64 C10 Pinion Angle

[Leverhead]

Setting up a C10 with a 12 bolt...stock trailing arm suspension. How is the pinion angle adjusted on these trucks? Are there shims available? Seems like I need to get the pinion down a bit. Thanks.

[Leverhead]

Com'on guys...nobody here has ever adjusted their pinion angle? No info anywhere? Anyone?

[1963c-10]

I don't know personally, but does this help any? There was a good thread on the 67-72 side about pinions awhile back...might be worth a shot.
http://67-72chevytrucks.com/vboard/s...d.php?t=543726

Are you lowering the truck? I believe they are supposed to be 2-3*

[1963c-10]

Pinion angle shims
http://www.classicperform.com/Store/...k/6072RPS1.htm

[Leverhead]

Thanks for the replies. Looking at the pic above, I'm trying to get to the 2nd illustration ... seems i'm at the 3rd right now. Looking for shims specific to these trucks and their trailing arms...I'll check with CPP and see if those will work....otherwise.....????

[Captainfab]

A vendor that sells circle track parts should have the shims for the trailing arms. Try Speedway Motors.

[Leverhead]

Thanks...will do. I'll post my findings.

[Leverhead]

Seems like the ones from CPP are the way to go..ordered a pair of 3 deg shims..I'll post the results when I get them in. Thanks all.

[tincan1966]

What is your transmission angle? How much difference is there?
From personal experience, I will highly recommend not guessing at what it needs.

[Leverhead]

No guessing here....trans output shaft is 3 down and diff pinion is 6 up. My concern was finding the correct shims...3 should get me where i need to be at the current ride height.

[Leverhead]

Update: Got the shims and they are in (CPP part# 6072RPS-3 - pics attached).....looking much better now. Thanks for the replies...much appreciated.

[Rich 5150 69]

Note; you actually want a three degee downward tilt at the nose of the third member, during cruise situation and acceleration the third member will want to rise up at the nose.

[tincan1966]

Originally Posted by Rich 5150 69

Note; you actually want a three degee downward tilt at the nose of the third member, during cruise situation and acceleration the third member will want to rise up at the nose.

I would agree with this for a leaf spring truck, where you get a slight amount of spring wrap on accell, but with a trailing arm suspension, the angle of the differential varies very little thru the suspension travel and if you angle the pinion downward more than the parallel line of the transmission, you will experience driveshaft vibration and reduced u-joint life.

[Captainfab]

I agree

Originally Posted by tincan1966

I would agree with this for a leaf spring truck, where you get a slight amount of spring wrap on accell, but with a trailing arm suspension, the angle of the differential varies very little thru the suspension travel and if you angle the pinion downward more than the parallel line of the transmission, you will experience driveshaft vibration and reduced u-joint life.

[Rich 5150 69]

Has anybody checked the stock pinion angle on their truck...?

[tincan1966]

Yes mine was 3 1/2 degrees UP with stock suspension and only reduced to 3 degrees with the axle against bumpstops on frame. I am currently running at about a 4" drop in the rear and my pinion angle is at 3 1/2.

I had to shim my transmount 1/4" to get them parallel ( most likely could avoid this by researching a thicker transmount) I have the Urethane HD engine mounts which are obviously thicker and raised the engine slightly.

[Leverhead]

I'm at 3 degree up on the pinion and 3 degree down on the tailshaft and harmonic balancer. The carb flange is @ 0 and my pinion to driveshaft angle is approx -2 to -3....I'll start there. If necessary fine tuning can be had later after some test driving....especially after I get the front disk brake/lowering kit from CPP. They have shims from 1 to 4 deg....they are a little pricey though.