually about 2 to 1 wheel to spring movement, but not always. If you know a better way to measure rear spring rate or if you've found the factory specs for the rear spring rate, I wish you would share it. My method works until there's a better way. Single Rancho 5000s have worked well front and rear for 44 yrs. on 3 Broncos. Duel shocks were a waste when they were popular and they are still a waste. A buddy bought into the duel shock hype and his Bronco rode like crap. Heavy oversize tires hurt ride quality too. What do have for tires?
 
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