HG's Adjustable Track Bar

[Classic Heartbeat]

All of the trucks that I worked on were a 6" drop in the rear. One may have been 5". They were 3" to 4" in the front. Generaly speaking 4" or less will be fine with an adjustible panhard in the stock location. By the time I see the trucks they have already changed all of the bushings, ball joints and etc. just because they are experiencing the problems that I spoke of. They come to me because they are at the end of their rope.. These trucks are definetly not precision, that's for sure, but they should be able to run 100 mph without scaring the you know what out of you. By the way, I like your panhard bar and think it's great. A lot of thought had to have gone into it and many will be the benifate from it. Great job!! WES

[hgs_notes]

Wes, I'm glad you chimed in. I can't begin to compare experience on these trucks to you, since I only deal with my own stuff and not paying customers. My bar works for me most likely because I have a mild drop by todays standards. This just gave me the ability to adjust it. I actually thought of just shortening it slightly first, but decided to go this way in case I was off a bit on my cut and reweld.

This board is a boon to us DIY'ers. Some ideas I really like, others I shake my head at. The good ideas stick, the bad ones fade away. I've tried a few things that didn't work. You won't find them posted anywhere.

[Classic Heartbeat]

I apriciate that. Your pan hard bar modification is a great one. It will save lots of people money that otherwise may not have lowered their trucks because of cost. You should come up with a kit with instructions. I bet you could sell a few offsetting your cost of working on your trucks. As you know people take a lot of pride in doing it themselves and if they save some money, that's even better. Keep up the good work! WES

[LilD]

Looking at this thread got me thinking. I went to our local roundy round supply shop and they have hex aluminum adjustment sleeves and nuts for under $20. Place is called Lefthander Chassis. If you have a local cicle track supplier you could save a few more bucks over Summits or Jegs stuff.

[crakarjax]

Originally Posted by Classic Heartbeat

I bet you could sell a few offsetting your cost of working on your trucks.

Yeah, but what will offset the cost of liability insurance for the product?

[vasquezmrysvll]

Originally Posted by crakarjax

Yeah, but what will offset the cost of liability insurance for the product?

[profe56]

Great job!!!!!

[Jeffs70]

oh great idea. I sure am going to have to do this very soon on my truck. thanks for the info and idea.

[lakeroadster]

This might help everyone to understand rear axle movement in regards to stock length track bar.

I modeled the rear suspension on Autodesk Inventor to see the articulation of the rear axle as constrained by the track bar and trailing arms. Truck is a '65 C10 with 5" drop springs.

Image below is an aerial view with frame at ride height:


I turned off the visibility of the gas tank so the rear axle / track bar could be seen more clearly.



Image below is the frame is at ride height (rear cross members removed to allow viewing of track bar)
Note angle of track bar in the following photos



Image below is the rear axle is hanging, being suspended by the coil springs. (Note: This moves the axle to the right a negligible amount < 1/8")





Image below is fully bottomed out; frame is on the top of the rear axle tubes. (NOTE: This moves the axle to the left approx. 11/16" from the std. ride height position)



Image below is fully articulated, hanging on left side, bottomed out on right side. (Note: This moves the axle to the right a negligible amount < 1/16")



Image below is fully articulated, hanging on right side, bottomed out on left side. (Note: This moves the axle to the left approx. 1/2" from the std. ride height position)

[hgs_notes]

Originally Posted by lakeroadster

This might help everyone to understand rear axle movement in regards to stock length track bar.

I modeled the rear suspension on Autodesk Inventor to see the articulation of the rear axle as constrained by the track bar and trailing arms.

Thanks for posting that. Do you have a similar model using the typical aftermarket longer track bar for comparison? I've also been wondering how much difference the shock relocators make and if there is a more optimum position for the shocks based on my 3.5" static drop.

[lakeroadster]

Originally Posted by hgs_notes

Thanks for posting that. Do you have a similar model using the typical aftermarket longer track bar for comparison? I've also been wondering how much difference the shock relocators make and if there is a more optimum position for the shocks based on my 3.5" static drop.

In regards to rear shock angles, check this link DIY Upper Rear Shock Relocation Brackets

Here is the data for the longer track arm that a just modeled this morning for ya'll. The longer bar helps, but not significantly. I am betting thats why GM never used them on these trucks.

I haven't been a big fan of these long bars simply because they aren't really needed on a street driven truck. Think about it. A stock 3/4 ton truck with stink-bug high rear end height, now fully load it down. Your street driven truck will never see more suspension travel than that, right?

Now if your running a rock crawling 4x4 with a lot of suspension travel like my buddy Tony's Bronco in the last photo below, the long track arm will make a whole lot of sense.

Image below is the frame is at ride height. Again, note angle of track bar in the following photos


Image below is fully bottomed out; frame is on the top of the rear axle tubes. (NOTE: This moves the axle to the right approx. 1/2" from the std. ride height position)


Image below is fully articulated, hanging left side, bottomed out on right side. (Note: This moves the axle to the right a negligible amount about 1/8")


Image below is fully articulated, hanging on right side, bottomed out on left side. (Note: This moves the axle to the right approx. 1/4" from the std. ride height position)


Here is a photo of an application of where a really long track bar yields the most benefit.... lots of articulation here:

[stich626]

I like it..
wonder if I can thread them with my tap and die set..
cheap is good

[crakarjax]

Originally Posted by stich626

I like it..
wonder if I can thread them with my tap and die set..
cheap is good

That would be a pretty large die, like the kind that plumbers use for iron pipe. Good idea! What is the OD on the stock panhard bar?

[stich626]

Originally Posted by crakarjax

That would be a pretty large die, like the kind that plumbers use for iron pipe. Good idea! What is the OD on the stock panhard bar?

not only that but home depot has the machines to cut thread..
and the adjuster (can't remember the name) just remove the eye hooks that come with them..
strong enough to chain stuff down it'll be strong enough here..

[vasquezmrysvll]

i believe the name is "turn buckle"?

[mcbassin]

Originally Posted by lakeroadster

I'll do a model with the longer track arm and post up a comparison.

In regards to rear shock angles, check this link DIY Upper Rear Shock Relocation Brackets

Cool shock relocator brackets. I like those, not sure the lower ones on your truck are the same geometry as 67-72? anyway, I can send you some geometry of the parts I made for my longer "home made" track bar. I simply modified a stock bar and made a new mounting bracket HERE. I would sure like to see how far my rearend is going to shift from side to side when bottoming, tilting or raising out. thanks

[stich626]

Originally Posted by vasquezmrysvll

i believe the name is "turn buckle"?

tel him what he's won

[lakeroadster]

Originally Posted by mcbassin

Cool shock relocator brackets. I like those, not sure the lower ones on your truck are the same geometry as 67-72? anyway, I can send you some geometry of the parts I made for my longer "home made" track bar. I simply modified a stock bar and made a new mounting bracket HERE. I would sure like to see how far my rearend is going to shift from side to side when bottoming, tilting or raising out. thanks

The 60-66 lower brackets are superior in strength to the later design because it captures the shock on both sides.


In regards to axle movement I posted up a modified model using the longer track bar.

Originally Posted by stich626

not only that but home depot has the machines to cut thread..
and the adjuster (can't remember the name) just remove the eye hooks that come with them..
strong enough to chain stuff down it'll be strong enough here..

You're a braver man than I if you trust a Home Depot aluminum turnbuckle as a track arm adjuster. I have used the Home Depot Turnbuckles for around the house projects. The tapped turnbuckle threads are very loose thread form, not a good thing in this application.

If you stick with components made for automotive suspension components you will have higher quality standards, better fit and finish and a better grade of materials being used.

[vasquezmrysvll]

Originally Posted by lakeroadster

The 60-66 lower brackets are superior in strength to the later design because it captures the shock on both sides.


In regards to axle movement I posted up a modified model using the longer track bar.

are these a direct bolt in?

[lakeroadster]

Originally Posted by vasquezmrysvll

are these a direct bolt in?

LMC's P/N 34-1250 for the control arm is the same for P/n for 63-72, that means the u-bolt spacing is the same, which means that yes they should be a direct fit.

Might need longer u-bolts?

[stich626]

Originally Posted by lakeroadster

[INDENT][INDENT][INDENT]

You're a braver man than I if you trust a Home Depot aluminum turnbuckle as a track arm adjuster. I have used the Home Depot Turnbuckles for around the house projects. The tapped turnbuckle threads are very loose thread form, not a good thing in this application.

If you stick with components made for automotive suspension components you will have higher quality standards, better fit and finish and a better grade of materials being used.

wasn't talking alum turnbuckle, haven't seen alum turnbuckles for use with chains, ones I've seen where steel

[Dano69c10]

Originally Posted by Classic Heartbeat

Hey Wes,
Dont' take this wrong (I respect you as an expert), but is that a mock-up pic?
I was wondering because it looks like the shock relocaters, trailing-arms and u-bolt bolts are below the rim. Disaster if you have a rear blowout.
I wouldn't want someone with less experience to have their suspension below the scrub-line.
Dano

[lakeroadster]

Originally Posted by Dano69c10

Hey Wes,
Dont' take this wrong (I respect you as an expert), but is that a mock-up pic?
I was wondering because it looks like the shock relocaters, trailing-arms and u-bolt bolts are below the rim. Disaster if you have a rear blowout.
I wouldn't want someone with less experience to have their suspension below the scrub-line.
Dano

Good eye Dano! Lowering blocks are a no-no unless you are running big diameter wheels like 20's or 22's. Even then one needs to watch for scrub line requirements.

Originally Posted by stich626

wasn't talking alum turnbuckle, haven't seen alum turnbuckles for use with chains, ones I've seen where steel

Same story.... not near the quality as automotive. They use looser thread class fits. Assemble one at the store and see how much slop there is.

[hgs_notes]

I used the edelbrock adjusters mainly because I thought they looked cooler and had more thickness and strength. The stock replacement tie rod adjusters would also work the same and be much cheaper. I think about $6 each and would likely be strong enough, considering they are used on the front steering everyday on all of these and millions of other vehicles.

You will not likely be able to thread the bar using your home tap and die set. Mainly because one side needs to be reverse threads and the cost of the die is about the same as buying a new bar. Also, The diameter is just a smidge to big so it should be turned down a bit for a standard die to cut the regular right handed threads. Thats why it was easier for me to just drop off the pieces a block from my house to the machinist for a very reasonable cost.

As far as side shift during articulation goes, if you want to loose it completely, there are systems available to do that. I forget the name of it, one of you guys will remember, but it basically puts a pivot point at the differential then has bars mounted above and below that are then mounted to the frame. It keeps it centered regardless of vertical motion. Primarily a road track suspension system.

I think 4 link set ups with triangulation will also work well, but not sure how the sideways motion compares on those.

But if you just want to get your axle centered again after a few inches of static drop, this will work. I'm glad to see the input and attention this is getting and hope it helps someone else out. I get so much from this board that I hope to give a little back.

Thanks again to lakeroadster for the modeling and input. I've seen his work elsewhere on the board and it's great info.

[lakeroadster]

Originally Posted by hgs_notes

....As far as side shift during articulation goes, if you want to loose it completely, there are systems available to do that. I forget the name of it, one of you guys will remember, but it basically puts a pivot point at the differential then has bars mounted above and below that are then mounted to the frame. It keeps it centered regardless of vertical motion. Primarily a road track suspension system.

Thanks again to lakeroadster for the modeling and input. I've seen his work elsewhere on the board and it's great info.

You are refering to a "Watts Link". Way overly complicated IMHO for a street truck, but they are very cool. Here's some links to threads:

http://67-72chevytrucks.com/vboard/s...ght=watts+link
http://67-72chevytrucks.com/vboard/s...ght=watts+link
http://67-72chevytrucks.com/vboard/s...archid=2315147

And you are welcome. Glad to help when I can.

John