Frequently Asked Questions
Click the "+" sign to expand the question!
Customer Service
1. When we ship you the wrong part(s) or a part has a warranty issue what do you do? Do not pick up the phone and call us. Please click here and fill out our claim form. We will need you to send picture proof. You can attach the pictures to the claim form.
You will be sent a tracking number via email once your order has shipped. Please visit this page for more information on how to track your package.
Please understand that due to the pandemic and everyone having extra time to work on their Bronco we are experiencing delays on some items. This has caused several delays in shipping parts that are normally in stock and ready to ship. Some delays on orders can be up to 6-8 weeks on lift systems with multiple components. After placing your order you will be contacted by a salesman via email with an estimated shipping date if there is a delay. We appreciate your patience while we do our best to get your order expedited. Thanks for choosing James Duff!
If we have any active promotions or discounts they will be reflected on the item you are purchasing or automatically applied during checkout.
We do not have any coupon codes or discount codes.
We send out a monthly newsletter via email that will have our newest products or promotions that we are offering. If you are not subscribed to that newsletter you may do so here.
Yes, we do. When checking out your shipping option will present as shipping quote. This means after you place an order the order will go to our shipping team to find the most economical option to ship your parts and you will be sent a second invoice to collect funds for the shipment.
You can also contact us, to get a shipping quote before placing the order.
Please understand that shipping quotes and invoicing do take an additional 1-3 business days to process.
You may read our return policy located here.
Please check our product instructions page located here. You can download and print the same pdf instruction sheet that we package with our parts if yours is missing or has been misplaced.
If you requested a return and it's been processed and returned here is when you can expect the funds to arrive in your account from our Merchant Services provider, PayPal.
If you do request a refund and we have processed your return you should be aware of how that process works from our credit card processor, PayPal.
If you paid with your:
- Credit card (including PayPal Credit): your refund will go to your credit card. It may take up to 30 days for the refund amount to appear on your card statement. If the card was canceled or you paid with a prepaid card, contact the card issuer to access your refund. The money will still be sent to this card account.
- Bank account: your refund will initially go back to the PayPal balance before being auto swept back to the original funding source (bank). It may take up to 5 business days for the refund amount to appear on your bank account. If a refund is issued shortly after you paid, we'll try to cancel the transaction so you're never charged. If we're unable to cancel the transaction, the refund will be processed and sent to your bank account.
- PayPal Cash or PayPal Cash Plus balance: your refund will go to your PayPal Cash or PayPal Cash Plus balance on the same day the refund was processed.
- PayPal Cash or PayPal Cash Plus balance + credit card: your refund will go to both your PayPal Cash or PayPal Cash Plus balance and credit card. The refund to the balance will happen the same day it's processed; the refund to the card may take up to 30 days.
- Debit card: your refund will go to your debit card. It may take up to 30 days for the refund amount to appear on your card statement. If the refund can't be applied to your debit card, it'll be sent to your PayPal account.
James Duff Inc. takes great pride in building some of the most innovative & toughest parts in the industry and we stand behind our products with a warranty that covers defects in materials & workmanship.
We never like to hear that one of our parts has become damaged or defective, so as part of our returns process, we do a full review of the damaged/defective part in an effort to best determine the root cause of the damage and/or defect.
Our team will review your Returns Request information and provided pictures and if the damage or defect appears to be materials or workmanship related, then we will gladly offer a refund or no-cost part replacement.
However, if we determine the issue is not due to defective materials or workmanship, then the parts will not be covered by our warranty and a no-cost replacement will not be available.
For more information about our returns or warranty process or to submit a return please view our returns page here.
Yes, see this link. You can request a copy. Please keep in mind that pricing has changed since this was published and you will need to refer to the product page for the most up-to-date pricing.
We've found the best match for our Duff Blue is Rustoleum Painters Touch Paint and Primer in Deep Gloss Blue. It is available at most major retailers.
Frequently Asked Questions about Our Suspension...
Our radius arms are designed and engineered to work the factory-equipped Dana 30 or Dana 44 front axle on the Early Bronco Platform. They will also work in the Full-Width High Pinion Dana 44 that comes installed in the '76-'79 F-150 4x4 or '78-'79 Big Bronco. If you are wanting to pair them with another axle such as a Dana 60 or Super-Duty 60 then you must ensure that the axle uses the ford style axle wedges or you must grind off any brackets that use a different style attachment point and weld on the wedges we sell.
For straight axle vehicles, caster is a major part of the front-end alignment equation that makes your front axle and steering wheel track straight while driving. Without the right degree of caster, you are constantly correcting the steering wheel and have little to no confidence in your ability to control and enjoy your Bronco.
What is the right degree or the perfect amount of caster? It actually can depend on the tire size, lift size, and vehicle. Plus, on '66-'77 Broncos and pre-'76 F150 4x4's with factory low pinion Dana 44 front axles, too much caster can cause front driveline failure prematurely. With that being said, we shoot for a minimum of 3 positive degrees of caster in the front axle. High Pinion Dana 44 front axles can handle up to 3 degrees more positive caster but also do very well at a total of 3 degrees of positive caster.
Keep in mind, your front-end bushings, steering geometry, and toe-in also are important here.
NOTE: Arm geometry, ride control, and caster are all greatly affected by lifting a 66-79 Bronco & F150 4x4. Any lift over 3 inches for a 1st gen bronco and any lift over 4 inches for a 2nd gen Bronco and 66-79 F150 4x4 may require more caster correction than stock length aftermarket arms and C bushings. Extended radius arms, radius arm drop brackets & caster/camber correction bushings could be necessary to control your vehicle once lifted. Results will vary, see your alignment shop after you install the lift.
1966-77 Bronco with stock arms:
#6002 2° C Bushings, stock height
#6004 4° C Bushings, 1 – 2″ lift
#6007 7° C Bushings, 2.5″+ lift
NOTE: Any suspension lift over 2.5" on a 66-77 Bronco (factory equipped) may require radius arm drop brackets or aftermarket radius arms to achieve 3+ degrees of caster required for the vehicle to drive and steer with control at road speed.
1966-77 Bronco with our #5350 Long Travel Radius Arms with 4.25° caster built into the arms:
3.5″ lift: #6004 4° C Bushings
5.5″ lift: #6007 7° C Bushings
1966-77 Bronco with our #5355 T-Rex Arms Radius Arms with 4.25° caster built into the arms:
2.5″ lift: #6004 4° C Bushings
2.5″ lift: #6007 7° C Bushings with high angle drivelines
3.5″ lift: #6007 7° C Bushings
5.5″ lift: #6007 7° C Bushings
78-79 Bronco/F150 with our #5351 Long Travel Radius Arms with 4.25° built-in:
2-4″ lift: #6002 2° C Bushings
5-6″ lift: #6004 4° C Bushings
6″+ lift: #6007 7° C Bushings
78-79 Bronco/F150 with our #5355 T-Rex Radius Arms with 4.25° built-in:
2-4″ lift: #6002 2° C Bushings
5-6″ lift: #6004 4° C Bushings
6″+ lift: #6007 7° C Bushings
80-96 Bronco SAS with our #5353 Long Travel Radius Arms with 4.25° built-in:
Same as 78-79 Bronco with #5351 but they will vary depending on what degree the C-Wedges are welded onto the housing.
Bronco II & 83-97 Ranger Dana 44 SAS with our #5352 Long Travel Radius Arms:
3-4″ lift: #6004 4° C Bushings
5″+ lift: #6007 7° C Bushings
Purchase your C-Bushings here.
A performance-oriented suspension and a smooth ride-our progressive rate coils offer the best of both worlds. Our progressive coil as opposed to a stock single rate coil; the rate gradually increases as the coil compresses. The upper wraps are softer for a more comfortable street ride; the middle rates are a bit firmer to handle bumps and dips without jarring, and the last few wraps are a higher rate so that they control the up travel to prevent bottoming out.
Since the coils have a softer initial rate they also will deliver more suspension travel than a single rate coil. The softer rate allows the tires to stay on the ground; providing better traction and handling. The progressive nature of the spring also allows for better and more predictable handling by helping keep the vehicle flatter in the corners and limiting body lean.
Stock suspensions were designed primarily for improved road use and safety with little consideration for true off-roading. We know that our customers are outdoor adventurers who travel the back roads and beyond. We consider this type of use and on-road safety when designing our suspensions.
A suspension lift raises the frame and body from the differentials and wheels, allowing the use of larger tires which increases the ground clearance under the axles in order to clear trail obstacles. Attention to wheel travel and overall ride quality is an important consideration in the design of our suspension lifts. The improved traction and wheel travel directly translates into how well a vehicle will traverse any terrain. A vehicle properly equipped for off-road use causes less damage to our trails.
Our shocks are valved 70% rebound, 30% compression. With our suspension systems, our proprietary coil and leaf spring are designed and engineered so the shocks aren't needed for primary compression control. Our shocks smooth out the ride by predominantly controlling the rebound. They don't overheat because they aren't trying to control compression.
Conventional 50/50 valved shocks use equal pressure on both compression and extension. That creates a choppy ride, overheating shocks as they try to control compression instead of letting the spring do its job.
The only time we have seen 8 of our classic 70/30 shocks create a rough ride on a Bronco is when the Bronco had very few accessories on it or was a stock roadster(U13) or a half cab(U14). Even then it was not across the board rough for every Bronco since several other factors create a rough ride like overinflated tires, stock or worn-out seats, poorly installed suspension, other companies suspension combined with Duff shocks and sometimes it just comes down to personal preference.
The biggest misconception in the industry is that all off-the-shelf twin and monotube off-road shocks have the same 50/50 valving. At James Duff that couldn't be farther from the truth! We developed a shock over 30 years ago that lets our springs do their job and spends more time controlling the rebound. This is a large reason why you can run 8 Duff classic 70/30 shocks on your Bronco and experience a smooth ride. 8 shocks also help control body roll. Especially when lifting your Bronco over 3 inches.
Duff suspension components are designed, tested, and most, built in house. Our design team strives to build the highest quality parts while keeping the customer's budget in mind. Our components are built for easy installation using common hand tools and most of our products require little or no welding. Our suspension systems are predominantly built using the best American made materials available. Many of our parts are CNC laser cut and bent for quality and a precision fit. Our parts are formed and welded on-site by our fabrication specialists. Unlike others in the industry we use a premium durable powder coat or high luster zinc finish for longevity.
95% of Duff products will match some sort of factory mounting spot on the vehicle. This is usually to locate where a bracket goes. You will use the bracket as a template to drill the rest of the mounting holes in the vehicle. We also usually recommend welding the brackets into place or vice versa depending on what you have access to at the time. Please take into consideration that although we strive for proper fitment and build our products in fixtures for consistent accuracy, the majority of vehicles we are working on are over 30 years, some older than 45, there are going to be some inconsistencies from vehicle to vehicle. Please take this into consideration when installing, it may take a couple of hits with a big hammer for perfect fitment. 🙂
Dana 30 Front axles came on Early Broncos from '66 to '71.5 they are easily identified by looking at the top of the steering knuckle. If your axle has this cap with 4 bolts it is a Dana 30 Axle. Dana 30's used king pins to attach the knuckle to the axle.
Halfway through 1971, Ford upgraded the front axle to a Dana 44. To identify this axle you will again look at the top of the steering knuckle. There will be a ball joint with one single castle nut attaching it to the threads on top of the ball joint. If yours has a balljoint it is a Dana 44.
See the photo below...
No, we do not offer the piece that goes between the arm and the axle as a stand-alone part.
Now, set up your rear axle where you want your wheel base to be. A couple of plumb bobs are your friend here. Set the axle at the same height as the front axle. Set the axle so the pinion angle is tilted up between 13-15 degrees then square the axle housing up to the frame, tack weld or bolt the truss onto the axle and assemble the links. Attach the links to the frame brackets and with a helper, install the frame brackets to the frame with a couple of giant c clamps then adjust the link lengths until they bolt to the truss.
The pinion angle is a general guideline for stock EB driveline configurations and could change depending on what drivetrain you choose.
Now the location for the coil buckets presents itself once the 5120 lower coil retainers are installed to the truss. Use plumb bobs here as well to make sure the coil buckets are centered on the lower coil retainers. Tack weld the buckets so the bottom of the bucket is flush with the bottom of the frame. I don't recommend fully welding the buckets onto the frame until you have got the entire Bronco complete so make the welds a heavy tack.
Use our install instructions below if you have any further questions about the install.
Frequently Asked Questions about the Early Bronco Platform...
Before you choose your spring, you need to understand the difference between Medium duty and Heavy duty. First off the difference has nothing to do with ride quality. Our Heavy Duty spring will not give your Bronco a stiffer ride. This is simply to make sure your Bronco will sit level or at the very least not squat in the back when your Bronco is complete.
Medium-Duty springs are for 66-77 Broncos that have very few add-ons or accessories in the rear. For example, if you have a stock half cab or roadster you would choose medium duty. If you have a resto-mod wagon with a soft top, stock rear bumper, no spare tire, and stock fuel tank, with or without a back seat but not typically using it, then you also would choose medium duty springs. We do NOT recommend medium duty for trailer towing.
Heavy-Duty springs are for 66-77 Broncos that are geared more towards a well-equipped resto-mod for on and off-road use. If you have or plan on upgrading to a 20+ gallon rear fuel tank, tire carrier + tire, steel plate rear bumper, and/or want to run a hardtop, the heavy-duty leaf spring is also a great choice for your build. These are also the best option if you plan on ever towing anything with the Bronco. If you like going off-road and hitting the trails, the heavy-duty leaf springs are typically the best option for you as well.
For some of you, there will be some combination of parts that accessorize your Bronco in between a soft, medium, heavy, and extra heavy-duty setup. This is why we offer lifted spring perches, 1/2" and 1" lift blocks as well as pinion shims for driveshaft angle corrections to get your ride height and driveability spot on. Our new 1/2" lift block will also offer the option to move the axle back for that perfect amount of tire to fender clearance for the uncut lifted 66-77 Broncos.
Installation Note: The Double spring Wrap aka Military wrap is to be installed towards the front of the vehicle.
You can also add on great upgrades when purchasing these springs like Leaf spring and shackle mounting hardware, Shackle bushings, the Duff HD spring plates, U bolts or HD U- bolts (both that come standard with new HD hardware), HD shackles, pinion shims, lift blocks and new Duff HD weld on spring perches offered in factory and 1" built-in lift.
| Lift Height | Fenders | Max. Rec. Tire Size |
|---|---|---|
| Stock | Uncut | P205/70R15 |
| Flares | 31 x 10.50" | |
| 2.5" Suspension | Uncut | 32 x 9.50" |
| Flares | 33 x 12.50" | |
| 2.5" Lift + 1" BL | Uncut | 33 x 9.50" |
| Flares* | 35 x 12.50" | |
| 3.5" Suspension | Uncut | 33 x 9.50" |
| Flares* | 33 x 12.50" | |
| 3.5" Lift + 1" BL | Flares | 35 x 12.50" |
| 3.5"+2" BL | Flares | 35 x 12.50" |
| 5.5" Suspension | Flares | 35 x 12.50" |
| 5.5"+1" Body lift | Flares | 36 x 12.50" |
| 5.5"+2" Body lift | Flares | 37x12.50" |
Notes: Tire size can vary depending on wheel offset, wheel width, and tire tread design. These sizes are based on a 15x8 wheel with 3.5" backspace. These tire sizes are a general guideline because a wider tire or offset rim can cause interference with the sheet metal. A large lugged mud tire will also require more clearance or a shorter overall height in order to clear compared to an All-Terrain tread style.
*3.5" lift with no body lift we recommend not going over 33" tires because the lift is all suspension. *If it was 2.5" of lift and 1" of body lift we would recommend 35" tires with minimal cutting to the body.
A 2" body lift will generally allow a 1.5" to 2" taller and wider tire to be used. For even more clearance our fender flares can be added and the sheet metal trimmed to clear the tires.
It is now! Traditionally, we would have told you no. Our first design was built with extreme rock crawling in mind but as the value of the Early Bronco increased, many customers weren't willing to beat them up. We evolved with our customer and now offer a Dual Sport 4 link that is specifically tailored to the Bronco enthusiast that wants the ride and control a 4 link offers without the body roll our extreme setup has.
Another great offering is our 4 link sway bar. Pair it with the Dual sport 4 link to enjoy many years of high and low-speed adventures!
From '66 to halfway through the production year of '77 Ford used a banjo style rear axle housing for their 9" axle. During the production change in '77.5, Ford used a unique axle for the remainder of the production, known as the centurion axle. For the factory centurion, the third member is offset to one side.
This is important knowledge when shopping for our 4-Link Systems as you'll need a truss that is correct for your rear housing. Otherwise, the truss will not fit.
We have found that regardless of the year of the Bronco you should check this when purchasing a 4 link, as we've seen customers Broncos that have late model front and rear axles installed in their earlier year model Bronco.
This is also important when installing the rear Hellwig sway bar, as you'll need longer u-bolts to accommodate the larger axle tubes.
Yes, we believe you should. Whether you're on or off-road, the heim steering setup is a proven design that will get you to and from the grocery store or the trail and several thousand miles in between.
In fact, the heim steer system is an intrical component of our wildly popular BS eliminator kits. If it concerns you, check your local laws to see if there are any restrictions to using a heim steer kit.
95% of Duff products will match some sort of factory mounting spot on the vehicle. This is usually to locate where a bracket goes. You will use the bracket as a template to drill the rest of the mounting holes in the vehicle. We also usually recommend welding the brackets into place or vice versa depending on what you have access to at the time. Please take into consideration that although we strive for proper fitment and build our products in fixtures for consistent accuracy, the majority of vehicles we are working on are over 30 years, some older than 45, there are going to be some inconsistencies from vehicle to vehicle. Please take this into consideration when installing, it may take a couple of hits with a big hammer for perfect fitment. 🙂
Frequently Asked Questions about the '80-'96 Bronco Platform...
Long arm frame brackets from the rear of A-pillar body mount flange to front leading edge of long arm frame bracket - 13” BOTH SIDES see photos. These measurements are based on our '96 Bronco you will need to measure and make sure your axle is where you want it. Always triple check before making anything permanent
5110 Duff Coil bucket placement - hook tape measure to the back edge of the front body mount and measure back 15 1/2” - BOTH SIDES
5110 Duff coil bucket height from the bottom of the frame to the landing pad/seat for the top of the coil spring is 9.5” for a 6” lift - BOTH SIDES
See photos. These measurements are based of our '96 Bronco you will need to measure and make sure your axle is where you want it. Always triple-check before making anything permanent.
If you have removed the TTB and swapped in a solid axle, Yes, we believe you should. Whether you're on or off-road, the heim steering setup is a proven design that will get you to and from the grocery store or the trail and several thousand miles in between.
If it concerns you, check your local laws to see if there are any restrictions to using a heim steer kit.
If you have a '94-'96 FSB and/or an E40d transmission you will need to modify or replace the factory cross-member with a custom-made cross member. James Duff does not make this part. Here are picture examples of what it can look like if you build a custom cross-member.
If you are installing a Torque Tamer on a '90-'96 Bronco and it is equipped with an electronic shift on the fly servo as shown in the pictures below. It will be required for you to install the torque tamer with the main bar attached below the cross-member.
Frequently Asked Questions about the Ranger/Bronco II Platform...
No - The coil buckets are placed differently on the frame and won't allow the vehicle to sit at the correct static height. If you are wanting to convert from 2wd to 4wd we do not have an extensive knowledge base on what is needed to convert your vehicle. For more information, we suggest you visit a community forum related to your application. If you are wanting to convert to a solid axle swap system please see our SAS swap list.
You will need to source an axle with wedges to utilize our solid axle swap parts. We have seen customers use an Early Bronco width Dana 44 or a Full-Width Dana 44. Please check with a community forum for suggestions on what axle is best for a solid axle conversion.
- 5352
- 5410
- 5402
- 5640C
- Knuckle mounting kit
- 6002, 6004, 6007
- 5261 - not required but gets you double shocks
- 5340 - if not using a Dana 44
- 5351-HP44 - High Pinion Dana 44 axle only
- 5341 - Optional
- 5301 - Optional
- 5112 - if going to full width or 1 ton axles
- 5406 - If going TRO
- 3" and 5" leaf springs for RBV
- Early Bronco coil springs 2.5 to 5.5 - customer will choose
- Drop shackles
- Spring hangers
- weld on axle perches 5934 - 5935
- U bolts - 5920 or 5926
- Shocks - Customer will need to choose and measure
We suggest you check out our ranger v8 post here. This will outline most of the parts required. Keep in mind we are currently out of stock on our radiator and v8 swap headers. We do not currently have an ETA on when those parts will be available. You can search for these parts using Google.
| Bronco II & 83-92 Ranger | Tire | Flares/Trim |
|---|---|---|
| 2.5-3" Suspension | 31"x10.5" | Not Required |
| 32"x11.5" | Flares/ May Need Trimming | |
| 2.5-3" Suspension | 32"x11.5" | Not Required |
| +2"body | 33"x12.5" | Flares/May Need Trimming |
| 2.5-3" Suspension | 32"x11.5" | Not Required |
| +3"body | 33"x12.5" | Flares/May Need Trimming |
| 4-6" Suspension | 33"x11.5" | Not Required |
| 35"x12.5" | Flares/May Need Trimming | |
| 4-6" Suspension | 32"x11.5" | Not Required |
| +2-3"body | 33"x12.5" | Flares/May Need Trimming |
| 4-6" Suspension | 33"x11.5" | Not Required |
| +3"body | 35"x12.5" | Flares/May Need Trimming |
| 93-97 Ranger | Tire | Flares/Trim |
|---|---|---|
| 2.5 -3" Suspension | 32"x11.5" | Not Required |
| 2.5-3" Suspension +2-3"body lift |
33"x12.5" | Flares/May Need Trimming |
| 4-6" Suspension | 32"x11.5" | Not Required |
| 33"x12.5" | Fender Trimming | |
| 4-6" Suspension +2-3"body lift |
35"x12.5" | Flares & Trimming |
Notes: Tire size can vary depending on wheel offset, wheel width, and tire tread design. These sizes are based on a 15x8 wheel with 3.5" backspace. These tire sizes are a general guideline because a wider tire or offset rim can cause interference with the sheet metal. A large lugged mud tire will also require more clearance or a shorter overall height in order to clear compared to an All-Terrain tread style. A 2" body lift will generally allow a 1.5" to 2" taller and wider tire to be used. For even more clearance our fender flares can be added and the sheet metal trimmed to clear the tires. Keep in mind that installing taller tires may require a ring and pinion gear change or the addition of performance add-ons for the engine or both modifications. On models up to 1989, we highly recommend upgrading to stronger later model axles when more horsepower and bigger tires are combined. Larger tires will also affect the ratio that the speedometer reads and thereby may show a slower speed than actual speed.
No. Our BII/Ranger suspension systems are available in stages. To prevent our coil springs and TTB axle brackets to be mixed and matched with other supplier's parts. Too many times in the past we would attempt to tech a customer's ride or warranty an issue only to find out the issue was from not using our complete systems.
Each of our kits is tested individually, then tested again with each of the upgrades available. The suspension components are matched with one another to provide the best overall performance. This is of the utmost importance in the Twin Traction Beam suspensions. All of the components must be addressed when lifting, otherwise, the vehicle will have serious handling and alignment issues. Most components are only available kit form in order to address these issues. This assures you of a great performing suspension system, having all of the components work together.
If your Ranger or BII has been solid axle swapped. Yes, we believe you should. Whether you're on or off-road, the heim steering setup is a proven design that will get you to and from the grocery store or the trail and several thousand miles in between.
If it concerns you, check your local laws to see if there are any restrictions to using a heim steer kit.