pinion angle

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greenracing
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pinion angle

Postby greenracing » Thu Mar 02, 2006 1:17 pm

This may stir up some debate because I know there's a lot of opinions out there....

How do you guys set your pinion angles? (OK all you fast guys with no suspension can ignore this one ;) )

I've seen people swear that it needs to be set at some particular angle, usually pointed down slightly. Then there's the camp that lines it up with the tranny angle - which could mean pointing it up.

Here's how I see it:

If you're running ladders or a 4 link, the rear end assembly can be seen as a solid peice with very little rotation. Hence, the pinion angle is not going to change dramatically like it would with leaf springs due to spring wrap-up. Plus, looking at it as a block box, the rotational torque load on the ladder bars and the car is the same regardless of where the pinion comes into the box.

U-joints are designed to be run in parallel. Hence, the u-joints are going to be happiest, and have the least amount of binding, if the pinion is parallel to the transmission. This means that if your engine is pointed down, the pinion should be pointed down at the same angle. Likewise, if the engine is pointing up, the pinion will be pointed up at the same angle.

I put the rear end at ride height and set the point angle to match the tranny angle.

I figure that this is the easiest on my u-joints, which is easiest on me...


Perry

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jim sanders
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Postby jim sanders » Thu Mar 02, 2006 1:37 pm

:?: my guess Perry would be any car with rear suspension allowing the rear housing to rotate at all requires a u-joint so i would think i would want the angles correct under acceleration considering the engine/trans is fixed on solid mounts/plate ?? which would call for a couple degrees or so down on the pinion flange at rest even with a snubber ?????

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pro70z28
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Postby pro70z28 » Thu Mar 02, 2006 1:49 pm

I'm setting mine up like this. The engine/trans. are level, actually up in back by maybe 1 degree .... almost. (Engine sets low). So to be parallel the pinion needs to be down in front the same amount. I plan to put the 4 link @ 2 degrees down maybe 3 ...almost, so under power the front and rear yokes will be parallel. Even a four link will have some wrap up because of slight play in the rod ends, a little flex in the chassis, etc. That's my theory anyway, and I'm stickin' with it. ....... :roll: .... unless of course somebudie' points out the error of my ways. :roll: :roll:

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pro70z28
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Postby pro70z28 » Thu Mar 02, 2006 1:53 pm

Doc., ya' beat me to it. :P :P :P I spend toooo much time on this detailed blueprint. :lol: :lol: :lol:
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jim sanders
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Postby jim sanders » Thu Mar 02, 2006 2:17 pm

:o pay no attention to me 70.... i deal with overloaded cargo vans all day riding on rubber rear housing bumpers.... trying to make em stop with impala B-R-A-K-E-S....... THE GATOR GUMBO car can coast to a stop with no brakes before the 1st turnoff....... just yakin' :oops:

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Gator
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Postby Gator » Thu Mar 02, 2006 5:28 pm

angle it down too much and you'll put in"bite" like you've never seen.
www.wallybell.com

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pro70z28
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Postby pro70z28 » Thu Mar 02, 2006 6:15 pm

angle it down too much and you'll put in"bite" like you've never seen.
This is my first go around with a 4 link. I'll be ajusting it a few times B4 I figure out what I'm doin' I'm sure. When I get it to the track, I'll hafta' rely on trial & error & you guys to get it dialed in.
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Gator
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Postby Gator » Thu Mar 02, 2006 8:10 pm

I agree with Green Racing & your illustration
either O or 1degree down.
You'll love the 4 link.
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pro70z28
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Postby pro70z28 » Thu Mar 02, 2006 8:45 pm

You'll love the 4 link.
That's what everybody says. I've got the books, I've got the tapes, just don't have the experience. Lookin' forward to givin' it a go.
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greenracing
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Postby greenracing » Fri Mar 03, 2006 7:20 am

I'd love to have a 4 link - but i've got to run with what i've been given until I can build a whole new chassis...

My engine is actually pointed up slightly (front is higher than the back). Is everyone in agreement that I should put the pinion at level to a little bit up?


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