UCA Offset Bushings - Use them or not?

70 B-body.
Started researching suspension rebuild in 2013 and then got sidetracked. Looking to do it now. Some advice I had gotten on the board was to use Moog problem solver offset UCA bushings to get more caster needed with radial tires.


Any thoughts on the necessity of using the offset bushings versus standard? Looking at preloaded UCA's from Dr. Diff and would prefer not to have them swap out the already loaded standard bushings. Thanks

I have them in my 70 Charger. I was able to get 4.5 degrees of caster by using them. The car steers great!

Okay, excellent. Thanks!

The offset UCA bushings are helpful to get more caster/negative camber with stock UCA's. That is if they are installed right.

If you start with aftermarket UCA's which already have the extra caster/negative camber built in they should not be needed. Run the bushings supplied with the UCA which are probably poly.

I'm not sure if they made a noticeable difference when I used them...also not sure about the reverence paid to Doctor Diff but he is well respected so you think he would offer them if it was a viable option as implied; me thinks he does not as he buys them already assembled. Usually depending on the condition, one of the first things I do when buying an old Mopar is put on front disc brakes and rebuild the front end using reasonably price kits found on Ebay...with free shipping. I thought about getting new uppers with the ball joints and bushings installed but it is pretty easy to change them out...especially if you have the right socket for the ball joints. For the upper and lower bushings I usually use a combination of pipe nipples,nuts, bolts and washers to remove and install them. By the time you buy all the parts and pieces to do the job yourself your probably saving about $30/40 bucks sourcing Moog parts from Rock Auto over buying the the control arms already done....and still having the offset bushings.

Buy them and install them you will like it

Actual results can vary from car to car. Assembly tolerances when new were lousy and you put 50 years of neglect or abuse, and the results will vary even more. Some cars can get 6* with these, some will struggle to get up to 2*. In either case, it can give a 2-3* of additional adjustment over the standard bushing. For a few bucks more than a standard bushing, why not try them.

Thanks all for the feedback. I bought the Moog offsets.

Can confirm TCs statement. Range of adjustment can vary widely. After aligning a half dozen b bodies mine with offset bushings was the only one that could get over 2* caster without positive camber. The others were all standard bushings. Worst one couldn't get positive caster without positive camber but the owner had the rear end jacked up for tire clearance.

Extra camber is easy to gain by shimming the ball joint, if you cant get enough Caster.

Shimming which ball joint...upper...lower? How?

I should clarify my statement by saying that there may have been more adjustment offered by the offset bushings but I didn't notice much difference in the handling of the car. I also did not have the car long enough to weigh in on tire wear either. What are the optimal caster and camber settings for a 69 b body with a stock suspension, rubber bushings with a 15x7 wheel and a 235/70 tire?

~3 deg positive caster
~.25 deg negative camber

What where your measured alignment numbers before and after?

Putting hardened washers between the lower ball joint and spindle on the mounting bolts increases negative camber.

$18 from Andy
http://arengineering.com/products/tie-down-set-0-188-thick-3-inch-length/

andy makes very nice, and excellent quality items, but hardened washers at the local ACE hardware are only $1.60ea or so.

I installed the Moog Offset UCA bushing in my 68 Charger using the method below, but when I had it aligned the shop was only able to get about + 1.5 degs caster.

That is odd. I was able to get 4.5 degrees on both sides. It is strange how much these cars varied in the build tolerances.