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-   -   Off-set Pinion Shaft (http://www.hotrodders.com/forum/off-set-pinion-shaft-158205.html)

dchatcher 05-08-2009 10:47 AM

Off-set Pinion Shaft
 
In the process of aligning my '96 LT1 engine/4L60E tranny with the rear-end ('02 Camaro Limited Slip) for a 1937 Chrysler rod I am building, I just discovered the Pinion shaft is not in the exact center of the rear-end housing. It is off-set to the passenger side about 3/4". Is the best way to move the engine over the same amount (which creates some other space problems for me); or **** the engine in the frame ever so slightly? Does anyone know how the folks at GM handles this problem? Not having the engine square in the frame is my best solution.

cobalt327 05-08-2009 10:55 AM

Quote:

Originally Posted by dchatcher
Is the best way to move the engine over the same amount (which creates some other space problems for me); or **** the engine in the frame ever so slightly?

You do not want to slant the engine (can't say **** "kock"?!? lol) in the chassis. Move either it or the rear end to keep it at 90 degrees.

To do otherwise is an invitation to epic driveline vibration and short U-joint life.

Bummer, I know. :pain:

85406 05-08-2009 12:38 PM

The main thing you want is the pinion and motor/tran center line to be parrallel. The 5\8" - 3\4" offset will not be a problem. It will just insure the universals work. Gm and others do it for a reason.

red65novawagon 05-08-2009 05:17 PM

The trans yoke and pinion yoke must be in perfect alignment or you'll have vibration and eventually worn broken parts and alot sooner than you want. The u-joints are intended to run out of plane in a single direction (up and down) if it tries to run in two it will make an eliptical pattern not circular.

techron 05-08-2009 08:11 PM

i adree with everyone above, and this is the excepted method or way of thinking.

B U T...
just food for thought, EVERY corvette from 63 to 82 has the engine offset 1 1/2 inches, the trans centered and the rear centered. they don't have undue vibration or u joint problems. the factory built them all this way. :D :welcome:

Henry the 32nd 05-08-2009 08:12 PM

Move the engine over that far and keep it parallel. measure many cars and you will find the motor offset to one side to balance weight etc.

red65novawagon 05-09-2009 07:17 AM

In the Corvette the diff center was in a fixed location that did not move up and down that way they could offset the pinion location, still the u-joint can only operate out of plane in a single direction that's why front wheel drive cars use constant velocity joints. If you don't believe me mock every thing up before you weld anything and try to spin the driveshaft then you'll see what I'm talking about.

THERACER 05-09-2009 07:44 AM

when i narrowed my 9" in my pro street nova , i centered it with the engine.
the BUZZ word is parallel ,as noted before.

Frisco 05-09-2009 08:22 AM

Quote:

Originally Posted by dchatcher
In the process of aligning my '96 LT1 engine/4L60E tranny with the rear-end ('02 Camaro Limited Slip) for a 1937 Chrysler rod I am building, I just discovered the Pinion shaft is not in the exact center of the rear-end housing. It is off-set to the passenger side about 3/4". Is the best way to move the engine over the same amount (which creates some other space problems for me); or **** the engine in the frame ever so slightly? Does anyone know how the folks at GM handles this problem? Not having the engine square in the frame is my best solution.

Having the pinion shaft offset is quite normal and to be expected. A Ford 9" has about 1 1/4" offset.

You do NOT have to install the engine off to one side. This is sometimes done (even from the factory) for steering clearance, NOT to align the driveshaft.

You should avoid canting the engine. This will definitely cause premature failure of the u-joints.

The correct alignment is for the engine crankshaft centerline and the centerline of the pinion shaft to be parallel to each other. This is when looking from the side and/or from above.

THERACER 05-09-2009 08:25 AM

yes , PARALLEL

techron 05-10-2009 01:21 AM

Quote:

Originally Posted by red65novawagon
The trans yoke and pinion yoke must be in perfect alignment or you'll have vibration and eventually worn broken parts and alot sooner than you want. The u-joints are intended to run out of plane in a single direction (up and down) if it tries to run in two it will make an eliptical pattern not circular.

not insulting you, but just debateing. but how do the u-joints know they are operating a single direction??? (they have no brains). i,m an old retired corvette mechanic and have known about this koked engine deal for decades.i'm restoring my 64. (it'a body off resto mod) and just for fun, i guy who bought a 65 disk brake car.

,m
and i'm working on on a friends 65 vette.
he was freaked out by the offset of the engine. i told him " your car has been wrecked. then I showed him the engine was offset from the factory. go figure, i'm tired. we went fred stokes ranch

cobalt327 05-10-2009 04:16 PM

A u-joint when working at an angle will have fast and slow portions of its rotation, for lack of a better term. The idea is to have these motions in phase w/each other. If there are more than one out of plane angle, it's easy to visualize how there will be problems.

Whether a 'Vette has this "two planes out of phase" is really a moot point. It is not a desirable thing, and I suspect the engineers of the 'Vette did this for reasons that are not usually encountered- and did the things necessary to quell any damaging vibes/oscillations that will result.

enjenjo 05-10-2009 08:57 PM

Most rear drive GM cars have the engine offset to the right. And most of them have a centered pinion. the angle is a non issue. up and down, side to side, or at 45 degrees, as long as the angle of the joint is less than 7 degrees, and equal but opposite the angle on the second joint, there is no problem.

red65novawagon 05-11-2009 02:22 PM

Just 4 *****s and grins if you have a way to get your car up in the air pull the driveshaft from the rear and bring the shaft down so that it's at two different angles, when it's at two separate planes of travel and you'll quickly understand what I'm talking about. :D

enjenjo 05-11-2009 11:19 PM

If the driveshaft is offset to one side, that would be one angle in a vertical plane. If it's offset up and down that is one angle in a horizintal plane. If it is offset both vertically, and horizontally, it is still one angle, but at 45 degrees to both the vertical, and horizontal, and still measured the same way.


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