prodigy

What is the correct way of adjusting upper and lower contol arms. Both the upper and lowers are adjustable, uppers are double adj. I adjusting lca to the stock length and then put uca on. Every time I got the pinion angle right the rearend was sticking out to one side about an inch or so. I just need a starting point and go from there. Could anyone help me with this question or give me a good place to go look at instructions so to speak. It is something that I think that should be easy but for somereason I can not find that easy button from staples.

randy78045

I'm not sure what youre sayin here, but i use calipers to make sure the adjustments are equal on both sides...

PX429

wasn't the easy button best buy? and why do noobs post and immidiatly log off?

prodigy

I closed the page and came back a few minutes later and it loged me off, not that I wasn't looking around at the other forums

randy78045

NooB...

prodigy

Oldies, I see you guys are still logged on, you better get to bed so you can get your fiber in the morning.

PRO50SC

Not a good way to get responses to your problems!!


Maybe tyhis will help.



SETTING PINION ANGLE



Need more traction out of your Steed? Try adjusting your pinion angle. As suspension gurus tell us, pinion angle is critical under hard launching conditions. The action/reaction tendencies of the Mustang's pseudo four-link suspension creates a pretty significant amount of axle rotation under hard launches. As the tires bite, the pinion's reaction is to rotate upwards towards the pinion snubber. This tends to unload the tires and create wheel hop. The optimum power transfer would be if you could get your transmission, driveshaft and pinion to form a perfectly straight line as shown in the top figure. Unfortunately, with articulating suspension, varying ride heights and other geometric considerations its highly unlikely that you'll ever wind up with that perfect alignment. When I'd measure my geometry with Megabite Jrs. lower control arms and stock upper control arms, my car had the pinion pointing upwards 2.5 degrees and the driveshaft pointing upwards 1.5 degrees (both running uphill when looking from the back of the car forward). I've tried to show this in the middle drawing. Under hard launches, the pinion will have a tendency to rotate 3 to 4 degrees upwards which was leaving my pinion pointing to the sky (well almost). I tried to limit this somewhat with a Competition Engineering adjustable pinion snubber (see photo here) but the initial upward orientation still wasn't what I needed. So then I installed a set of Unlimited Performance's double-adjustable uppers (see photo here). The adjustable uppers allow you to shorten (or lengthen) the upper control arm, which changes the initial pinion angle. By shortening the UCA length, I was able to get the pinion pointing about 2.0 degrees downward with the driveshaft following it to about 2.0 upward. This provides a total difference between the two of about 4.0 degrees downward (negative) pinion angle. Under hard launches, if the pinion rotates 3 to 4 degrees upward, it should just about straighten the driveline for maximum bite and power transfer.





So how do you measure the angles? I built four wood blocks of 2-by-12 lumber, two pieces thick by about 15 inches long. This way I can get the car far enough up in the air to crawl under and make the measurements and adjustments while still maintaining the normal ride height, weight distribution and driveline geometry. I bought a simple angle finder at Sears for about $10 that gives angles to the nearest 1/2 degree. To measure the driveshaft angle, simply place the angle finder on a straight and smooth portion of the driveshaft. To measure the pinion angle, I measure off the side of the pinion companion flange. There's enough flatness to the edge that if you're careful you can get a good read off the angle finder. Click here for an exploded view of the pinion and driveshaft measurement.



If you have converted your rear suspension to all spherical bearings instead of rubber or poly bushings, the deflection under load is going to be much, much less. In this situation, you want to set your pinion angle as neutral as possible with the car at its normal ride height.