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Thread: Engine transmission angle?

  1. #1

    Engine transmission angle?

    How attentive should I be to this? The engine and tranny are in now and their at about 5-6* down towards the rearend. I also lowered the truck (4-6) and the rearend is 8-10* up towards the tranny. I don't have the cab or bed on the frame just to make it easier, but I didn't know if it would change these angles or not. Oh, did I mention the engine and tranny are in the frame

  2. #2
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    Find you a truck in a parking lot somewhere and measure the angle of the pan and then duplicate it on your truck. Angle is important, supposedly. I don't know how important because rock crawlers run automatics and nearly stand them on the back bumper without issue.

  3. #3
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    i don't think you're suposed to have no more than a 2* difference between the center line of the yokes. i may be wrong but it sounds like you have a deferential of 13*

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    Quote Originally Posted by racermech View Post
    How attentive should I be to this? The engine and tranny are in now and their at about 5-6* down towards the rearend. I also lowered the truck (4-6) and the rearend is 8-10* up towards the tranny. I don't have the cab or bed on the frame just to make it easier, but I didn't know if it would change these angles or not. Oh, did I mention the engine and tranny are in the frame
    Did you put any shims in between the leaf springs and axle to adjust ur pinion angle??? U will need to do that to keep ur pinion angle lined up right after 6"in drop in the rear

    00' 4.8l 5spd, K&N intake, Granatelli M/A, Shorty headers, Hypertech prg., 160* 2/4 drop

  5. #5
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    yeah, driveshaft angle kills HP but when was the last time you saw the driveshaft angle on a severely lifted 4x4? Those things have scary driveline angles! They'll tilt the rear end to straighten out the pinion angle to the driveshaft but I wonder what happens when they no longer have oil on the bearings since the pinion angle is so pronounced.

  6. #6
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    Quote Originally Posted by RedHeartbeat View Post
    yeah, driveshaft angle kills HP but when was the last time you saw the driveshaft angle on a severely lifted 4x4? Those things have scary driveline angles! They'll tilt the rear end to straighten out the pinion angle to the driveshaft but I wonder what happens when they no longer have oil on the bearings since the pinion angle is so pronounced.
    I know it look like it would tear it all to pieces, there no way its good for them

    00' 4.8l 5spd, K&N intake, Granatelli M/A, Shorty headers, Hypertech prg., 160* 2/4 drop

  7. #7
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    I'd set the pinion 3 degrees low to make sure there's no pinion to driveshaft interference. I leveled my motor and tranny out making adjustments to the crossmember and then set the rear drive shaft 3 degrees low. Trust me, if the pinion is too high it'll hit the driveshaft and knock the heads of the bolts off the pinion. Been there, done that! If you get a good bite on the pavement the pinion is going to the sky unless you have some ladder bars, Cal-tracs or a pinion stop. LOL
    Last edited by NITROUS; 08-02-2007 at 02:27 PM.


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    how exactly do you measure the * prolly something ill wana know for my swap since i have a 4/6 drop aswell

  9. #9
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    Quote Originally Posted by Wtfan18 View Post
    how exactly do you measure the * prolly something ill wana know for my swap since i have a 4/6 drop aswell
    I've done this by positioning the trans & pinion yokes such that the side of each yoke is parallel to the ground (to use somewhat of a flat surface). Placing the angle finder on the yokes will show you an angle measurement. Mine are within 1 degree of each other (4 & 5 degrees - trans & pinion respectively).
    Test-n-Tune (Nov 23, 2008) - 13.65s @ 98mph

  10. #10
    One of the reasons for me asking this is because of the conflicting local information. As far as my rearend angle, I know that's off just by looking at it. But that's understandable due to the 6" drop. This link to s&p is what really got me thinking Driveline Angles . Also, I don't have the cab or bed attached right now, so that will change my engine tranny angle for sure... atleast a little bit. If it doesn't change enough, I was going to do what NITROUS spoke of and put shims/washers under the crossmember. BTW, thanks NITROUS for the help with that a/c idea, it came out great!
    Last edited by racermech; 08-03-2007 at 05:58 PM. Reason: clarification

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