Panhard/Trac bar placement advice.

[darwink1]

Ok, Ive looked around and might have some sort of idea of how to set up my trac bar but want to get some advice from the experts before I dive in any further...

Heres the set up just for reference. 69 fj40 frame, 86 bj60 axles f/r, 60 leafs outboarded in the rear, 4' long dom radius arms w johnny joints at the frame end and ford style mounts at the axle, coils. I have a bj60 steering box mounted to the outside of the frame rail and have shortened the 60 drag link to fit (cut 3/4" off on each side).

I have a couple johnny jointed trac bars that a buddy donated to the cause and am figuring out how to go about setting one up on the front of the fourty

So, form what I gather, the prefect trac bar would be the same length as the drag link, sit at the same angle as the drag link, and move through the same arc as the drag link as they both cycle up and down. Another site I came across seemed to insinuate that the trac bar can be shorter than the drag link as long its at the same angle, resulting in the same arc through their range of motion.

Ideally Im hoping that my trac bar can be shorter than my drag link due to space restrictions at the axle mount.

We made a bracket for the frame end of the trac bar and have it tacked in behind the steering box in what seemed like a decent location...

So, looking at the second picture, would it be best to try and bastardize some sort of bracket that straddles the radius arm mount or could I shorten the trac bar by roughly 4" and make a less complex bracket on the inside of the radius arm mount. I put a yellow mark on the trac bar where the proposed mount point would be after shortening the bar.

I hope this made some kind of sense, any advice/critique is appreciated.

Thanks in advance

D

 

[The Dude]

You have the basics figured out but in the end you have to go with what fits. remember you can bend the track bar as long as the line between the attachment points is what you want. Are you going to be running any type of hydro assist? That will help with bump steer.

Here is a picture of the drag link and trac bar on the front of my 61

and of just the trac bar with the bump to go over the dif.

 

[darwink1]

Nice! I do have a bender at my disposal...

D

 

[Gumby]

I had a bend in mine to clear the diff and that's where it bent. When it bent it went through the oil pan and into the number on connecting rod.

If you put a bend in it, make it extra strong.

 

[darwink1]

Dont think I will need to bend it to clear the diff, my main concern is lenght right now.

D

 

[yOHda]

you should try to make it as long as possible. but that is going to be one funky bracket to clear/allow access to your radius arm mount.

i think the shorter the panhard, the worse the bumpsteer(among other handling characteristics) is going to be.

another potential problem may be the angle of the drag link in relationship to the panhard. ive always read parallel to each other, parallel to the ground, and equal length if possible. the panhard can be shorter, but them being parallel is pretty important.

 

[darwink1]

Yeah, the way I have it mocked up now they're both sitting at 8* and are parallel. The trac bar is a couple inches higher than the drag. I think I'm gonna take four inches off of the trac bar and make a bracket on the axle beside the radius arm mount. I've looked at a couple buddies heaps and they all have track bars that are shorter than their drag links...

D

 

[40Habits]

my main concern is lenght right now.

D

The angle is more important than the differences in length. Try to keep it as long as possible.

Just an observation, but you have your panhard higher than your drag link. If the panhard is higher on the axle and frame it increases your roll center. If you bring the two closer to the same level it will decrease your roll steer. just my .02

 

[darwink1]

Gotcha.

D

 

[darwink1]

Figured Id finish off this thread instead of leaving it hanging.

Ok, first off thanks for the advice guys. After cutting 4" off of the trac bar and welding the bung back on we got the axle end bracket made up and it turned out great. We also moved the frame end bracket inboard a tad since it would have touched the coil when flexing and the trac bar bolt was next to impossible to put in/take out. The angles of the trac bar and drag link ended up exactly the same (7*). After everything was bolted together we bounced the hell out of the front end (easy to do with coils and no shocks) and could not feel any movement at the steering box output?. Im hoping that translates into no bumpsteer but Im no expert.

Flexed it out and nothing binds, bonus.

Still needs some finish welding and clean up but you get the idea. Bracket is bent 1/4" plate bent in a vice using a bfh.

D

 

[The Dude]

looks pretty good.