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Moog "problem solver" offset upper control arm bushing orientation
https://slantsix.org/forum/viewtopic.php?t=68537		 Page 1 of 1
Author:  Reed [ Fri Feb 13, 2026 11:56 pm ]
Post subject:  Moog "problem solver" offset upper control arm bushing orientation
I have been digging into the pile of parts I have been collecting for my 1976 D100 for the last 11 years and I have discovered that I ordered a set of the Moog "problem solver" upper control arm bushings with the offset bushing. This places the sleeve for the UCA bolt almost touching the edge of the bushing shell.

Obviously the offset means that there is now an optimal orientation at which to install the bushing to obtain the greatest benefit from the offset bushings.

My admittedly tenuous grasp of caster, camber, and toe and how those adjustments affect handling leads me to the following conclusions:

(1) the best "handling" or steering stability (tendency of steering tires to self-return to center and for the vehicle to track in a straight line) is achieved with POSITIVE CASTER (the upper ball joint is farther to the rear of the vehicle than the lower ball joint)

(2) to achieve the maximum increase in POSITIVE CASTER, the forward offset bushing should be installed in the UCA with the sleeve for the retaining bolt as far OUTBOARD as possible and the rear bushing should be installed in the UCA with the offset sleeve as far INBOARD as possible.

Are my conclusions correct? Is there a better way to install these offset UCA bushings? Any insights are appreciated.
Author:  Dart270 [ Sat Feb 14, 2026 12:24 pm ]
Post subject:  Re: Moog "problem solver" offset upper control arm bushing orientation
Yes, more positive caster will be more stable and usually better with modern radial tires. However, do not go crazy. Maybe add 2-3 deg positive beyond the stock number.

You want the upper control arm to be pushed backward at the upper balljoint, so installing the bushings to bring the rear of the UCA inboard and front of the UCA outboard is right. The way you have written it is ambiguous or maybe looks backwards regarding where the bolt goes through the bushing and the UCA.

Lou
Author:  Reed [ Sat Feb 14, 2026 12:59 pm ]
Post subject:  Re: Moog "problem solver" offset upper control arm bushing orientation
Quote:
You want the upper control arm to be pushed backward at the upper balljoint, so installing the bushings to bring the rear of the UCA inboard and front of the UCA outboard is right. The way you have written it is ambiguous or maybe looks backwards regarding where the bolt goes through the bushing and the UCA.

Lou
Right, we're saying the same thing, I am just not saying it well. Putting the forward UCA attaching bolt outboard and the rearward UCA attating bolt inboard would have the effect of pushing the upper ball joint toward the rear of the truck. I will keep your 2-3 degree number in mind when I go in for the alignment. Thanks!
Author:  Greg Ondayko [ Sat Feb 14, 2026 5:26 pm ]
Post subject:  Re: Moog "problem solver" offset upper control arm bushing orientation
Yes. Lou's instructions are correct and may differ from what it says in the package instructions.
Author:  Reed [ Sat Feb 14, 2026 8:04 pm ]
Post subject:  Re: Moog "problem solver" offset upper control arm bushing orientation
Thanks! I didn't know they came with instructions. I will check the boxes again.
Author:  Dart270 [ Sun Feb 15, 2026 12:28 pm ]
Post subject:  Re: Moog "problem solver" offset upper control arm bushing orientation
As Greg said, the instructions are usually NOT what you want to do as they say to install it with both bushings in the same orientation.

Lou
Author:  Reed [ Sun Feb 15, 2026 12:37 pm ]
Post subject:  Re: Moog "problem solver" offset upper control arm bushing orientation
Right. I figured there wouldn't be instructions since if you know enough about suspensions to buy these bushings, you probably know how the installation orientation affects the suspension. So, fore OUT, aft IN.
Author:  mcnoople [ Wed Feb 18, 2026 7:37 am ]
Post subject:  Re: Moog "problem solver" offset upper control arm bushing orientation
If you have problems finding a shop that knows how to align your truck take it to a toyota dealer. As stupid as it sounds they will likely have a tech that is familiar with adjusting camber,caster,toe with eccentric bolts. Those adjustments have been standard on 4wd toyota trucks/full frame suvs for years. I was at a toyota dealer doing truck frame replacements about 15 years ago and had to do many alignments from a clean slate on fresh frames.

Tell the tech to ignore the printed specs for the vehicle in regards to camber and caster. The numbers they should shoot for is the maximum positive caster that can be achieved on both sides. So if they can get 2.1 max caster on the drivers side then 2.1 would be the target for the passenger side. If +2.1 can't be achieved on the passenger side they would have to go back and match the drivers to the new lower number from the passenger side. To throw a nice added curveball in the camber is adjusted while adjusting caster. A good target for camber would be -.5 degrees per front wheel.

So the TLDR version is to run as much caster as you can get with -.5 camber.

A good tech will know how to edit/adjust the specs on the alignment program to reach the desired goal. And make sure to get a printout of all 4 wheels. The rear end is not adjustable BUT if you have a wonky total toe number (bent housing) or a high steer ahead number (housing not straight in frame) the printout can tell you much.
Author:  Reed [ Wed Feb 18, 2026 3:55 pm ]
Post subject:  Re: Moog "problem solver" offset upper control arm bushing orientation
Thanks, McNoople! This is good info. I will try and find a shop that will align to MY specs and knows how to work on older technology.
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