Project Big White: Suspension Upgrade on a 1995 Ford F-350
Ride Revival: Making the Suspension on Our ’95 Ford F-350 Function and Feel like New Again
The ’92-to’97 OBS Ford F-250/F-350 is a very popular rig among Ford diesel enthusiasts. Some die-hard fans actually consider the OBS pickup equipped with 7.3L Power Stroke engine to be the best Ford platform and powertrain ever. Even though many of these beasts are more than 20 years old, they are still very mechanically sound. However, those years of use—and, in some instances, abuse—have an impact on the handling and solid feel the trucks once had.
While many drivers may consider the sway and slop part of a truck’s personality and not pay too much attention to the degraded handling because the truck is driven on a daily basis, the truth is, the deterioration of suspension pieces makes using a bit more finesse while driving necessary to keep these trucks between the lines on the highway.
Even when maintenance and repair schedules are diligently adhered to, some areas of the suspension may remain untouched until there is a major problem. The rubber bushings, for example, can wear and severely break down over time, yet still look good to the naked eye. In certain parts of the country, the deterioration of bushings is more accelerated than others due to harsh weather and road conditions. Most people will replace individual or groups of bushings as they go bad. But, going through the entire truck and replacing all the suspension and sway-bar bushings can make it handle like a new truck (or possibly better than new).
Big White, Diesel Power Editor KJ Jones’ ’95 Ford F-350, is like many trucks of the era. The years of use have caused all the bushings to show their age. The truck has generally imprecise steering, with sway and body roll through the turns. To correct this, we took the truck down to Energy Suspension in San Clemente, California, and replaced all the compromised rubber suspension and sway bar bushings with new polyurethane pieces.
Energy Suspension is a leader in polyurethane chassis components. The company produces suspension pivots, motor mounts, isolators, and body bushings, and engineers are continually developing new polyurethane applications, as well as updating and revising older parts.
Ben LaHatt and Billy Ray Harrill in Energy Suspension’s new product department are taking on the task of revitalizing Big White’s suspension. Part of the replacement includes using the F-350 to develop new bushing kits for the ’92-to-’97 body style. Due to these trucks’ old age, the bushings and hardware are typically quite deteriorated.
The result of Ben and Billy Ray’s work is amazing. Polyurethane gives the 21-year-old truck a new vitality in the turns and a confident feeling at the steering wheel. The constant adjustments and compensations that needed to be made are gone. There is also less suspension and road noise when driving on the highway.
Read on through the following photos and captions, which detail the entire bushing-replacement process.
1. Here is a sampling of some of the bushings that are used for Big White’s chassis upgrade. Ben and Billy Ray are pulling from this assortment and taking detailed notes on which pieces they use.
2. The truck’s rear leaf spring bushings are original. Notice the spring is no longer centered on the bushing.
3. The frame is jacked up to unload the suspension. Before unbolting and removing the springs, all the hardware is sprayed down with penetrating oil to make removal easier.
4. Ben and Billy Ray work together to remove the hardware that holds the leaf spring on the axle and in the spring hanger. It should be noted that the axle is supported with a jack, and the leaf springs are removed one at a time, which makes reassembly much easier.
5. These photos detail how badly deteriorated the leaf-spring bushings are and how they are not centered in the spring any longer.
6. Billy Ray and Ben use a large shop press to remove the old spring bushings.
7. Once the old bushings are removed from the spring, the new polyurethane bushings are coated with Energy Suspension’s Formula 5 lubricant and installed in the eye. Formula 5 makes installation easier and prevents the bushing from squeaking. With the bushings in, the steel center sleeve is pressed into place with big locking pliers.
8. After lubing the spring hangers, Billy Ray reinstalls the leaf packs and tightens all the hardware to specification.
9. From years of carrying heavy loads, the pads the overload springs rest against on spring compression are badly worn. Billy Ray replaces the worn pads with new polyurethane pieces.
10. The rear sway bar and its links are removed and replaced with Energy Suspension’s polyurethane parts. Notice how collapsed and distorted the original rubber bushings are.
11. To replace bushings on a twin I-beam front suspension, the coil springs need to be removed (to relieve any stored energy and allow access to all the bushings). In order to give the I-beams more range of motion, the front sway bar links are removed first, then the coil spring is compressed and taken out. The front shocks are also unbolted from the I-beam trailing arm. Billy Ray uses a spring compressor that grabs the outside of the coil to compress and remove it.
12. When replacing the I-beam bushing, the retaining bolt needs to be extracted so the beam can be lowered. Notice the split in the original rubber I-beam bushing. The pivot bushing is actually bonded to the beam, so a sharp tool and some WD-40 are used to break them apart. Once the bushing is removed, a torch is used to release the remaining rubber that’s stuck in the socket. Once everything is cleaned, the new red bushing is pressed into place.
13. While the I-beam pivots are loose, the trailing arms can be moved far enough out of the pivots to change the bushing.
14. The trailing-arm pivot bushing shows major signs of wear. The bracket the bushing sits in has cut into it, causing movement that is transmitted through the steering wheel.
15. The bolt on the left with the galled threads is the factory I-beam pivot-bushing bolt. The galling was caused by the abnormal movement of the worn-out rubber bushing. Hardware should always be checked for damage and replaced as needed. The bolt on the right is the new replacement.
16. Here is Big White’s front end, reassembled with new polyurethane bushings that replace the old, worn-out rubber bushings. The upgrade gives the suspension new life.
17. This is an example of the condition of our project truck’s body mounts after 150,000 miles and 21 years of use.
18. On an old-school Ford F-350, finding all the body mounts and accessing them from the top takes a few minutes. Two are located in the engine bay at the core support (in front of the batteries). The top halves of the other four mounts are found inside the cab. The cab has to be cleaned out and the carpet pulled back to access them.
19. The stock isolator mounting bolts are removed. The two mounts under the cab use a press-fit nut/washer/sleeve combination to hold things together. Ben uses an impact gun with a puller attachment to separate the hardware.
20. The body is lifted and supported by bottle jacks in order to change the isolators between the cab and frame. Working on one side at a time enables the cab to remain in position.
21. In this comparative photo, polyurethane isolators are laid out along with all the Grade 8 hardware that is being used for the upgrade. As you can see, there is a significant difference between the original rubber parts and stock fasteners and the new replacements.
22. The new isolators are mock installed first to confirm proper fitment in every area. If an isolator does not properly support the load from the body, the bushing is trimmed. Billy Ray uses a custom-built polyurethane lathe to trim the isolators.
23. All the new body isolators were installed and torqued to specifications.
24. There is definitely a significant before-and-after difference between the cab and bed positions, with the original rubber isolators and Energy Suspension’s new polyurethane pieces. The rubber allowed the cab to sag while the new isolators bring the cab back up to its standard height.
What About the Body Mounts?
While Big White was at Energy Suspension, Ben LaHatt and Billy Ray Harrill took the opportunity to use the truck as a testbed for the development of a new body mount isolator kit for ’92-to-’97 Ford F-350s.
Just as they did with the suspension’s bushings, the truck’s age and mileage (150,000) have also taken their toll on the body mounts, making Big White a prime candidate for body-mount replacement. So, the truck’s cab mounts were disassembled and removed, allowing Billy Ray and Ben to take measurements of the bushings and hardware to ensure the body will be properly aligned once new bushings are installed. After everything was measured and documented, the truck was reassembled with the original parts.
Once the prototype cab and bed isolators were developed, we returned to Energy’s headquarters for the final stage of Big White’s chassis improvement. The last installation required only minor adjustments be made to the isolators and hardware pieces for proper fitment, and the notes taken during this process will allow Energy Suspension to build a final product that fits perfectly.
The combination of the new suspension bushings and body isolators definitely give Big White a rock-solid feel on the highway.
Energy SuspensionSan Clemente, 92673