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*72longbed* · 03-21-2004, 08:07 PM

On a 67-72 pickup with a two piece driveshaft, is it OK for the rear half shaft to be off center when driving?

Is it more important to have the rear centered, (tires equally spaced in relation to sheetmetal), or, drive shafts in a perfect straight line at drive height?

Who knows the answer????

Thanks,
72longbed

JimKshortstep4x4 · 03-21-2004, 09:06 PM

Since the pinion is offset to the right by approximately 1" the driveshaft is not centered at the rear end. This is true of all trucks
with the 12 bolt rear ends. Not sure on the others, but I would suspect it.

Jim

**FRENCHBLUE72** · 03-21-2004, 09:13 PM

Just checked and jim is right both my blazer and 72 have the shaft off center... Should not create a problem if the shaft is ballanced correctly

*Randy70C-10* · 03-21-2004, 11:02 PM

The shaft should never be in a straight line on anything or the universal joints wouldn't do their job correctly.

SWINGSAX68 · 03-21-2004, 11:10 PM

sorry to butt in
how about on a one peice.

*Randy70C-10* · 03-21-2004, 11:21 PM

Same with a one piece. The pinions were offset on all rear wheel drive cars for this reason.

Longhorn Man · 03-22-2004, 12:17 AM

Not to mention that your rear will move from side to side a little bit as the rear bounces. Look at the pan hard bar and visualize the rear squatting. (Talking coil spring trucks here) The rear has to move side to side.

*72longbed* · 03-22-2004, 12:02 PM

Thanks to all for the input!

Since my truck has a later year, (1974) 14 Bolt full floater, the offset is exaggerated by the unequal axle length that a 14 Bolt has. So I've been checking every measurement to make sure It's not self-destructing the driveline when riding along.

So I guess I'll go back to centering the WHEELS under the truck at ride height rather than having a perfectly straight driveshaft. (Luckily I installed an adjustable panhard bar.)

It does look kinda' funny right now with the rear pushed over to the drivers side about 1".

Thanks again,
72longbed

crazy4chevs · 03-22-2004, 01:21 PM

good to know, I put a 9" under my truck and centered the wheels and the driveline was off center by 1" to the right, had me comcerned. All is well again.

*72longbed* · 03-22-2004, 01:51 PM

Craz,

I noticed you have a four wheel disk setup under your truck, how do you like it? Did you have to use a second proportioning valve or was the stock valve enough? What type of E-brake setup did you go with?

Thanks,
72longbed

crazy4chevs · 03-22-2004, 02:12 PM

My truck isnt on the road yet still in bodywork stages. I used the lincoln rear with factory discs and e-brakes it had the 5 on 5 lug bolt pattern and was only 1" wider overall. I bought a truck power booster,corvette macter cylinder and prop valve new from CPP all setup for 4wheel discs (it comes as a kit). I also bought their e-brake cables.

cdowns · 03-22-2004, 02:23 PM

as stated ofset in the driveshaft is normal the critical thing to be checking for proper operation is your pinion angle and tranny output shaft angle must be the same

*72longbed* · 03-22-2004, 03:01 PM

cdowns,
are those two angles still as critical when you have a fixed carrier bearing between the two?

72

cdowns · 03-22-2004, 05:51 PM

yes the 2 angels should be very close to the same for good operation of the u-joints

03-21-2004, 08:07 PM	#1
72longbed Account Suspended Join Date: Jun 2003 Location: PA Posts: 1,411	Who Knows The Correct Answer?? On a 67-72 pickup with a two piece driveshaft, is it OK for the rear half shaft to be off center when driving? Is it more important to have the rear centered, (tires equally spaced in relation to sheetmetal), or, drive shafts in a perfect straight line at drive height? Who knows the answer???? Thanks, 72longbed

03-21-2004, 09:13 PM	#3
FRENCHBLUE72 PROJECT 7DEUCE Join Date: Dec 2002 Location: GRANTS PASS OR Posts: 21,594	Just checked and jim is right both my blazer and 72 have the shaft off center... Should not create a problem if the shaft is ballanced correctly __________________ GO BIG GREEN GO DUCKS MEMBER #6377 72 k-5 daily driver 6'' lift 35'' 350-350-205 slowly getting rust free. Project "7DEUCE" check out my build http://67-72chevytrucks.com/vboard/s...d.php?t=267665 Tim Powell..R.I.P EastSideLowlife..... R.I.P..

03-21-2004, 11:10 PM	#5
SWINGSAX68 Now the others dig........ Join Date: May 2002 Location: San Antonio, TX Posts: 1,520	sorry to butt in how about on a one peice. __________________ 68 Chevy C10 Stepside Black Primer 78 GMC Longbed White 09 Chevy Silverado Shortbed Granite Blue *LOOKING FOR A 67 4 DOOR IMPALA!!!Just like Sam and Dean Winchester!! 'Cause Mustangs are for p^#$ and you can fit a body in the trunk of a 67 Impala* MEMBER OF THE DRUM BRAKE CLUB Bachelor of Music in Jazz Studies Texas State University-San Marcos, TX Certified Music Educator I hope Mom is up there watching and being my Guardian Angel "I've got a fever.....and the only prescription.....IS MORE COW BELL" -The Legendary: Bruce Dickenson "F#$@ 'em up!!!!!!" -The Legendary: Rogelio Escobar TRUCKY LINKS** http://67-72chevytrucks.com/vboard/s...d.php?t=457750 http://67-72chevytrucks.com/vboard/s...d.php?t=461184 http://67-72chevytrucks.com/vboard/s...d.php?t=472848 http://67-72chevytrucks.com/vboard/s...d.php?t=417541 http://67-72chevytrucks.com/vboard/s...d.php?t=477788

03-22-2004, 12:02 PM	#8
72longbed Account Suspended Join Date: Jun 2003 Location: PA Posts: 1,411	Thanks ALL!! Thanks to all for the input! Since my truck has a later year, (1974) 14 Bolt full floater, the offset is exaggerated by the unequal axle length that a 14 Bolt has. So I've been checking every measurement to make sure It's not self-destructing the driveline when riding along. So I guess I'll go back to centering the WHEELS under the truck at ride height rather than having a perfectly straight driveshaft. (Luckily I installed an adjustable panhard bar.) It does look kinda' funny right now with the rear pushed over to the drivers side about 1". Thanks again, 72longbed

03-22-2004, 01:21 PM	#9
crazy4chevs Registered User Join Date: Oct 2002 Location: Des Moines WA. (Kent, area) Posts: 668	good to know, I put a 9" under my truck and centered the wheels and the driveline was off center by 1" to the right, had me comcerned. All is well again. __________________ 70 chev c10 swb fleet 72 grill, sb 400, 2/4 drop. 68 chev c10 swb fleet Early classic 4/6 drop with 4wheel disc brakes 9"rear 67-8 buckets tilt and A/C Classic GM Truck Club of Washington .

03-21-2004, 09:06 PM	#2
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Since the pinion is offset to the right by approximately 1" the driveshaft is not centered at the rear end. This is true of all trucks with the 12 bolt rear ends. Not sure on the others, but I would suspect it. Jim

03-21-2004, 11:02 PM	#4
Randy70C-10 Account Suspended Join Date: Mar 2001 Location: Virginia Beach, Va. U.S.A. Posts: 15,320	The shaft should never be in a straight line on anything or the universal joints wouldn't do their job correctly.

03-21-2004, 11:21 PM	#6
Randy70C-10 Account Suspended Join Date: Mar 2001 Location: Virginia Beach, Va. U.S.A. Posts: 15,320	Same with a one piece. The pinions were offset on all rear wheel drive cars for this reason.

03-22-2004, 12:17 AM	#7
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Not to mention that your rear will move from side to side a little bit as the rear bounces. Look at the pan hard bar and visualize the rear squatting. (Talking coil spring trucks here) The rear has to move side to side.

03-22-2004, 01:51 PM	#10
72longbed Account Suspended Join Date: Jun 2003 Location: PA Posts: 1,411	4 Wheel Disks Craz, I noticed you have a four wheel disk setup under your truck, how do you like it? Did you have to use a second proportioning valve or was the stock valve enough? What type of E-brake setup did you go with? Thanks, 72longbed

03-22-2004, 02:12 PM	#11
crazy4chevs Registered User Join Date: Oct 2002 Location: Des Moines WA. (Kent, area) Posts: 668	My truck isnt on the road yet still in bodywork stages. I used the lincoln rear with factory discs and e-brakes it had the 5 on 5 lug bolt pattern and was only 1" wider overall. I bought a truck power booster,corvette macter cylinder and prop valve new from CPP all setup for 4wheel discs (it comes as a kit). I also bought their e-brake cables. Attached Images __________________ 70 chev c10 swb fleet 72 grill, sb 400, 2/4 drop. 68 chev c10 swb fleet Early classic 4/6 drop with 4wheel disc brakes 9"rear 67-8 buckets tilt and A/C Classic GM Truck Club of Washington .

03-22-2004, 02:23 PM	#12
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	as stated ofset in the driveshaft is normal the critical thing to be checking for proper operation is your pinion angle and tranny output shaft angle must be the same __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

03-22-2004, 03:01 PM	#13
72longbed Account Suspended Join Date: Jun 2003 Location: PA Posts: 1,411	cdowns cdowns, are those two angles still as critical when you have a fixed carrier bearing between the two? 72

03-22-2004, 05:51 PM	#14
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	yes the 2 angels should be very close to the same for good operation of the u-joints __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY



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