Apex a-arm bolts?

[LazyBastard]

The bolts are supposed to be the first to give way in an impact. Every little bit of flexibility and springiness that you add to the front end is a MUCH better chance for the bulkhead to survive an impact.

Think about it like this; the bulkhead is CAST ALUMINUM. Move that by 1/32 of an inch and its broken. With a weak bolt there, it can take at least 1/8 of an inch away from the bulkhead.

Another observation that I made about the front suspensions happened last year when I lost an A-arm on a buried rock. Pretzel'd the lower arm, but the bulkhead is fine. Got a used arm from an 04 and noticed that the arm to bulkhead bolts were different. The 04 had a solid steel BAR whereas on the 03, the bar was hollowed out and had a bolt running through it. As it happened, this tube was bent on my 03 as well as the arm. If I had had one of the much stronger 04 solid bars, it most likely would have broken the bulkhead.

Because of the way that the bolt is separate from the bar on the 03, there is a mechanism for preventing the bar from turning inside the bulkhead, thus preventing any wear on the thin bulkhead bushings and limiting it to the very THICK arm bushings.


So my advise is to replace those pivot pin "bars" on 04+ models with the weaker 03 versions -- might save you a bulkhead one day.

 

[kinger]

"The 04 had a solid steel BAR whereas on the 03, the bar was hollowed out and had a bolt running through it."


Trying to picture this here, my stock 03 arms looked the same as the 06 apex arms I converted on my RX1, and those all looked the same as the CBperformance alumn front end. I twas a long bushing then a long bolt through that. Is that what you mean? Trying to figure out where something could be SOLID and let a bolt pass through the bulkhead through the arm, and back through the other side of the bulkhead.

 

[niko]

Now what we really need here is hardened alloy bolts that will bend.

 

[LazyBastard]

"The 04 had a solid steel BAR whereas on the 03, the bar was hollowed out and had a bolt running through it."


Trying to picture this here, my stock 03 arms looked the same as the 06 apex arms I converted on my RX1, and those all looked the same as the CBperformance alumn front end. I twas a long bushing then a long bolt through that. Is that what you mean? Trying to figure out where something could be SOLID and let a bolt pass through the bulkhead through the arm, and back through the other side of the bulkhead.

Call it a pivot pin. In the parts catalog I believe that they are actually listed as "collar" (which is not accurate). The bushing is the plastic thing between the pin and the bulkhead or between the pin and the a-arm.

And yes, the arms themselves are the same, but the pin is different. You remember the long bolt on the 03 that runs through the pivot pin to keep it in position. 04+ have a solid pivot pin.

 

[kinger]

I see here is the difference comparing the two. So what your saying is that because the 'pivot pin' is toleranced so that it can slide in out of the arm the arm is more thin (weaker) vs the 04+ the arm itself is actually thicker replacing the need for the pivot pin?

Its weird though because when I bolted up the 06 apex a arms I used the 03 mounting with the pivot pins. Are the bulkheads machined different to accomodate the pivot pin because it went through each side of the bulkhead and a arm so its almost as long as the bolt.

 

[LazyBastard]

No, I said that the arm itself is identical. And this has nothing to do with tolerances. This has to do with ABSOLUTE MASS OF METAL: a solid steel bar 1/2 inch in diameter is stronger than the same bar with a 3/8" hole drilled lengthwise down the center. If the bar is stronger than the bulkhead (04+), then the bulkhead will break. If the bulkhead is stronger than the bar (03), then the bar will break.

The difference is in parts 43 (04) vs 45, 48 (03). Despite the pictures, part 43 (04) is as thick (diameter) as part 48 (03), BUT, 43 is a SOLID STEEL BAR about 1/2" thick whereas 48 is HOLLOW. These parts are FULLY INTERCHANGEABLE, so 04+ can be UPGRADED to 03 specs.

Another good part related to this is part 33 on the picture you cropped for the 03 picture (not shown due to cropping).. that part ties the upper and lower pivot pins together and prevents them from turning in the bulkhead, which means that the bulkhead bushings on an 03 will exhibit NO WEAR EVER, leaving all the wearing to the MUCH MUCH THICKER A-arm bushings. This part was no longer possible in 04+ due to this design regression.

 

[kinger]

I gotcha ya now, thanks LB