JB151

iTrader: (3)

I've seen many threads on how to check your pinion angle but how do you actually adjust it. I have a UMI adjustable torque arm...is it the side bolts that I adjust? I don't need adjustable LCAs do I?

ninobrn99

iTrader: (8)

no, back by the pumpkin (the rearend) on the bottom, there is one big long double threaded screw with a jam nut on each end. loosen the jam nuts and adjust the big one accordingly.

JB151

iTrader: (3)

Even on the Moser rearend?

ninobrn99

iTrader: (8)

yeah, your not adjusting the rearend, your adjusting the torque arm. you know how you have the bracket that attaches to the rearend right? on the moser your using 4 bolts if its a 12 bolt or 2 long ones if its a 9". the triangular part that goes from the tranny to the bracket. on the botton of it close to the rearend bracket on the torque arm itself. If I had photoshop here at work, id circle it for ya.

JB151

iTrader: (3)

So I don't have to pull the driveshaft off??

ninobrn99

iTrader: (8)

personally, i would. put the protractor on the tail of the tranny and on the pinion nut on the rearend. that will give you a more accurate angle.

JB151

iTrader: (3)

So loosen the yellow arrow bolt then I can adjust it by changing the blue arrow bolt?

ninobrn99

iTrader: (8)

dont touch the yellow arrow. loosen the two blue ones. basically loosen them to where they're spinning towards the yellow arrow, but on free thread. the big one in the center is the one your gonna adjust. if the rearend is facing down, then its - if up, then its +....understand? Id be able to explain it better in person or over the phone, but that should clarify..i hope

jimmyblue

iTrader: (11)

I did mine with four Rhino ramps. Have to get under
it, with suspension loaded. Big fun when lowered.

I found it easiest (if you can call trying 5-6 different
nights easy) to go for dead level first. That means
the trans pan and the torque arm bottom plate are
indicating the same angle (with the angle finder in
the same orientation). The driveshaft should just be
ignored. Some instructions go on about it but it only
messes you up, trying to work two angles. Just cut
to the chase.

Anyway, get it to identical indicated angles, and then
crank it so the pinion snout points front-down by a
couple of degrees more. Easy way to keep it straight,
if you have to move the -rear- of the angle finder down
to get back to the original indicated value, you're
heading in the right direction (front down).

I've come to the conclusion that pinion angle is only
about minimizing driveline vibration / wear, and has
nothing directly to do with suspension reactions.
You can't change instant center much by twisting the
rear axle. You can change it by raising or lowering
the front of the TA (non-stock mounting scheme)
which of course would need you to adjust the pinion
angle again. But don't expect anything special from
cranking the angle, bite-wise. Just look to not feel
it buzz under coast, cruise or acceleration; if you
can get all three to quiet, you're done.

Usually the torque arm is discussed more in the
Handling & Braking section. Everything I know
(including a lot of stuff that just made it more
difficult to understand than necessary) I picked
up there, or from following down the links.