Anyone using offset upper control bushings ?

[bill440rt]

OK guys, just wanted to give an update on this thread after having my '68 back from the alignment shop after installing these offset upper control arm bushings from Moog.

Let me start by saying the overall feel of the car has definitely improved now. It used to feel somewhat "floaty", and had quite a bit of bump steer, which is pretty common for these cars anyway. Now, road feel is very much improved and bump steer is gone. That is good.

Any bad? Well, if you think you're going to get 5-6* of positive caster, you're not. However the alignment tech was able to get almost 2* of positive caster, which is still a great improvement over stock.
The rest of the suspension is stock design, and I'm running 15" wheels with 255/60 series radials. The car has manual discs from MP Brakes. The offset bushings were the ticket I think for this setup. Combined with the Stage 2 steering box it really has a nice feel to it now, much more stable. No, it's not a road course car but it's street manners greatly improved.

[myk]

Eh, the road course setup isn't all it's cracked up to be, especially when you spend it driving on mostly damaged infrastructure.  As long as you're satisfied then it's mission accomplished...

[HeavyFuel]

My car had an alignment performed yesterday because I also installed the Moog offset bushings sometime ago, but it took me a while to give up on trying to get the settings right on my own.  The car has a slightly lower than spec front ride height as well......not by much, maybe 1 inch. (Edit...just measured...1 5/8" was the measurement,  so about 1/2" lower than spec)

I've got stock upper and lower control arms (lowers are boxed).  I also have the FF stage II box.

The toe settings I did myself using string and a micrometer were surprisingly accurate.....+1/16" each side.  (of course those settings went out the window when they started resetting the camber and caster.)


Camber ended up +1/2* left and +3/8* right......no negative was achievable if any positive caster was to be had.

Caster is +7/8* left and 1 1/8* right.  Thats all they could get if the side to side difference was to be in spec.  One side they could have gotten more, but the other side had issues.


The handling is pretty decent considering I'm still running 14" Magnums and 70 series Coopers.

[Kern Dog]

I don't know how people are unable to get closer to 4 degrees. I have totally stock upper A arms and the offset bushings allowed me to get 4.7 on one side and 4.8 on the other. Before with the urethane upper bushings I was still able to get a smidge over 2.25 degrees on each side. Maybe you guys needed to have the bushings pressed in relative to the position the UCA sits at ride height?
If the offsets are not oriented just right, you give up some of what you are trying to gain.
Caster does help stability a great amount. Another benefit is that it increases steering effort as well. You lose some of that "tires on ice" feeling the stock Mopar steering box often has.

[myk]

Can there be "too much" positive caster?

[HPP]

Yes and no. Modern cars run upwards of 8* positive caster, which may seems like a lot. With a manuals steering car, 2-3* positive can feel like too much. There is a point where geometry and tire size can introduce a wobble with excessive positive caster, but its unlikely any of us can reach that point unless you use a particularly small diameter tire.

I tend to agree with Kern dog that you have to be especially careful when installing the offset bushings to maximize their caster results. While every car and combo is slightly different, I would think you should be able to get at least 2* positive out of the stock set up and 4* with the offset set up. If not, then I'm not sure what to say. After all, that is why they created these "problem solver" parts in the first place...to give additional range, even if that range is not equal to other cars.

[Highbanked Hauler]

Caster is +7/8* left and 1 1/8* right.  Thats all they could get if the side to side difference was to be in spec.

     HA, thats almost what I got on mine initially .  It was +3/4 on the left and + 1 1/4 on the right. Camber was at 0 as I remember.  As soon as I get brake pressure I am going to get mine aligned.

[bill440rt]

After all, that is why they created these "problem solver" parts in the first place...to give additional range, even if that range is not equal to other cars.

Bingo.
I think the tolerances between cars has a lot to do with it. Compared to a new car, they are downright sloppy.
The upper bushings were installed correctly. Truth be told, the tech found they were initially installed incorrectly (not by me), so he was getting really bad NEGATIVE caster readings. So, ponied up for a second set which were then installed clocked the right way. About 2* positive caster was all he could get out of it while still getting a good camber reading.
Compared to what it was, it drives much better now & I'm happy with it.     

[Brass]

Weird. I ended up with +2.74 caster on the driver side and +2.64 on the passenger. Camber came out -0.45 on each. Stock control arms and bushings. 

[HeavyFuel]

I don't know how people are unable to get closer to 4 degrees. I have totally stock upper A arms and the offset bushings allowed me to get 4.7 on one side and 4.8 on the other. Before with the urethane upper bushings I was still able to get a smidge over 2.25 degrees on each side. Maybe you guys needed to have the bushings pressed in relative to the position the UCA sits at ride height?  If the offsets are not oriented just right, you give up some of what you are trying to gain.
Caster does help stability a great amount. Another benefit is that it increases steering effort as well. You lose some of that "tires on ice" feeling the stock Mopar steering box often has.

Are yours installed according to this diagram?   Mine are just like the picture shows.

The UCA is roughly horizontal through it's average range of motion, correct?   So by using the arm of the UCA as a guide, 'pointing' the bushing center towards or away from the far end of the arm should be right, do you agree?

[HeavyFuel]

After all, that is why they created these "problem solver" parts in the first place...to give additional range, even if that range is not equal to other cars.

Bingo.
I think the tolerances between cars has a lot to do with it. Compared to a new car, they are downright sloppy.
The upper bushings were installed correctly. Truth be told, the tech found they were initially installed incorrectly (not by me), so he was getting really bad NEGATIVE caster readings. So, ponied up for a second set which were then installed clocked the right way. About 2* positive caster was all he could get out of it while still getting a good camber reading.
Compared to what it was, it drives much better now & I'm happy with it.     

Bill, you've got one of each year......was there any difference in specs from year to year?   Did they change the mount points on the frame or UCA geometry between years....or are all 2nd gens in the same boat?

[Highbanked Hauler]

Heavy fuel that is how I put mine in just what your diagram shows and as soon as I get brake pressure I am getting it aligned.

[HPP]

After all, that is why they created these "problem solver" parts in the first place...to give additional range, even if that range is not equal to other cars.

Bingo.
I think the tolerances between cars has a lot to do with it. Compared to a new car, they are downright sloppy.
The upper bushings were installed correctly. Truth be told, the tech found they were initially installed incorrectly (not by me), so he was getting really bad NEGATIVE caster readings. So, ponied up for a second set which were then installed clocked the right way. About 2* positive caster was all he could get out of it while still getting a good camber reading.
Compared to what it was, it drives much better now & I'm happy with it.     

Bill, you've got one of each year......was there any difference in specs from year to year?   Did they change the mount points on the frame or UCA geometry between years....or are all 2nd gens in the same boat?

There were not any documented changes between the years  during the 2nd gen run. With that said however, factory tolerances were sloppy at best with a .25" variation not only possibly, but passable on the assembly line.

[HeavyFuel]

After all, that is why they created these "problem solver" parts in the first place...to give additional range, even if that range is not equal to other cars.

Bingo.
I think the tolerances between cars has a lot to do with it. Compared to a new car, they are downright sloppy.
The upper bushings were installed correctly. Truth be told, the tech found they were initially installed incorrectly (not by me), so he was getting really bad NEGATIVE caster readings. So, ponied up for a second set which were then installed clocked the right way. About 2* positive caster was all he could get out of it while still getting a good camber reading.
Compared to what it was, it drives much better now & I'm happy with it.     

Bill, you've got one of each year......was there any difference in specs from year to year?   Did they change the mount points on the frame or UCA geometry between years....or are all 2nd gens in the same boat?

There were not any documented changes between the years  during the 2nd gen run. With that said however, factory tolerances were sloppy at best with a .25" variation not only possibly, but passable on the assembly line.

1/4" up or down, back or forth could make a huge difference as far as caster potential.  The offset bushings only get you about that much.   No wonder some cars with stock suspension obtained decent settings, while others struggle.

[bill440rt]

After all, that is why they created these "problem solver" parts in the first place...to give additional range, even if that range is not equal to other cars.

Bingo.
I think the tolerances between cars has a lot to do with it. Compared to a new car, they are downright sloppy.
The upper bushings were installed correctly. Truth be told, the tech found they were initially installed incorrectly (not by me), so he was getting really bad NEGATIVE caster readings. So, ponied up for a second set which were then installed clocked the right way. About 2* positive caster was all he could get out of it while still getting a good camber reading.
Compared to what it was, it drives much better now & I'm happy with it.     

Bill, you've got one of each year......was there any difference in specs from year to year?   Did they change the mount points on the frame or UCA geometry between years....or are all 2nd gens in the same boat?

There were not any documented changes between the years  during the 2nd gen run. With that said however, factory tolerances were sloppy at best with a .25" variation not only possibly, but passable on the assembly line.

1/4" up or down, back or forth could make a huge difference as far as caster potential.  The offset bushings only get you about that much.   No wonder some cars with stock suspension obtained decent settings, while others struggle.

Yep.
Just an FYI I had my bushings installed according to that diagram and they were... wrong. 
Don't go by arrows, you have to watch which way they are clocked. Mine were initially clocked wrong, hence the negative readings. Only until they were reversed was the tech able to get the positive readings.
Just be careful when you install them.        

[HeavyFuel]

Bill, you lost me.

How can the bushings be off from what the 'moulded into the rubber' arrows indicate is the right direction?

[bill440rt]

Bill, you lost me.

How can the bushings be off from what the 'moulded into the rubber' arrows indicate is the right direction?

A mechanic that pressed them in for me pressed them in according to that diagram. I checked them also before installing them on the car to that diagram. He put them in with the arrows as facing in that diagram.
However, when the wheel alignment guy tried to get an alignment he was getting NEGATIVE caster readings, and showed me why. The direction of the bushings was wrong. 
The bushings had to be reversed.     
It just cost me more time. And money...   

[cdr]

when i put mine in the instructions were wrong. I put them in how they should be.

[HeavyFuel]

Bill, you lost me.

How can the bushings be off from what the 'moulded into the rubber' arrows indicate is the right direction?

A mechanic that pressed them in for me pressed them in according to that diagram. I checked them also before installing them on the car to that diagram. He put them in with the arrows as facing in that diagram.
However, when the wheel alignment guy tried to get an alignment he was getting NEGATIVE caster readings, and showed me why. The direction of the bushings was wrong. 
The bushings had to be reversed.     
It just cost me more time. And money...   

Hell, I must be dain bramaged.   The arrows are logical to me.

By installing the bushings as shown, the front arm of the UCA is essentially 'lengthened' by a smidgen, and the rear is shortened.  That will move the upper ball joint rearward, and increase caster.

Right?   

[bill440rt]

Yeah, it confused the crap outta me, too.      
My wheel alignment shop was getting negative readings, only until he reversed them he was getting positive readings.

[HPP]

The bushings were originally created to address camber problems. If you install them per Moog's instructions, you get additional positive camber. If you offset them as being discussed here, you can create additional positive caster.

[myk]

Why would someone want positive camber?

[HPP]

Rust, damage, structural compromise, I have no idea, but  71 SE3834V  might be able to answer that.

[71 SE3834V]

Rust, damage, structural compromise, I have no idea, but  71 SE3834V  might be able to answer that.

You rang?

[HPP]

You're looking for positive camber. Might have to try to problem solver upper arm bushings and leave  it at that.  This is what they were originally created.