TRU…TRO…If your Bronco is a handful to drive and you want to fix it, you probably have seen others throw these 3 letter acronyms around. But what do they really mean and how important are they? TRU stands for tie rod under. This means your tie rod mounts below or under the knuckle. TRO stands for Tie Rod Over & mounts above the knuckle.
Why is this important? 2 major reasons. Steering geometry and to keep your steering linkage up high away from trail obstacles. Steering geometry is critical to set up correctly to remove the dreaded bump steer that is quite common when lifting a Bronco. Just remember, don’t be dead set on TRU vs TRO. Either option can be good or bad for your bronco depending on how it is set up.
Honestly, there are so many options and ways to replace the steering linkage in a Bronco that it can be difficult to choose what’s right for you. Keep in mind all of this tech applies to solid axle Broncos, but is most prominent for Early Broncos.
- Factory style replacement or aftermarket?
- Tie rod ends or heims?
- T-linkage vs Y-linkage?
- Saddle vs no saddle?
- Off the shelf vs DIY?
- Standard vs Heavy-Duty
- TRU vs TRO?
So many ways to do this and it almost seems like there is no wrong way but what is the best way for YOU?
Luckily James Duff has taken most of the guesswork out of the decision by offering a Heim steer system that checks all the right boxes. All you have to decide is if you want to install it TRU or TRO. To make this decision correctly it comes down to a few things.
- What knuckles are on your front axle
- How much suspension lift do you have?
- Are you off-roading the Bronco?
First, let’s discuss knuckles. If you are going to use Knuckles from a Dana 30 or Dana 44 (with Drum brake knuckles) I would recommend only using these knuckles with 33″ or smaller tires. Also, remember that as you increase your wheel diameter that can also increase your stopping distance. With these knuckles, I just mentioned you can do some light off-roading but if you really want a knuckle that can handle abuse, more challenging trails, and bigger tire sizes then it is time to look at the Ford disc brake knuckles James Duff offers.
If you plan on running 35-37″ tires, first upgrade to Duff knuckles which also upgrade your brakes and will allow for larger axle u-joints to be installed. I recommend installing the BS eliminator system with these knuckles which will mount your tie rod on top or over the knuckle. If you already have 76-79 Bronco or F150 Knuckles then you do not need to upgrade to James Duff knuckles unless you just want the best and strongest of all disc brake systems offered.
Remember: Attaching the tie rod TRO requires the factory knuckles to be drilled out where the tie rod attaches to the knuckle since the attachment hole in the knuckle is tapered and the taper favors mounting the tie rod under the knuckle. Drilling is not required on the Duff Knuckles and the mounting kit is considerably less cost.
Second, suspension lift, If you have less than 3″ of suspension you can choose TRU or TRO. Which way gives you the best drive and control? Hands down TRO. Any suspension lift over 3″ I recommend going straight to a TRO setup. If you want to stay TRU with 3+ inches of suspension then you will need to install a drop pitman arm and a drop track bar bracket. Just keep in mind the only advantage to TRU is you do not need to drill out your factory knuckles. You still have to deal with steeper drag link and track bar angles (more bump steer) and more stress on your steering gearbox and track bar drop bracket at the frame. Plus you won’t want to go offroad unless it is a gravel road or mild trail. Don’t forget, track bar drop brackets require welding to be installed correctly. Whichever way you decide to go, if you want to change again from TRU to TRO (or vice versa) at a later date you will need to get another alignment done.
With over 3″ of suspension on a 33″ tire and the 66-75 knuckle, the tie rod can be installed TRU or TRO but I recommend it is installed TRO with a track bar axle riser bracket and no drop pitman arm or drop track bar frame bracket. Setting up your steering this way will eliminate bad bump steer and normal bump steer. This will require you to drill out the knuckle. You can install the tie rod TRU but if you don’t like how it drives you may need to get another alignment after you change it to TRO.
As soon as you go to a 35″ or bigger tire I always recommend taking your ’66-’75 knuckles off the Bronco and upgrading to the Duff knuckles and brakes. The smaller knuckles strain to support the larger tires and I have proven that the smaller drum style knuckles just can’t support the correct brake package to stop the Bronco quickly and safely. Plus, the bigger knuckles can handle bigger axle u-joints and the brakes are all Ford components that you can find at any auto parts store. Which of course that gets me talking about the T-bird caliper upgrade and Duff’s Hydroboost braking systems. But that is for another day 🙂
Third, are you off-roading the Bronco? If yes and you know you are going to push your front axle over large obstacles, then I always recommend mounting the steering linkage tie rod over, TRO.
Some of you may be trying to remove aftermarket parts from your Bronco and hope to install James Duff products. There may be a few challenges here to work around so let us know what you are starting with if you don’t see a solution for your current setup when ordering parts.
That wraps it up for this month’s edition of Tech Corner! Please leave us a comment below if you have questions or need suggestions on what system is right for your setup. Our Bronco Life coaches will be glad to take a look at what you have currently and get you set up for what works best for you!
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