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

teamradrz1 · 07-11-2009, 08:36 PM

I just installed a newly shortened and balanced driveshaft for my 71 K5 Blazer has 3/4 ton axles and he put a 3/4 ton yoke on the driveshaft to match the pumpkin yoke. Looks perfect but I drove the truck home with the original shaft that was too short and everything was OK put the new shaft on and drove down the street fine but as soon as I hit the brakes softley was only going like 20MPH I heard and felt a Vibration sounded like my nobby tires hitting the fender. doesn't do it taking off or traveling down the road but when I use the brakes it's there pretty consistantly. I'll call the shop Monday but wanted to hear any ideas?

**GruntMoanCough** · 07-12-2009, 11:21 PM

Could be related to pinion angle or different yoke?. I dunno.
I suggest talking to your driveshaft guy, I doubt if he'll be pissed, he'll probably be helpful.
Good luck!

teamradrz1 · 07-13-2009, 12:52 AM

Yeah I was just hoping to try a few things to resolve so I don't sound like an idiot if it is something I am doing wrong

Blazer1970 · 07-13-2009, 05:42 AM

How much lift do you have? It sounds like one of the u-joints might be binding when the pinion dips under the braking force. Or maybe the splines are bottoming out in the slip joint.

**special-K** · 07-13-2009, 07:19 AM

The driveshaft should sit center,or close,of the splines when static.It almost sounds like a rear end noise you are describing.But,I`m not hearing it.I`d just go back and ask them to check it out.Don`t say what you think it is.Just tell them what you are telling us and let them assess it.

OLDCHEV4X4 · 07-13-2009, 08:15 AM

I had a simular problem on my motorhome. It turned out that a grease fitting was rubbing the rear yoke, but only under braking. So i removed the rear u joint, and turned it so the grease fitting was facing the front of the vehicle. Fixed.

Skirkpat · 07-13-2009, 10:02 AM

I was always told to index the grease zert whan replacing the u-joint? I was told to make sure that it was being compressed by the rotation, and not "pulled apart" by it. (don't know if it is true, but I do it anyway?) Maybe if you unhook the drive shaft ad spin it 180 degrees in the driveshaft , it might help?

Hoods69BadBowTie · 07-14-2009, 01:23 AM

Quote:

Originally Posted by OLDCHEV4X4

I had a simular problem on my motorhome. It turned out that a grease fitting was rubbing the rear yoke, but only under braking. So i removed the rear u joint, and turned it so the grease fitting was facing the front of the vehicle. Fixed.

I was also thinking the same thing. Remember my buddies old truck had the same problem pretty much and it was a grease fitting that was rubbing but really only happened under braking. Good luck

teamradrz1 · 07-13-2009, 11:08 AM

Thanks guys I'll look into those ideas I'm kinda leaning toward the angle of the pumpkin is there a way to fix that?

teamradrz1 · 07-13-2009, 11:10 AM

When I installed the shaft I pulled it out about 1.5-2 inches to meet the tranny yoke and he messured between the yokes to make the driveshaft length.

Skirkpat · 07-13-2009, 12:29 PM

They make angled shims

teamradrz1 · 07-14-2009, 01:28 AM

OK called the driveline shop this morning and he had me bring in my truck, mile away. We found that the u-joint caps on the inside are hitting the pinion yoke bolt when braking. So he measured my driveshaft degree angle and suggested I get 4 degree steel shims and that would take care of the issue and still be within the correct range of angleto match the transfer case. He told me where I can get them so I'll call them tomorrow I can't imagine them being very expensive.

Eturnit3 · 07-14-2009, 04:11 AM

diy4x has em too if your wanting to shop around.. Also, Im lovin the look of the blazer, that thing gotta thread? Also that's funny, post #2 nailed it

teamradrz1 · 07-14-2009, 11:38 AM

Quote:

Originally Posted by Eturnit3

diy4x has em too if your wanting to shop around.. Also, Im lovin the look of the blazer, that thing gotta thread? Also that's funny, post #2 nailed it

diy4x is that a member or vendor here or a online vendor?

here is the link to my Blazer thread
http://67-72chevytrucks.com/vboard/s...d.php?t=191072

Eturnit3 · 07-14-2009, 04:30 PM

Maybe? www.diy4x.com they just make some cools stuff for our trucks..

teamradrz1 · 07-14-2009, 10:26 PM

bought the shims and the leaf bolt extenders locally for $40 so same price without the $12 to ship but thanks for the info as it gave me a price point.

07-11-2009, 08:36 PM	#1
teamradrz1 Registered User Join Date: Apr 2005 Location: Gresham, OR 97080 Posts: 499	Need help I just installed a newly shortened and balanced driveshaft for my 71 K5 Blazer has 3/4 ton axles and he put a 3/4 ton yoke on the driveshaft to match the pumpkin yoke. Looks perfect but I drove the truck home with the original shaft that was too short and everything was OK put the new shaft on and drove down the street fine but as soon as I hit the brakes softley was only going like 20MPH I heard and felt a Vibration sounded like my nobby tires hitting the fender. doesn't do it taking off or traveling down the road but when I use the brakes it's there pretty consistantly. I'll call the shop Monday but wanted to hear any ideas? __________________ 1971 Chevy Blazer CST 4X4 2012 Camaro 2SS/RS 2007 Avalanche 4X4

07-13-2009, 12:52 AM	#3
teamradrz1 Registered User Join Date: Apr 2005 Location: Gresham, OR 97080 Posts: 499	Re: Need help Yeah I was just hoping to try a few things to resolve so I don't sound like an idiot if it is something I am doing wrong __________________ 1971 Chevy Blazer CST 4X4 2012 Camaro 2SS/RS 2007 Avalanche 4X4

07-13-2009, 05:42 AM	#4
Blazer1970 Registered User Join Date: Dec 1999 Location: Old Mission, MI, USA Posts: 2,507	Re: Need help How much lift do you have? It sounds like one of the u-joints might be binding when the pinion dips under the braking force. Or maybe the splines are bottoming out in the slip joint. __________________ Tim

07-13-2009, 07:19 AM	#5
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,851	Re: Need help The driveshaft should sit center,or close,of the splines when static.It almost sounds like a rear end noise you are describing.But,I`m not hearing it.I`d just go back and ask them to check it out.Don`t say what you think it is.Just tell them what you are telling us and let them assess it. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

07-13-2009, 08:15 AM	#6
OLDCHEV4X4 Registered User Join Date: Apr 2000 Location: Chester County PA, USA Posts: 1,228	Re: Need help I had a simular problem on my motorhome. It turned out that a grease fitting was rubbing the rear yoke, but only under braking. So i removed the rear u joint, and turned it so the grease fitting was facing the front of the vehicle. Fixed. __________________ 72 k/10 short wideside 72 k/5 Blazer 72 K/5 Blazer - obstacle course racer 72 custom/10 8' bed 70 K/5 Blazer 67 C-30 GMC Flat bed 86 GMC K2500 Plow Truck 85 GMC K3500 84 M1008 85 M1008 77 G30 Motor Home 72 Sears 12hp Tractor Glenmoore, Pennsylvania

07-12-2009, 11:21 PM	#2
GruntMoanCough Registered User Join Date: May 2009 Location: Pemberton, BC Posts: 1,075	Re: Need help Could be related to pinion angle or different yoke?. I dunno. I suggest talking to your driveshaft guy, I doubt if he'll be pissed, he'll probably be helpful. Good luck! __________________ My goal in life is to be as good a person as my dog already thinks I am - Unknown

07-13-2009, 10:02 AM	#7
Skirkpat Registered User Join Date: Dec 2008 Location: K.C. Missouri Posts: 1,024	Re: Need help I was always told to index the grease zert whan replacing the u-joint? I was told to make sure that it was being compressed by the rotation, and not "pulled apart" by it. (don't know if it is true, but I do it anyway?) Maybe if you unhook the drive shaft ad spin it 180 degrees in the driveshaft , it might help? __________________ 1969 Short Stepside 1969 4 WD Suburban 1970 1 Ton Dually....Misfit oh, and a 2001 HD 2500, 8.1 Allison Shortbed 4 Door

07-13-2009, 11:08 AM	#9
teamradrz1 Registered User Join Date: Apr 2005 Location: Gresham, OR 97080 Posts: 499	Re: Need help Thanks guys I'll look into those ideas I'm kinda leaning toward the angle of the pumpkin is there a way to fix that? __________________ 1971 Chevy Blazer CST 4X4 2012 Camaro 2SS/RS 2007 Avalanche 4X4

07-13-2009, 11:10 AM	#10
teamradrz1 Registered User Join Date: Apr 2005 Location: Gresham, OR 97080 Posts: 499	Re: Need help When I installed the shaft I pulled it out about 1.5-2 inches to meet the tranny yoke and he messured between the yokes to make the driveshaft length. __________________ 1971 Chevy Blazer CST 4X4 2012 Camaro 2SS/RS 2007 Avalanche 4X4

07-13-2009, 12:29 PM	#11
Skirkpat Registered User Join Date: Dec 2008 Location: K.C. Missouri Posts: 1,024	Re: Need help They make angled shims __________________ 1969 Short Stepside 1969 4 WD Suburban 1970 1 Ton Dually....Misfit oh, and a 2001 HD 2500, 8.1 Allison Shortbed 4 Door

07-14-2009, 01:28 AM	#12
teamradrz1 Registered User Join Date: Apr 2005 Location: Gresham, OR 97080 Posts: 499	Re: Need help OK called the driveline shop this morning and he had me bring in my truck, mile away. We found that the u-joint caps on the inside are hitting the pinion yoke bolt when braking. So he measured my driveshaft degree angle and suggested I get 4 degree steel shims and that would take care of the issue and still be within the correct range of angleto match the transfer case. He told me where I can get them so I'll call them tomorrow I can't imagine them being very expensive. __________________ 1971 Chevy Blazer CST 4X4 2012 Camaro 2SS/RS 2007 Avalanche 4X4

07-14-2009, 04:11 AM	#13
Eturnit3 Bloodied Knuckles Join Date: Jan 2009 Location: Grass Valley CA Posts: 273	Re: Need help diy4x has em too if your wanting to shop around.. Also, Im lovin the look of the blazer, that thing gotta thread? Also that's funny, post #2 nailed it

07-14-2009, 04:30 PM	#15
Eturnit3 Bloodied Knuckles Join Date: Jan 2009 Location: Grass Valley CA Posts: 273	Re: Need help Maybe? www.diy4x.com they just make some cools stuff for our trucks..

07-14-2009, 10:26 PM	#16
teamradrz1 Registered User Join Date: Apr 2005 Location: Gresham, OR 97080 Posts: 499	Re: Need help bought the shims and the leaf bolt extenders locally for $40 so same price without the $12 to ship but thanks for the info as it gave me a price point. __________________ 1971 Chevy Blazer CST 4X4 2012 Camaro 2SS/RS 2007 Avalanche 4X4

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