Driveshaft angle - The 1947 - Present Chevrolet & GMC Truck Message Board Network

minibike · 02-14-2003, 12:34 AM

I just put in my one piece driveshaft, and it appears like there is a slight angle from the right at the rear to the left at the front. I haven't pulled a tape on it yet, but is the driveshaft supposed to be perfectly straight from side to side? The rear has lowering springs (3"), but measuring from the frame to the inner edge of the tire is about the same on both sides (within 1/4")

Thanks,
Greg

Jackal2k9 · 02-14-2003, 12:46 AM

hhmmmm how slight is this angle.... i need to look at mine... mayb your trans mission is moved to one side or your axle mayb? so not the axel. trans? what kind of mounts you have cross memeber? hows it all setup.

tweaked frame.measure frame widths all the way down and make sure its the same then measure "x"'s across symetric areas. make sure thats good.

crazy longhorn · 02-14-2003, 12:57 AM

You might check the diff , to see if the pinion is centered.....Im not sure on the older 12 bolts, but my 69 has a 75 diff(12 bolt) & it appears that the pinion is offset slightly to the right(not centered in the housing)..........crazyL

Brad · 02-14-2003, 02:47 PM

Mine is offset as well.
I've measured from the widest point on tire to frame and aligned rearend using the adjustable tracking bar. I'm pretty sure trans and engine are aligned as well. All this leaves less space on one side of crossmember loop than the other. I only have about an inch on one side of the hole in crossmember.

Mike C · 02-14-2003, 02:59 PM

They should all be offset slightly. Ujoints are not designed to work in a perfectly straight line, but require a little offset in both planes, but as you know, it can be exceeded. 1 deg is minimum and about 5 deg maximum out of phase.

72CustomCamper · 02-14-2003, 03:47 PM

That offset is normal and is EXACTLY why the vehicles were engineered with a split shaft. (that, and to ease body twist during heavy loading)

Shouldn't be a problem though. U-Joints provide flexibility for short term suspension deflection but should never be out of line more than a degree or so during steady state conditions. That is what a CV (constant velocity) joint is for like on your front wheel drive vehicles.

70 Jimmy · 02-14-2003, 03:58 PM

As long as the output shaft (trans) and the input shaft (diff) are parallel in the horizontal and vertical planes, you will be fine. Kinda what was stated before

minibike · 02-14-2003, 06:53 PM

I appreciate all the help. I won't worry about it.

02-14-2003, 12:34 AM	#1
minibike Registered User Join Date: Jun 2002 Location: Lafayette, LA Posts: 500	Driveshaft angle I just put in my one piece driveshaft, and it appears like there is a slight angle from the right at the rear to the left at the front. I haven't pulled a tape on it yet, but is the driveshaft supposed to be perfectly straight from side to side? The rear has lowering springs (3"), but measuring from the frame to the inner edge of the tire is about the same on both sides (within 1/4") Thanks, Greg __________________ 69 SWB LT1/4L60E www.classicplace.com

02-14-2003, 12:46 AM	#2
Jackal2k9 Registered User Join Date: Apr 2002 Location: Katy, Texas Posts: 171	hhmmmm how slight is this angle.... i need to look at mine... mayb your trans mission is moved to one side or your axle mayb? so not the axel. trans? what kind of mounts you have cross memeber? hows it all setup. tweaked frame.measure frame widths all the way down and make sure its the same then measure "x"'s across symetric areas. make sure thats good. Last edited by Jackal2k9; 02-14-2003 at 12:49 AM.

02-14-2003, 12:57 AM	#3
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,402	You might check the diff , to see if the pinion is centered.....Im not sure on the older 12 bolts, but my 69 has a 75 diff(12 bolt) & it appears that the pinion is offset slightly to the right(not centered in the housing)..........crazyL __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

02-14-2003, 02:47 PM	#4
Brad Out of the carpool lane. Join Date: Jan 2000 Location: Clark Co, WA Posts: 5,672	Mine is offset as well. I've measured from the widest point on tire to frame and aligned rearend using the adjustable tracking bar. I'm pretty sure trans and engine are aligned as well. All this leaves less space on one side of crossmember loop than the other. I only have about an inch on one side of the hole in crossmember. __________________ 1968 C-10 SWB, 5.7 Vortec/700R4/3.73 posi, Torch Red 1968 Camaro, 250/Powerglide, all original (No, I'm not gonna drop a 350 in it!...Jeez!) 2000 Honda VFR in the faster yellow! 2008 Husqvarna TE-610 1967 C-10 SWB 'Six Appeal'-Gone but not forgotten...

02-14-2003, 02:59 PM	#5
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,727	They should all be offset slightly. Ujoints are not designed to work in a perfectly straight line, but require a little offset in both planes, but as you know, it can be exceeded. 1 deg is minimum and about 5 deg maximum out of phase. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

02-14-2003, 03:47 PM	#6
72CustomCamper Registered User Join Date: Feb 2003 Location: Bremerton, WA Posts: 86	That offset is normal and is EXACTLY why the vehicles were engineered with a split shaft. (that, and to ease body twist during heavy loading) Shouldn't be a problem though. U-Joints provide flexibility for short term suspension deflection but should never be out of line more than a degree or so during steady state conditions. That is what a CV (constant velocity) joint is for like on your front wheel drive vehicles. __________________ '72 GMC C20, "2500 Super Custom", Custom Camper, New 454 '93 K2500 Suburban, Old 454 (157K)

02-14-2003, 03:58 PM	#7
70 Jimmy aka Crusher, Crushergmc Join Date: Mar 2000 Location: Oregon Posts: 1,834	As long as the output shaft (trans) and the input shaft (diff) are parallel in the horizontal and vertical planes, you will be fine. Kinda what was stated before __________________ "KEEP IT DOWN!" 70 Jimmy 454 2wd 56 GMC Big Window "It's funny till someone gets hurt, then it's freakin' hilarious"

02-14-2003, 06:53 PM	#8
minibike Registered User Join Date: Jun 2002 Location: Lafayette, LA Posts: 500	I appreciate all the help. I won't worry about it. __________________ 69 SWB LT1/4L60E www.classicplace.com



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