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How do you adjust pinion angle?
#1254276
06/20/12 11:53 AM
06/20/12 11:53 AM
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Joined: Jul 2006
Posts: 4,319
Puyallup, WA
StealthWedge67
OP
master
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OP
master
Joined: Jul 2006
Posts: 4,319
Puyallup, WA
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My car is a 67 B-Body with split mono's and cal trac bars. It appears that in a static position, the pinion is dead straight with the drive line, if not a slight bit pointed up. As I understand it, I want about 2* of downward tilt (in relation to the driveline). Whats the easiest / best way to adjust this. I'm immagining it involves angled shims (????).
LemonWedge - Street heavy / Strip ready - 11.07 @ 120
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Re: How do you adjust pinion angle?
[Re: StealthWedge67]
#1254277
06/20/12 12:14 PM
06/20/12 12:14 PM
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Joined: Jan 2003
Posts: 13,369
Marion, South Carolina [><]
an8sec70cuda
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 13,369
Marion, South Carolina [><]
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Install shims b/t the spring perch on the rearend housing and the leaf spring.
CHIP
'70 hemicuda, 575" Hemi, 727, Dana 60
'69 road runner, 440-6, 18 spline 4 speed, Dana 60
'71 Demon, 340, low gear 904, 8.75
'73 Chrysler New Yorker, 440, 727, 8.75
'90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt
'06 GMC 2500HD LBZ Duramax
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Re: How do you adjust pinion angle?
[Re: Irun5snd8th]
#1254279
06/20/12 12:35 PM
06/20/12 12:35 PM
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Joined: Mar 2009
Posts: 1,058
bigfork mn
dragram440
super stock
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super stock
Joined: Mar 2009
Posts: 1,058
bigfork mn
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I have shims in mine now and it is still tipped up a little. Is this bad for the 60' even though the car seems to be hooking up good? Cut the perches off and start over. 
Last edited by dragram440; 06/20/12 12:36 PM.
67' charger 499 RB
10.57 at 127
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Re: How do you adjust pinion angle?
[Re: dragram440]
#1254280
06/20/12 12:44 PM
06/20/12 12:44 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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You should have nose down on the diff so as you load it it goes to straight under full load... leaf spring cars need more due to wind up on the springs... if its a street car it requires less than a drag car, so about 5* for a street car and about 7* for a drag car 
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Re: How do you adjust pinion angle?
[Re: dartman366]
#1254282
06/20/12 01:19 PM
06/20/12 01:19 PM
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Joined: Sep 2003
Posts: 2,008
Sweet Home Alabama
MRMOPAR622
top fuel
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top fuel
Joined: Sep 2003
Posts: 2,008
Sweet Home Alabama
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When you are doing all of that don't forget to also check the angle of your rear spring shackles drivers side needs to be @ the 10:00 and the passenger side @ the 2:00 o clock position.
"To Be The Man'You Have Got To Beat The Man"
"T/D and Pro-Bracket Racer"
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Re: How do you adjust pinion angle?
[Re: StealthWedge67]
#1254286
06/20/12 03:31 PM
06/20/12 03:31 PM
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Joined: Aug 2003
Posts: 43,218
Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,218
Bend,OR USA
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I would cut the old spring perches off and use new ones, set them on the spring perches, install the U bolts, mock it up so you can rotate the rear end housing and then set pinion angle to where you want it, tack weld the perches to hold them and then reove the rear end so you can weld it on a bench. Take your time on the welding, weld a inch one side and then switch to the other side, do one to one and half inches at a time so you don't warp the axle tubes, brace the perches also 
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: How do you adjust pinion angle?
[Re: Cab_Burge]
#1254290
06/21/12 03:51 AM
06/21/12 03:51 AM
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Joined: Feb 2011
Posts: 4,302
Nebraska
72Swinger
master
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master
Joined: Feb 2011
Posts: 4,302
Nebraska
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Yeah it goes against the Mopar chassis book I know. If your tailshaft is pointing down,they almost always are, in order to make the pinion parallel it will need to be nose up when loaded. When you set it how a driveshaft is supposed to be set with opposing angles at each end it almost always will not look like the diagram in the chassis book unless you're running SS springs. Like Cass said its all about the pinion in relation to the transmission not the pinion in relation to the driveshaft. My car is low and the driveshaft angles upward out of the trans although it still angles down in relation to the ground and my pinion angle is .8 degree nose UP at rest and should be about 3 degrees nose up under load which would put it parallel with the trans. ..... http://www.rosslertrans.com/Pinion%20Angle.htm
Last edited by 72Swinger; 06/21/12 03:52 AM.
Mopar to the bone!!!
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Re: How do you adjust pinion angle?
[Re: Cab_Burge]
#1254291
06/21/12 11:26 AM
06/21/12 11:26 AM
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Joined: Apr 2007
Posts: 782
Minnesota
skep419
super stock
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super stock
Joined: Apr 2007
Posts: 782
Minnesota
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Quote:
Quote:
Quote:
Pinion angle is the relationship between the pinion centerline and the transmission centerline. It is not relative to the ground nor to the angle of the driveshaft.
Ideally, you want the pinion to become parallel to the transmission under a load, so you point the pinion downward a few degrees when the vehicle is resting on its suspension to compensate for pinion wind-up.
In other words, make the pinion parallel to the transmission as a base line, then roll the pinion downward 2-4 degrees and weld the perches. This is how a 2 joint driveshaft is designed to work.
What he said^^^^ you want opposing u joint angles under full power so if the trans is 2 degrees down you want the diff 2 degrees up under load.
 What do you mean by "two degrees up"?
when you mash the gas the diff is going to travel upwards. If the trans is 2 deg down and there is 4 deg of travel that the diff is going to move (always up)than the diff needs to end its travel at 2 deg up. -2 plus +2 equals zero (parallel)
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Re: How do you adjust pinion angle?
[Re: 72Swinger]
#1254292
06/21/12 02:57 PM
06/21/12 02:57 PM
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Joined: Aug 2003
Posts: 43,218
Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,218
Bend,OR USA
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Quote:
Yeah it goes against the Mopar chassis book I know. If your tailshaft is pointing down,they almost always are, in order to make the pinion parallel it will need to be nose up when loaded. When you set it how a driveshaft is supposed to be set with opposing angles at each end it almost always will not look like the diagram in the chassis book unless you're running SS springs. Like Cass said its all about the pinion in relation to the transmission not the pinion in relation to the driveshaft. My car is low and the driveshaft angles upward out of the trans although it still angles down in relation to the ground and my pinion angle is .8 degree nose UP at rest and should be about 3 degrees nose up under load which would put it parallel with the trans. ..... http://www.rosslertrans.com/Pinion%20Angle.htm
I completely disagree with the Rossler charts, Mopar engineers, more than one engineer  ) spent countless hours researching and developing the results printed about setting the Moapr drag racing chassis up WITH leaf springs back in the day, 1962 to 1973 or so A standard Mopar A,B, E body will work very well set up using the Mopar bible on a leaf spring car, a ladder bar or four link leaf spring car with a floater or slider will work very well with 1 to 2 degrees nose down in relation to the dirve shaft, the pinion angle is not dependent on nor should it be set up off of or on the trans angle, especailly on a drag car that is set up for a lot of upward front and rear suspension travel   A tube chassis car is a completely different animal than a standard Unibody Mopar car  All U joints need a difference in angle to operate, it doesn't matter if it is up, down or sideways, it needs the angle to make the needle bearings rotate around the shafts and inside the bearing cups instead of sitting still flattening them out like they would if the pinion shaft and driveshafts where perfectly aligned all the time BTW, one of the first ladder bar cars I drove had negative pinion angle, probally right at 2 degrees nose up in relation to the drive shaft angle, I reset it so it had two degrees nose down in relation to the drive shaft, which was on a up angle to the trans, the trans was higher in the chassis than the pinion shaft was in relation to the ground. The stupid car ran exactly the same 60 ft. times and all the rest of the way down the track where same, my mind felt better though  It never had a driveshaft or U joint issue after that  
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: How do you adjust pinion angle?
[Re: Cab_Burge]
#1254293
06/21/12 03:06 PM
06/21/12 03:06 PM
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Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
Quote:
Yeah it goes against the Mopar chassis book I know. If your tailshaft is pointing down,they almost always are, in order to make the pinion parallel it will need to be nose up when loaded. When you set it how a driveshaft is supposed to be set with opposing angles at each end it almost always will not look like the diagram in the chassis book unless you're running SS springs. Like Cass said its all about the pinion in relation to the transmission not the pinion in relation to the driveshaft. My car is low and the driveshaft angles upward out of the trans although it still angles down in relation to the ground and my pinion angle is .8 degree nose UP at rest and should be about 3 degrees nose up under load which would put it parallel with the trans. ..... http://www.rosslertrans.com/Pinion%20Angle.htm
I completely disagree with the Rossler charts, Mopar engineers, more than one engineer ) spent countless hours researching and developing the results printed about setting the Moapr drag racing chassis up WITH leaf springs back in the day, 1962 to 1973 or so A standard Mopar A,B, E body will work very well set up using the Mopar bible on a leaf spring car, a ladder bar or four link leaf spring car with a floater or slider will work very well with 1 to 2 degrees nose down in relation to the dirve shaft, the pinion angle is not dependent on nor should it be set up off of or on the trans angle, especailly on a drag car that is set up for a lot of upward front and rear suspension travel A tube chassis car is a completely different animal than a standard Unibody Mopar car All U joints need a difference in angle to operate, it doesn't matter if it is up, down or sideways, it needs the angle to make the needle bearings rotate around the shafts and inside the bearing cups instead of sitting still flattening them out like they would if the pinion shaft and driveshafts where perfectly aligned all the time BTW, one of the first ladder bar cars I drove had negative pinion angle, probally right at 2 degrees nose up in relation to the drive shaft angle, I reset it so it had two degrees nose down in relation to the drive shaft, which was on a up angle to the trans, the trans was higher in the chassis than the pinion shaft was in relation to the ground. The stupid car ran exactly the same 60 ft. times and all the rest of the way down the track where same, my mind felt better though It never had a driveshaft or U joint issue after that
I'm with you Cab... the rear end is constantly moving
so how can the 2 U-joints be equal at all times..
granted when I build a chassis I line the centerline
of the engine/trans up with the centerline of the pinion
with it at zero to the driveline then I roll the pinion
down X dergees for the style of rear suspension....
I hate to get involved in this question... there are
the 2 theories to it and no one agrees with the other
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Re: How do you adjust pinion angle?
[Re: MR_P_BODY]
#1254294
06/21/12 04:42 PM
06/21/12 04:42 PM
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Joined: Jan 2003
Posts: 8,016
Polson, MT
DoctorDiff
master
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master
Joined: Jan 2003
Posts: 8,016
Polson, MT
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Because the front and rear joints are NEVER equal at all times, we must find a happy medium to set the pinion angle.
This is why you can't blindly follow the Mopar Chassis manual, as the section on pinion angle is just a reprint from a '68 B-body shop manual where all values were already known. What happens when you raise or lower the suspension and/or transmission, or significantly alter the power-train angle?
For example, if you used the Mopar Chassis manual to set the pinion angle of a rearend mounted higher than the transmission, the driveshaft would bind.
Please explain why the pinion should not run parallel to the transmission when the vehicle is under power? Once again, I must stress "parallel" does not mean "pointing at each other".
In addition, 2 joint driveshafts are always set up this way from the factory. If you measure a stock A,B or E body, you will find the static pinion angle is 2 degrees negative relative to the transmission center-line.
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Re: How do you adjust pinion angle?
[Re: DoctorDiff]
#1254295
06/22/12 07:51 AM
06/22/12 07:51 AM
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Joined: Mar 2006
Posts: 9,910
Eighty Four, PA
B G Racing
master
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master
Joined: Mar 2006
Posts: 9,910
Eighty Four, PA
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Point the pinion at the trans tailshaft weather it's higher or lower than the trans.Set the angle in relation to the shaft angle. SS springs-4to 6 degrees negative of the shaft angle ladder bar-2 degrees negative four link-1 degree nagative We been doing it this way forever and never had any issue with drive train componants.We do all types of race cars from stock to blowen chassis cars. We don't care what anyone diagrams the process as,we do what works in the real world.Everything else is too confusing and open to interpatation and "pinion opinion" 
Last edited by B G Racing; 06/22/12 07:52 AM.
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Tapered shims and Jegs and Summit have lots of them. Just did this on my brothers car two weeks ago and it makes a big difference when you get the angle correct on a leaf spring car. 
