Pinion angle.

[97singlecab]

I finally have the front and rear ride height set on the prostreet truck im building. What im wondering is if any racers have some input on what kind of pinion angle I should set my truck to. As well as a good starting point for the 4 link bars. The rear setup is a chris alston chassis works back half with 4 link and anti roll bar. Running 34x17 slicks. Any info on a good starting point would be greatly appreciated. Here are some pics.

 

[rnemovr]

Your pinion should point directly to the out put of trans (transfer case if 4wd).

 

[1-5-3-6-2-4]

Ideally it should be a couple degrees under, so when it'd loaded up it points directly at the output shaft. And that's for a CV joint st the top of the driveshaft.

If you are planning to use single joints at each end. You want the pinion angle parallel to the output shaft under load.

Sent from my HTC Desire HD A9191 using Tapatalk 2

 

[97singlecab]

Thanks for the info. Pretty new to this level with 2wds.

 

[rockjeep73]

1* down on the pinion angle, that is measured in relation to the driveshaft.

As far as the fourlink, have the hole locations been plotted out so that you know all of the instant center options? If not take a measurement of the center to center distance of the top and bottom 4 link bars on the rearend housing with the bottom bar in the very bottom hole and the top bar in the very top hole. Also get a measurement of the bottom bar center to center length. Last measurement that would be helpful would be center of the very bottom hole on the chassis bracket to the ground, this would be taken with the truck sitting on the ground at ride height.

With those measurements I can help you out with where to start on the 4 link.

 

[97singlecab]

1* down on the pinion angle, that is measured in relation to the driveshaft.

As far as the fourlink, have the hole locations been plotted out so that you know all of the instant center options? If not take a measurement of the center to center distance of the top and bottom 4 link bars on the rearend housing with the bottom bar in the very bottom hole and the top bar in the very top hole. Also get a measurement of the bottom bar center to center length. Last measurement that would be helpful would be center of the very bottom hole on the chassis bracket to the ground, this would be taken with the truck sitting on the ground at ride height.

With those measurements I can help you out with where to start on the 4 link.

Nothing has been plotted for instant center but I will get those measurements tomorrow. Thanks for the help man.

 

[97singlecab]

1* down on the pinion angle, that is measured in relation to the driveshaft.

As far as the fourlink, have the hole locations been plotted out so that you know all of the instant center options? If not take a measurement of the center to center distance of the top and bottom 4 link bars on the rearend housing with the bottom bar in the very bottom hole and the top bar in the very top hole. Also get a measurement of the bottom bar center to center length. Last measurement that would be helpful would be center of the very bottom hole on the chassis bracket to the ground, this would be taken with the truck sitting on the ground at ride height.

With those measurements I can help you out with where to start on the 4 link.

center to center of the top and bottom bars at the diff side is 13 inches. the bottom bar center to center is 21 inches.
chassis bracket to ground is 9 1/2 inches.

 

[rockjeep73]

If you can get better pictures of the housing and chassis brackets so I can see the hole options that would be great. Also what is the crank centerline height.

 

[97singlecab]

chassis side bracket has 7 hole options per bar. center to center of each hole is 3/4"


Axle side bracket has 3 hole options per bar. center to center of each hole is also 3/4"


center line of crank is 23 3/4"

 

[rockjeep73]

Ok one more measurement lol. Bottom hole center on housing bracket to ground.

Does the front of the truck sit higher than the rear? Just curious cause 23 3/4 is pretty high for the motor. I just figured it would be lower being 2wd

 

[rockjeep73]

Well I guess if I looked at the first picture it would have answered my question, truck looks pretty level. I take it that's as low as you can get it?

 

[97singlecab]

The housing bracket bottom hole to ground is 8 1/2" The only way to go lower now is with smaller tires, which I'm looking into but don't have yet. The truck is an 1/8" lower in the front than the back. This is with a 4" drop and 31" tall tires in the front.