Need help with pinion angle - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jcblue · 05-10-2015, 06:43 PM

I need to measure for a one piece driveshaft but assume I should correct the pinion angle first.. This is a short wheelbase truck if it makes a difference.. I measured the angles and this is what I came up with.. At the tail shaft 4 degrees down toward the floor.. Pinion is 8 degrees up. A 12 degree difference seems extreme, have I measured wrong? Btw the truck is lowered 5/7. Spindle and springs/ springs and blocks.. Thanks for any info.

hugger6933 · 05-10-2015, 08:25 PM

12 Degrees does seem excessive I would think that is about 8 to many in total and 4 even sounds a bit high to me. That may cause a drive line harmonic situation with that much angle but I'm more a paint guy so maybe someone else will speak up. Jim

GMaholic · 05-10-2015, 08:44 PM

If the transmission yoke is 4 degrees down, the pinion should be 4 degrees up. If they are too far out of phase, a bad vibrations will take over.. Try this link.....

https://www.google.com/search?q=gm+s...0CCQQsAQ&dpr=1

**davischevy** · 05-10-2015, 08:45 PM

Do a search on here for pinion angle. You will get some valuable info including drawings. Pictures are always good.

In a nutshell, if you project a line form the output on the tranny rearward, and a line from the pinion forward, the two lines should be parrallel.

jcblue · 05-10-2015, 08:50 PM

That being said, a 4 degree shim will correct my angle?

GMaholic · 05-10-2015, 08:54 PM

as long as both angles are relatively even, they will run in phase ok, say 3 degrees down, and the rear pinion is 3 degrees up, for instance, .................or 8 down and 8 degrees up. exactly like davischevy stated, and look at the attached sketches I sent .

jcblue · 05-10-2015, 09:14 PM

Thank you for the info guys.. Helped a lot..

geezer#99 · 05-10-2015, 10:14 PM

http://www2.dana.com/pdf/J3311-1-DSSP.pdf

http://www.drivetrain.com/parts_cata..._problems.html

hamjet · 05-11-2015, 06:54 AM

http://www.macsmotorcitygarage.com/2...e-and-phasing/ Heres an interesting site .......

**davischevy** · 05-11-2015, 09:37 PM

I should have been out there putting another two degree shim in mine instead of telling you what to do.

05-10-2015, 06:43 PM	#1
jcblue Registered User Join Date: Aug 2007 Location: Elkton, ky Posts: 385	Need help with pinion angle I need to measure for a one piece driveshaft but assume I should correct the pinion angle first.. This is a short wheelbase truck if it makes a difference.. I measured the angles and this is what I came up with.. At the tail shaft 4 degrees down toward the floor.. Pinion is 8 degrees up. A 12 degree difference seems extreme, have I measured wrong? Btw the truck is lowered 5/7. Spindle and springs/ springs and blocks.. Thanks for any info.

05-10-2015, 08:25 PM	#2
hugger6933 Registered User Join Date: Oct 2008 Location: Marianna Arkansas Posts: 7,261	Re: Need help with pinion angle 12 Degrees does seem excessive I would think that is about 8 to many in total and 4 even sounds a bit high to me. That may cause a drive line harmonic situation with that much angle but I'm more a paint guy so maybe someone else will speak up. Jim

05-10-2015, 08:44 PM	#3
GMaholic Registered User Join Date: Mar 2015 Location: Maine, NY Posts: 30	Re: Need help with pinion angle If the transmission yoke is 4 degrees down, the pinion should be 4 degrees up. If they are too far out of phase, a bad vibrations will take over.. Try this link..... https://www.google.com/search?q=gm+s...0CCQQsAQ&dpr=1

05-10-2015, 08:45 PM	#4
davischevy Senior Member Join Date: Sep 2008 Location: Harrison, Arkansas Posts: 9,807	Re: Need help with pinion angle Do a search on here for pinion angle. You will get some valuable info including drawings. Pictures are always good. In a nutshell, if you project a line form the output on the tranny rearward, and a line from the pinion forward, the two lines should be parrallel. __________________ other Larry Build thread, Arkansas K10 https://67-72chevytrucks.com/vboard/...=755797&page=5 The ability to speak several languages is an asset, but the ability to keep your mouth shut in any language is priceless.

05-10-2015, 08:50 PM	#5
jcblue Registered User Join Date: Aug 2007 Location: Elkton, ky Posts: 385	Re: Need help with pinion angle That being said, a 4 degree shim will correct my angle?

05-10-2015, 08:54 PM	#6
GMaholic Registered User Join Date: Mar 2015 Location: Maine, NY Posts: 30	Re: Need help with pinion angle as long as both angles are relatively even, they will run in phase ok, say 3 degrees down, and the rear pinion is 3 degrees up, for instance, .................or 8 down and 8 degrees up. exactly like davischevy stated, and look at the attached sketches I sent .

05-10-2015, 09:14 PM	#7
jcblue Registered User Join Date: Aug 2007 Location: Elkton, ky Posts: 385	Re: Need help with pinion angle Thank you for the info guys.. Helped a lot..

05-10-2015, 10:14 PM	#8
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,542	Re: Need help with pinion angle http://www2.dana.com/pdf/J3311-1-DSSP.pdf http://www.drivetrain.com/parts_cata..._problems.html

05-11-2015, 06:54 AM	#9
hamjet Registered User Join Date: Apr 2013 Location: South Westerlo, New York Posts: 1,325	Re: Need help with pinion angle http://www.macsmotorcitygarage.com/2...e-and-phasing/ Heres an interesting site ....... __________________ Thanks, Joe.. 1969 C/10, 348 C.I., 3X2 bbl. V8, 2004r , LWB.

05-11-2015, 09:37 PM	#10
davischevy Senior Member Join Date: Sep 2008 Location: Harrison, Arkansas Posts: 9,807	Re: Need help with pinion angle I should have been out there putting another two degree shim in mine instead of telling you what to do. __________________ other Larry Build thread, Arkansas K10 https://67-72chevytrucks.com/vboard/...=755797&page=5 The ability to speak several languages is an asset, but the ability to keep your mouth shut in any language is priceless.



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