Help with twitchy/jerky feeling suspension

[Teal68]

A friend has installed this 2.5" lift (linked below) and is now having issues with it being very twitchy/jerky with respect to steering. Says it's uncomfortable to drive over 45 mph. Drove fine before the lift.

He took it for an alignment and even with adjustable camber/caster joints this is what they said is best they could. See image.

Thoughts???? Maybe the C bushings are backwards???


https://shop.broncograveyard.com/25-Superflex-Lift-Kit-System-1966-75/productinfo/13740/


Thanks,
Tyler

 

[1969miller]

C bushings are probably in backwards or the wrong degree. 4 degree comes with most 2.5in lifts but couldn't hurt going to 7 degree

 

[Brush Hog]

Does it have adjustable drag link? That will get toe issue fixed. That is part of the problem. Then the list of things to work on begins. I started with 2.5 lift and new track bar and drag link then new tires. and a professional alignment. Then to 7 degree bushings. Then to drop pitman arm and drop track bar bracket. Then just last weekend added helwig front anti sway bar. Each change/upgrade made incremental improvements to my steering. The anti sway bar finally made it drive like a dream.

 

[Teal68]

Thanks for y'alls thoughts. I'll pass the info along.

Hog,
I forgot to mention it's a 76 and he sapped over to a T style linkage at the same time. Not sure what drag link came with the conversion.

 

[DirtDonk]

The linkage swap could be a major part of the issue. Or not...
What parts did he use? Is the tie-rod adjusted correctly where the draglink mounts? This is often (more often than not actually) left incorrect by the alignment specialists. Owners too, but more often by the techs.
Also, did he install a dropped pitman arm? The '76 has a much larger upper trackbar bracket than the '75 and earlier, so to just install the earlier style linkage without some kind of modification to the draglink angle will sometimes put things out of whack.
But adjusting the tie-rod center link incorrectly will double this effect.

paul

 

[DirtDonk]

Presumably that's the "before" or at least "during" the adjustment at the alignment shop? Or is that the official "after" reading?
If after, why did the tech not adjust the right side toe more to get it within spec? Is the steering wheel still centered? And if so, please tell me that nobody took the steering wheel off and re-centered it!
That's primarily what the adjustable draglink is for.

Regarding the crappy caster, I don't think the bushings are both in backwards. Unless they were 2 degree bushings? Or if higher, maybe just one is off?
If both were in backwards, and you changed them to correct, his Bronco would end up with either 4, 8, or 14 degrees of positive caster! Not likely to happen even on a '76.

Can't wait to hear more details. And if you can, get some pics of the front end that you can post up showing the linkage.

Thanks

Paul

 

[DirtDonk]

What tire size is he running, and on what wheels?

paul

 

[76YETI]

The linkage swap could be a major part of the issue. Or not...
What parts did he use? Is the tie-rod adjusted correctly where the draglink mounts? This is often (more often than not actually) left incorrect by the alignment specialists. Owners too, but more often by the techs.
Also, did he install a dropped pitman arm? The '76 has a much larger upper trackbar bracket than the '75 and earlier, so to just install the earlier style linkage without some kind of modification to the draglink angle will sometimes put things out of whack.
But adjusting the tie-rod center link incorrectly will double this effect.

paul

So, I just purchased WH early style linkage Y to T Swap (Item 2399) and haven't installed yet. What other parts are you suggesting as "just in case" if its a problem. Drop pitman arm? I am debating going to the 1.5" SL by WH. Have 1" BL installed and newer TBP stock suspension. It's a 76.

 

[Teal68]

Paul,
Good questions and thoughts. I'll see if I can get the owner of the Bronco to join in and answer some questions.
Thanks,
Tyler

 

[DirtDonk]

So, I just purchased WH early style linkage Y to T Swap (Item 2399) and haven't installed yet. What other parts are you suggesting as "just in case" if its a problem. Drop pitman arm? I am debating going to the 1.5" SL by WH. Have 1" BL installed and newer TBP stock suspension. It's a 76.

Yes, but not necessarily just the standard dropped pitman arm.
Any chance you can mock it up before you do your permanent install? Maybe just lay things up against the existing stuff, just to verify that the draglink angle will match the trackbar angle?
While the need is not 100% universal, it's often enough (maybe 80% or better?) needed to correct things, that it's worth the work.

My standard solution is to swap to the full-size dropped arm (our number #791275) and that puts most right near the sweet spot. But it's not a perfect solution to an off-road going Bronco.
As James Roney pointed out again a few weeks ago, the angle for the full-size arm is reversed to what an Early Bronco needs. So his solution is to heat it up and twist it to the desired angle for the most travel out of the draglink's upper end.
It's not a horribly hard thing to do for some, but it's out of the comfort zone for many. It would be nice if we'd just come up with a new design for the correct angle, but it's certainly a lot of effort and expense for the first ones, for a part that will not be sold in the great quantities of the other versions. Would therefore have to be more expensive than the standard fare.

Paul

 

[lars]

What were the "after" caster measurements? The "before" numbers are negative. Negative caster pretty much guarantees twitching steering (at least) even if everything else is ok.

 

[Brush Hog]

The way I read it is those numbers were as far as alignment shop could get it adjusted. So with that toe it’s a surprise he can drive it at all.

 

[DirtDonk]

I wonder… Did you get the tie rod for the 76 and 77? Or could you have the shorter one for the 66 to 75?
If you try to fit a 75 or earlier tie rod, you will be at the unsafe end of the threads on the tie rod end.
If you can even get it to work at all.

 

[Yeller]

He needs to find an alignment shop that can actually do work…. No reason toe can’t be set correctly with or without an adjustable track bar. It needs caster, put in some 7* bushings and find an alignment shop worth giving money to and it will drive well again. I’ve found most alignment techs have no business putting a wrench on your vehicle.

 

[Teal68]

He did comment that he didn't have much confidence in the alignment shop. Steering wheel is upside down too! I'll keep y'all posted.