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Re: Driveline angles [Re: Cab_Burge] #1707905
12/10/14 06:01 PM
12/10/14 06:01 PM
Joined: Jan 2003
Posts: 16,376
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dogdays Offline
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Posts: 16,376
Your other question was pinion snubbers. Nancy Reagan said it best, "Just say NO!" to pinion snubbers. They are a cheap crutch that often does more harm than good. Cal-Tracs or similar are the preferred method at least to me.

R.

Re: Driveline angles [Re: dogdays] #1707906
12/10/14 08:38 PM
12/10/14 08:38 PM
Joined: Jan 2003
Posts: 27,421
Balt. Md
3
383man Offline
Too Many Posts
383man  Offline
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Posts: 27,421
Balt. Md
I have seen alot of fighting on here when pinion angle comes atleast once a year. And it can be very confusing. I try to make it as simple as I can. Most muscle cars most of us will work on will usually have the rear diff lower then the trans and all we want is the eng/trans centerline paralell with the rear diff/pinion centerline under power but not the same centerline. And most of the time the pinion centerline is lower then the trans centerline as it has been on the muscle cars I worked on so the driveshaft will be lower at the pinion then at the trans which gives some angle to the U-joints so they work and lube themselfs. Just figure if the eng/trans centerline is 0 then on a normal leafspring car that is not raced I would most likely set it about 2 down so when on the gas it should be abbout 0 like the trans and give the driveshaft U-joints the angle they need. But you have to consider the cars suspension and if its a race car as some pinions with the trans at 0 may need to be 4 to 6 down but you have to drive and test the car when done to check for vibration and may have to adjust if the suspension does or does not move the pinion as much as we thought on the gas. Not all cars and trucks will use the same setting but to me you just have to remember you are looking to have the eng/trans and the pinion centerlines the paralell but not the same line as your on the gas. Ron

Re: Driveline angles [Re: Cab_Burge] #1707907
12/10/14 09:37 PM
12/10/14 09:37 PM
Joined: Jan 2005
Posts: 3,699
Newport, Mi
Evil Spirit Offline
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Evil Spirit  Offline
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Posts: 3,699
Newport, Mi
Quote:

The u joints don't know the difference in angles from left to right and from up and down, the rear U joint and tranny yokes will know when overly misaligned

stressed I would never have a upside down V angle (The pinion pointed up and the drivesahft pointed down) between the pinion angle and driveshaft angles when sitting still, NEVER




Since you are correct in stating the u-joint doesn't know left/right/up/down - here's a sloppy chart to show some scenarios. All are viewed from side and referenced to ground.

Top one is engine level, u-joint 4*^,(driveshaft 4* dn) u-joint 4*v, pinion level.
Next is engine 2* dn, u-joints 2*^,(driveshaft 4*dn) u-joint 2*v, pinion 2*up.
Next is engine level, u-joints 2*v, (driveshaft 4* up) u-joint 2*^, pinion level.
Bottom is engine 2* dn, u-joints 4*v, (driveshaft 4* up) u-joint 4*^, pinion 2*up.

All scenarios leave the engine/trans and the pinion centerline parallel . Top 2 are typical street car - bottom 2 are more chassis/big tire oriented.

And again - these are UNDER LOAD scenarios - how much more the pinion needs to start out pointed down from these figures vary by suspension type - could be anywhere from 1-7*.

8357942-Angles.jpg (80 downloads)

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Re: Driveline angles [Re: Evil Spirit] #1707908
12/11/14 03:23 AM
12/11/14 03:23 AM
Joined: Aug 2003
Posts: 43,007
Bend,OR USA
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Cab_Burge Offline
I Win
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Joined: Aug 2003
Posts: 43,007
Bend,OR USA
Quote:

Quote:

The u joints don't know the difference in angles from left to right and from up and down, the rear U joint and tranny yokes will know when overly misaligned

stressed I would never have a upside down V angle (The pinion pointed up and the drivesahft pointed down) between the pinion angle and driveshaft angles when sitting still, NEVER




Since you are correct in stating the u-joint doesn't know left/right/up/down - here's a sloppy chart to show some scenarios. All are viewed from side and referenced to ground.

Top one is engine level, u-joint 4*^,(driveshaft 4* dn) u-joint 4*v, pinion level.
Next is engine 2* dn, u-joints 2*^,(driveshaft 4*dn) u-joint 2*v, pinion 2*up.
Next is engine level, u-joints 2*v, (driveshaft 4* up) u-joint 2*^, pinion level.
Bottom is engine 2* dn, u-joints 4*v, (driveshaft 4* up) u-joint 4*^, pinion 2*up.

All scenarios leave the engine/trans and the pinion centerline parallel . Top 2 are typical street car - bottom 2 are more chassis/big tire oriented.

And again - these are UNDER LOAD scenarios - how much more the pinion needs to start out pointed down from these figures vary by suspension type - could be anywhere from 1-7*.


Why would anyone, epscially a drag or road racer want to set thier rear ends up like the bottom two are I would lower the pinion angle down so it had at least two or more degrees difference(than the drivshaft angles) at static and maybe move it down more after trying that, more is better sometimes to start with, epsecailly on leaf spring cars The pinion shaft will always try rotate up under acceleraton, correct


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Re: Driveline angles [Re: Cab_Burge] #1707909
12/11/14 04:10 AM
12/11/14 04:10 AM
Joined: Jan 2005
Posts: 3,699
Newport, Mi
Evil Spirit Offline
master
Evil Spirit  Offline
master

Joined: Jan 2005
Posts: 3,699
Newport, Mi
Quote:

Quote:

Quote:

The u joints don't know the difference in angles from left to right and from up and down, the rear U joint and tranny yokes will know when overly misaligned

stressed I would never have a upside down V angle (The pinion pointed up and the drivesahft pointed down) between the pinion angle and driveshaft angles when sitting still, NEVER




Since you are correct in stating the u-joint doesn't know left/right/up/down - here's a sloppy chart to show some scenarios. All are viewed from side and referenced to ground.

Top one is engine level, u-joint 4*^,(driveshaft 4* dn) u-joint 4*v, pinion level.
Next is engine 2* dn, u-joints 2*^,(driveshaft 4*dn) u-joint 2*v, pinion 2*up.
Next is engine level, u-joints 2*v, (driveshaft 4* up) u-joint 2*^, pinion level.
Bottom is engine 2* dn, u-joints 4*v, (driveshaft 4* up) u-joint 4*^, pinion 2*up.

All scenarios leave the engine/trans and the pinion centerline parallel . Top 2 are typical street car - bottom 2 are more chassis/big tire oriented.

And again - these are UNDER LOAD scenarios - how much more the pinion needs to start out pointed down from these figures vary by suspension type - could be anywhere from 1-7*.


Why would anyone, epscially a drag or road racer want to set thier rear ends up like the bottom two are I would lower the pinion angle down so it had at least two or more degrees difference(than the drivshaft angles) at static and maybe move it down more after trying that, more is better sometimes to start with, epsecailly on leaf spring cars The pinion shaft will always try rotate up under acceleraton, correct




Why would anyone, epscially a drag or road racer want to set thier rear ends up like the bottom two are These are dictated by the engine/trans installed height and the diameter of the tires - so would YOU raise the engine, or put smaller tires on to "correct" this? I would lower the pinion angle down so it had at least two or more degrees difference(than the drivshaft angles) at static and maybe move it down more after trying that, more is better sometimes to start with, epsecailly on leaf spring cars. READ where I said the figures were (Big words, sound them out) UNDER LOAD, and 1-7* additional pinion angle would be needed, according to suspension. Not to mention that the two lower examples would likely be big tire chassis cars that wouldn't likely have leaf springs.


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Factory trained Slinky rewinder.........
Re: Driveline angles [Re: Cab_Burge] #1707910
12/11/14 01:05 PM
12/11/14 01:05 PM
Joined: Jan 2003
Posts: 8,016
Polson, MT
DoctorDiff Offline
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Polson, MT
Pinion angle is easy to understand once you realize the pinion should become PARALLEL to the transmission when the vehicle is under power.

This is true regardless if the rearend is mounted higher or lower than the engine.

Re: Driveline angles [Re: DoctorDiff] #1707911
12/11/14 02:04 PM
12/11/14 02:04 PM
Joined: Jan 2005
Posts: 3,699
Newport, Mi
Evil Spirit Offline
master
Evil Spirit  Offline
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Joined: Jan 2005
Posts: 3,699
Newport, Mi
Quote:

Pinion angle is easy to understand once you realize the pinion should become PARALLEL to the transmission when the vehicle is under power.

This is true regardless if the rearend is mounted higher or lower than the engine.




Obviously much easier for some of us to realize than others.


Free advice and worth every penny...
Factory trained Slinky rewinder.........
Re: Driveline angles [Re: Evil Spirit] #1707912
12/11/14 02:16 PM
12/11/14 02:16 PM
Joined: Jul 2007
Posts: 11,836
Florida
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mopar346 Offline
Let me tell ya about fat chicks!
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