Snake
Mopar Nut
WELL I am thinking on replacing my oem bushing with Moog k7 103.Will it make a big difference going that way? teach me, allso I have read about witch way the arrows face.SO I need to gain as much info as I can get. thankssssssssssss.
offset bushing
- Thread starter Snake
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my68barracuda
Well-Known Member
the off set bushings allow the front end alignment to dial in additional caster,
for a visual, think of the front wheels on a shopping cart, notice how the wheels set behind the axel, that off set is caster.
caster helps with straight line stability, the down side is an increase in steering effort,
when I rebuilt the front end on the 68 Barracuda I installed the off set bushings as well as swapped from power to manual steering, you can't park the car with one finger on the steering wheel, but I don't find the steering effort excessive.
The alignment shop was able to get 3.5 degrees of caster where the with the factory set up the max obtainable is 1 degree,, when you get the front end aligned be sure to have the shop dial in additional caster and not just set the caster to the factory settings.
ir3333
Well-Known Member
Using the offset bushing is a common modification.
I think the problem is sometimes worn or sloppy parts or if you want the
front end raised you will lose caster too..I have done quite a few front ends
and just used stock replacement rubber parts with good results at stock ride height,
but my original components were in good repair and i always changed everything.
Maybe the offset bushings are a good idea just to be sure.
I think the problem is sometimes worn or sloppy parts or if you want the
front end raised you will lose caster too..I have done quite a few front ends
and just used stock replacement rubber parts with good results at stock ride height,
but my original components were in good repair and i always changed everything.
Maybe the offset bushings are a good idea just to be sure.
I'm a fan of more caster but the problem is the higher the caster the lower the steering arm goes (outer tie rod). This causes bump steer, toe out or toe in as the front of the car lifts so you have to limit the travel of the suspension. If you look in any alignment spec book it will say caster angle for a certain ride height. That's to limit bump steer.
This is very small effect, and not worth withholding caster angle. The benefits gained from adding a few degrees of positive caster will far outweigh the small amount of bumpsteer you might add.
And we're not talking about a ton of caster. The offset bushings will only get you to around +3.5*, as my68barracuda pointed out. Most tubular UCA's will allow for +5*. Remember, the reason the factory didn't add more had nothing to do with bump steer. It was because of the bias ply tires. If you run radials, you want offset bushings, because your radials want more positive caster. Running radials with the stock alignment specs results in a poor handling car and less than great tire wear.
gdizzle
Well-Known Member
Just my 2 cents. My 66 dart has had a complete front end rebuild. And still the alignment shops cant get me enough caster...if any. I am interested in these offset bushings but have heard mixed reviews. Right now I have exactly no return to middle when I steer. And I do have the power assisted steering, which is also new. Let us know how it works out if you install them.
As far as I'm concerned, the k7103 offset bushings are a mandatory upgrade if you run radial tires. The factory parts put your alignment into a range of adjustment that is suitable for bias ply tires, and ONLY bias ply tires. That range of adjustment barely overlaps anything that I would consider tolerable for a radial tire alignment.
Seriously, take a look at the factory specs
Positive camber. Positive. Negative caster. That is what the stock parts are designed to get you for an alignment. That's a disaster for radial tires. You literally need the opposite. And when you make the camber negative, you limit the amount of positive caster you can get.
By adding the offset bushings you can get into using the SKOSH chart I posted above for setting your alignment. It's an older chart and honestly it's a little conservative as far as I'm concerned, especially for caster. But if you're just trying to build a street car with decent handling it works well. And with the offset bushings you can usually dial in a little negative camber and still get a few degrees of positive caster. And for a cruiser that's fine, the car will track much better and you'll have some return to center. Obviously the alignment specs also depend on the ride height.
So, I look at the offset bushings as a stock rebuild part unless you're running bias ply's. They're the minimum. You're not going to get to corner carver status with them, but you can get to what the factory would have spec'd if they'd built these cars for radials.
With a power steering set up you should have some "return to middle" from the steering box itself. What kind of numbers are you getting for your alignment?
Seriously, take a look at the factory specs
Positive camber. Positive. Negative caster. That is what the stock parts are designed to get you for an alignment. That's a disaster for radial tires. You literally need the opposite. And when you make the camber negative, you limit the amount of positive caster you can get.
By adding the offset bushings you can get into using the SKOSH chart I posted above for setting your alignment. It's an older chart and honestly it's a little conservative as far as I'm concerned, especially for caster. But if you're just trying to build a street car with decent handling it works well. And with the offset bushings you can usually dial in a little negative camber and still get a few degrees of positive caster. And for a cruiser that's fine, the car will track much better and you'll have some return to center. Obviously the alignment specs also depend on the ride height.
So, I look at the offset bushings as a stock rebuild part unless you're running bias ply's. They're the minimum. You're not going to get to corner carver status with them, but you can get to what the factory would have spec'd if they'd built these cars for radials.
With a power steering set up you should have some "return to middle" from the steering box itself. What kind of numbers are you getting for your alignment?
I'm following this thread, as I'm about to rebuild my entire front end and I did get the offset bushings. To reveal my ignorance, the above chart posted by 72bluNblu shows under the "carline" info the following columns - V and L, B and J, R and W, P and D, C, Y. What do these mean? They don't match up to anything I can figure out.
Snake
Mopar Nut
Well with all the info here its a no brainer,ofset it will be 120 canadian money well spent.PS I HAVE POWER STEERING CAR witch is leaking btw.
Very helpful, thanks! There's nothing better than a Secret Decoder Ring!
Yeah you really can't go wrong using the offset bushings. Even with them maxed out under the best circumstances you don't get a ton of positive caster. And with a power steering car you don't have to worry about any additional steering effort, you'll just get the benefit of having a more stable car.
Whoops, sorry about that. A-bodies are the V and L lines. The factory manuals changed to those designations somewhere in the run.
Snake
Mopar Nut
SO it still a + for my 71 B car. I must say I got more help on this site.Not much help from the B body site.Thanks
The offset bushings are a plus for any of the torsion bar suspension, muscle car era Mopars. They all came with the suspension set up for bias ply's, and they can all benefit from a little more positive caster if you're running radials.
The offset bushings only add a couple of degrees of caster, they install just like the OE bushings with exception of being directional. And once they're installed they really don't look all the different from stock. Unless you're going to run bias ply's I don't see a downside. Honestly I think the biggest drawback to them is that they don't add enough caster. They're ok for a cruiser and they're a big improvement over what you can get out of the stock bushings, but if you really want to handle you'd want more than what you can get out of them.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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Well my experience was a little different; but first I agree with everyone that says these are now a mandatory upgrade to the factory UCAs.
In my case I was able to get 6 and near 6 degrees of caster with zero camber. But I had to give up about 1.5 degrees per side to get .8 degrees of negative camber. And then, at the ride height I had selected, the bump steer was wicked. So I mapped it out, ( I was a tech at the time, and had unlimited access to the machine, after hours and Saturdays),and found the sweetspot that the front end was designed for, and set the ride height there. Of course that stole some more caster. So then I had to lower the rear of the car to get some back. In the end,after equalizing the sides, I had less than 4 degrees left over. So then I had to check the bump-steer again. And then I spent the best part of the day fixing that.
Then another roadtest. The factory toe-in just would not work, and I traced it to the scrub-radius. So I threw those wheels into the corner, and ordered up a custom set of 15s and some sticky-ish tires. I rechecked the bump steer, and reset the toe. And another roadtest. Ok now I was getting close. But that .8* camber was not gonna work, it was eating rubber at an alarming rate. I reset the camber to-.6ish , and redid the bump steer. And the toe . And more roadtests.
Keep in mind that this was with new and/or almost new parts.
So the factory tow setting was just not gonna work.
So I took my IR gun, and my toe-setting tools, and over the next couple of weeks I played with toe adjustments and tire pressures, in the field.
Soon I had it working pretty good, but those dang tires liked to follow pavement ruts pretty bad. You know, the grooves that the big-rigs leave on the softer tarmacs.And at normal speeds they had a tendency to wander annoyingly.
So back onto the rack for a final look see, and to center the steering box . And print a copy of what finally did work.
Shortly afterwards those soft SP8000s (245/50-15s)wore out. Flat across the faces. Great! And that was a lotta money for the fun-factor given, and winter was returning. So I tossed those worn outSPs and shelved the 8inch Rallys they came on,and dug out a set of zero offset 14" ET-IIs I had,and mounted up a pair of 235/60-14s which were about the same tall as the earlier tires.
And that was when it hit me............ These tires did not hunt......... Nor wander.
Ok so I learned my lesson.
These tires do like .6 camber. And they corner fast enough for me,lol. It turns out, those SPs were letting me get away with a lotta lack of finesse. These so called crappy Cobras/BFGs, do just fine for this now-much-older and more laid-back, old man,lol. And they give me plenty of screaming advance notice of the pain I am causing them. But by that time the 1.03s are fully wound up, and the front end is on the stops, and the slide has officially begun.Steering is now by gas-pedal. Hang on boys!,this'll all be over in a sec.....
That's my story and I'm sticking to it. I call it the summer of a thousand alignments.
So yeah, you gotta get those problem-solvers, for sure.
And IMO;
you need to stick pretty close to a Zero-offset front wheel, at close to the factory tire height, to maintain the factory scrub radius, and keep the ride height as close to the factory setting as possible; 0.8* negative camber is on the heavy side for wide rubber on the street; Rake steels caster;you need a big front anti-swaybar; you need 400 hp to have some serious fun;and big tires in the back, so the back stays in the back when the tires are spinning; and you need a private playground, cuz the cops don't like to see you doing that chit on city streets.
In my case I was able to get 6 and near 6 degrees of caster with zero camber. But I had to give up about 1.5 degrees per side to get .8 degrees of negative camber. And then, at the ride height I had selected, the bump steer was wicked. So I mapped it out, ( I was a tech at the time, and had unlimited access to the machine, after hours and Saturdays),and found the sweetspot that the front end was designed for, and set the ride height there. Of course that stole some more caster. So then I had to lower the rear of the car to get some back. In the end,after equalizing the sides, I had less than 4 degrees left over. So then I had to check the bump-steer again. And then I spent the best part of the day fixing that.
Then another roadtest. The factory toe-in just would not work, and I traced it to the scrub-radius. So I threw those wheels into the corner, and ordered up a custom set of 15s and some sticky-ish tires. I rechecked the bump steer, and reset the toe. And another roadtest. Ok now I was getting close. But that .8* camber was not gonna work, it was eating rubber at an alarming rate. I reset the camber to-.6ish , and redid the bump steer. And the toe . And more roadtests.
Keep in mind that this was with new and/or almost new parts.
So the factory tow setting was just not gonna work.
So I took my IR gun, and my toe-setting tools, and over the next couple of weeks I played with toe adjustments and tire pressures, in the field.
Soon I had it working pretty good, but those dang tires liked to follow pavement ruts pretty bad. You know, the grooves that the big-rigs leave on the softer tarmacs.And at normal speeds they had a tendency to wander annoyingly.
So back onto the rack for a final look see, and to center the steering box . And print a copy of what finally did work.
Shortly afterwards those soft SP8000s (245/50-15s)wore out. Flat across the faces. Great! And that was a lotta money for the fun-factor given, and winter was returning. So I tossed those worn outSPs and shelved the 8inch Rallys they came on,and dug out a set of zero offset 14" ET-IIs I had,and mounted up a pair of 235/60-14s which were about the same tall as the earlier tires.
And that was when it hit me............ These tires did not hunt......... Nor wander.
Ok so I learned my lesson.
These tires do like .6 camber. And they corner fast enough for me,lol. It turns out, those SPs were letting me get away with a lotta lack of finesse. These so called crappy Cobras/BFGs, do just fine for this now-much-older and more laid-back, old man,lol. And they give me plenty of screaming advance notice of the pain I am causing them. But by that time the 1.03s are fully wound up, and the front end is on the stops, and the slide has officially begun.Steering is now by gas-pedal. Hang on boys!,this'll all be over in a sec.....
That's my story and I'm sticking to it. I call it the summer of a thousand alignments.
So yeah, you gotta get those problem-solvers, for sure.
And IMO;
you need to stick pretty close to a Zero-offset front wheel, at close to the factory tire height, to maintain the factory scrub radius, and keep the ride height as close to the factory setting as possible; 0.8* negative camber is on the heavy side for wide rubber on the street; Rake steels caster;you need a big front anti-swaybar; you need 400 hp to have some serious fun;and big tires in the back, so the back stays in the back when the tires are spinning; and you need a private playground, cuz the cops don't like to see you doing that chit on city streets.
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I put the offset UCA bushes in my E body, I’ve done my own wheel alignment which basically I wind the rear adjuster so the bolt center is fully in toward the centre of the car, then I adjust the front cam adjuster to give me the camber angle I like which is about .75 in at the top, then do factory toe in, tires don’t scrub, at 100mph the car just sits on the road, so yep, love them
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