It amazes me what people can get used to driving. Everyday some bloke will bring his rig in to get that shiny new light bar or angry jeep grill etc. Proceeding to drive it even around the building gives me a symphony of pops and creeks and a steering wheel like a wild stallion refusing to be tamed that NO light bar will remedy. Ask the customer about it, he said it drives fine or puts it down to “it’s a jeep thing” hence, horse and buggy syndrome.
We know there’s drivability sacrificed when lifting and adding large tires to our rigs, they will never drive like a stock machine. Although most lift and tire combinations can be fine tuned to drive quite reasonably on-road and still embarrass any obstacle off the pavement. Let us start with some checks any reputable shop would do right away regardless of which brand light bar your buying.
The Dry Steer
A dry steer test is a simple yet very effective diagnostic test. Simply get another human (clever dog maybe) to hop in the driver seat with the vehicle running, get them to rock the steering wheel back and forth at a good pace. With a flashlight take a close look at the front steering and suspension components including;
- Tie rods
- Universal joints
- Track bar
- Control arms
- Steering gear input & output
- Unit bearings
If any of these components have suspicious play they should be at least investigated further or changed. If you are unsure of what “suspicious play” may be, observe the oposing side.
Example if the drivers side tie rod on the knuckle is popping up and down it’s unlikely for all the tie rod ends to be equally worn giving you a clear comparison. While under the front end, look for any grease nipples. These should be greased on occasion to prevent moisture and metal on metal wear. They are also a good indication that the component with said grease fitting has been changed at some point as most stock components are not serviceable, “only upper ball joints on wranglers are serviceable from the factory”. Torn grease boots should be replaced if the component hasn’t already failed.
Universal joints can be observed binding or popping on a dry steer. Putting a pry bar between the u joint cap and inner C on the axle can also check for play. Physically grabbing the inner axle shaft and rocking it around to check for movement is also recommended. Look carefully for cracks on the caps and rust around the base of the caps where they meet the joint body, this indicates they have dried up inside and need replaced.
A solid axle vehicle will almost always have a “track bar” that centers the axle. This may have rubber, poly or a tie rod style ends one attached to the frame or body, the other the the axle assembly. These ends should have very little to no movement. The Track bar also plays into steering geometry and should be as parallel to your upper most drag link as possible to avoid bump steer. This can be checked with a piece of string held up to the track bar and visually compared to the drag link. Overcoming the difference in angle can be achieved using certain aftermarket brackets to raise or lower one end of the track bar or aftermarket bars and steering components can be had. Another benefit to an aftermarket bar is the adjustable length, this can be used to centre the axle under the vehicle as it tends to be pushed to one side after suspension height changes.
Ball joints must be checked off the ground. On a solid axle truck the axle can be free hanging or under load (on jack stands). Grab a pry bar and place it in between the lower knuckle and lower C where the ball joint is housed and pry up and down, if any gap or lateral play shows it is worn. Repeat on the upper. IFS trucks need to be under load to do this test, not free hanging.
While in the air, grab each wheel and rock it side to side to double check for unit bearing play and up and down as a secondary ball joint check.
Keep in mind, most of the factory components are NOT designed to run huge tires. Some exceptions include the Dana Spicer end components ie. Universal joints and ball joints. That said if your stock components need replacing and you are running bigger than stock tires or plan to, consider an aftermarket upgrade component that is built for the task. It exists, trust me.
The factory control arms are known to actually have very durable rubber bushings. If they are starting to go downhill, you will see side to side movement on a dry steer. Look for cracks in the bushings and on the axle ends if the bolt holding them in place is no longer centre the inner sleeve is being pulled back in the bushing, which is no good.
I put “control arms” under alignment as adjustable control arms “available in many brands” will help dial in caster and pinion angle. Camber is usually unable to be altered on a solid axle vehicle. On IFS trucks upper or lower control arms will have cam centric bolts for camber and caster adjustment.
Now that your front end is tight, (head out of the gutter people) alignment is tremendously important to getting you’r custom built street legal flame spewing light bar rocking buggy crawler driving right and extending tire life. You can do a decent home check on alignment with some basic tools and perform some basic adjustments such as checking your toe setting and centering your steering wheel. After any front end work is done however, the vehicle should be taken to a shop for a proper alignment. Be prepared if running older steering equipment, the adjustment portion may not move because of rust. You could be looking at more parts or labour to free them up.