7" Lower - Track Bar Relocation Needed?

[customfab4x4]

So I'm done with the notch and have done a 7" drop in the rear with a combo of 5" coils with 2" drop blocks.

I noticed some people relocate the track bar attachment at the crossmember. Some basically flip that existing OEM bracket to raise the attachment point (looks to be about 4" raise).

I also noticed some not changing anything.

I understand that lowering these trucks results in a small arc for the track bar. So theoritically the rear axle is pushed back just slightly.

However, I've checked it out at max articulation. Axle sits perfectly in the C-notch. I'm also getting a new driveshaft made as I upgraded to a 9.76" axle with discs.

Guess I'm wondering what, if any, advantages are for relocating the track bar to a higher location at the crossmember.

Thanks!

[HO455]

AI am confused as to what exactly your asking about. The Track Bar/Panhard Bar is the bar that goes from the frame on the drivers side to the axle on the passenger side of the pumpkin. ( Small bar in center of photo #1).

The track bar should be level at ride height or the axle end slightly lower. The further the track bar is from level the more the axle moves side to side as the axle moves up and down. This side to side movement means the axle is no longer 90 degrees to the centerline of the chassis. When that happens the rear axle is steering the rear of vehicle. Best to avoid if possible.

I believe that you are asking about moving the Trailing Arm/Truck Arm mounts up on the crossmember?

If so, when you lower the rear of a coil spring truck the pinion angle of the rear end drops downward due to the built in angle of the Trailing Arms. The farther you drop the suspension the worse the angle becomes.

There are several ways to correct this.

1. You can remove the mounts on the axle and reweld them back on with the pinion angle in the correct position. Not everyone's up to this task.

2. You can add wedge shims under axle mounts to move the pinion angle up to an appropriate angle. If the truck is extremely low you might have to stack shims or have custom shims made.

3. You can also raise the front Trailing Arm mounts to restore the factory geometry of the arms and the pinion angle. There is a limit to how high you can go without interference from the body or frame.

You may find you need to use a combination of #2 and #3.

You will need to determine what your pinion angle is to determine which method would be best for you. Not every truck sits the same with similar drops mostly due tolerance stacking during the manufacturing of the frame and sagging from work and abuse over the years.

And Welcome Aboard! We would love to see some pictures of your truck.

[CC69Rat]

Are you referring to the trailing arms, where they make the connection to the cross member behind the cab? (Where the drive shaft comes through)

Totally cool if you are.. just clarifying.

Yes, on trucks with big static drops it is possible to flip that bracket over and raise the mounting point of the FRONT of the trailing arm. Essentially what you're doing is just rolling the pinion back around very close to where it was from the factory. Is it required? Not at all. But if you're planning to AutoX or drive it like you stole it, you might look into it more

The truck will ride, drive, handle closer to where it was designed. It will 'think' it has only been lowered an inch or two, vs 5" (+ blocks)

BUT - it's a major pain to do it.

Do you have a nice air hammer? Do you plan to re-use the factory brackets or go with aftermarket? I have used the Hotchkis brackets and they were very nice. (Sold the truck)

It works though! But make no mistake. It's a pain. Especially if your cab is still on the frame. It would be easy to do with the cab off.

Just my .02

[Richard]

I think where the confusion is, people flip the front trailing arm mounts. Nothing to flip on the track bar as I understand. As stated keeping track bar level at ride height is best. It will minimize movement (side to side) on one side vs the other. Bar swings in an arc, nothing can change about that. Aftermarket bars that use brackets to level bar and make it longer can be usefull with bigger drops. A longer bar will have a larger arc and will minimize movement vs a level stock length bar.

[MikeB]

I think he's referring to the track bar (a.k.a. Panhard bar), not trailing arms. I don't have an answer to his question about relocating its frame mounting point, but I can say that 7" of lowering might have pushed the axle farther to one side of the truck. To re-center the axle, simply use an adjustable track bar. I've had one on my 69 for 20+ years.

And, yes, the drive line angles need to be checked and probably adjusted with 7" drop.