The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 03-10-2010, 01:53 PM   #1
D-Rat
Registered User
 
D-Rat's Avatar
 
Join Date: Nov 2009
Location: Mesa, AZ
Posts: 226
another carrier bearing Q

what are signs of it going bad aside from obvious driveline vibes? Dang truck is too low for me to get under it easily....haha

Am getting some vibration under the truck, and I feel the truck doing the opposite of surging on the freeway...like the brakes are being tapped intermittently almost, and I'm wondering if there could be enough rotational resistance in the carrier bearing to get this feeling, or if the issue is engine related. In other words I can't tell if it's running rough or if the issue is further down the drivetrain. The truck is idling good, has no vacuum leaks that I can find, and the ignition system seems to be in good shape with nearly new wires and HEI. I don't really feel this at lower speeds.

strange thing to ask, I know, but I'm having trouble diagnosing exactly what's happening here
__________________
1970 CST with a screaming 400

www.nissan4wheelers.com
D-Rat is offline   Reply With Quote
Old 03-10-2010, 05:03 PM   #2
trapper68gmc
Registered User
 
trapper68gmc's Avatar
 
Join Date: Mar 2010
Location: Everett, WA
Posts: 7
Re: another carrier bearing Q

I am having the same issue. Mine is making a noise like something is lose as well. I am going to rip it apart this weekend. I described what you did to a mechanic friend of mine and he said he would check the carrier bearings out. My seals are starting to leak too so I think it is time to change it all out anyway.
trapper68gmc is offline   Reply With Quote
Old 03-10-2010, 05:35 PM   #3
CSGAS
optomistic ah-so
 
CSGAS's Avatar
 
Join Date: Mar 2009
Location: Charlotte, NC
Posts: 544
Re: another carrier bearing Q

Only a good look will tell you for sure but some other things that can cause those symptoms include dragging brakes or bearing/seals going bad in the rear end. when you come to a stop, feel the axle centers where your wheels rest on them. They may be warm but if they are hot you should track down that problem and eliminate it.

It could be as simple as backing up in a straight line and stopping hard so the wheel adjusters do their job properly.

Is there a growling noise coming from the vicinity of the center bearing when this happens? I know my bearing doesn't growl but the surrounding rubber is slowly trying to escape, so I will be replacing at least that soon. The only way I know that--is because I can see it.

I also had some shuddering from separating tires a ways back, but that doesn't cause the resistance you describe...until the tire comes apart and wraps around your axle (I headed off that part of the process at least)
__________________
Rubbing is Racin'
Ribbing is Bench Racin'


1970 C-10 lwb Fleetside. Originally 350 2-bbl 3-on-the-tree, m/b, m/w, m/s no a/c. Currently running on a '76 Camaro 305.
CSGAS is offline   Reply With Quote
Old 03-10-2010, 07:28 PM   #4
Old Yeller 1970
DON'T TREAD ON ME
 
Old Yeller 1970's Avatar
 
Join Date: May 2005
Location: Crosby County, TX
Posts: 989
Re: another carrier bearing Q

I'd say that if the rubber around the carrier bearing is all torn up then you have to replace it. You may need to have your drive shaft balanced. I had that done to mine and it took care of all my problems. You may also have a tire out of balance too.
__________________
Old Yeller
Old Yeller 1970 is offline   Reply With Quote
Old 03-11-2010, 12:19 PM   #5
D-Rat
Registered User
 
D-Rat's Avatar
 
Join Date: Nov 2009
Location: Mesa, AZ
Posts: 226
Re: another carrier bearing Q

My DS was rebalanced recently by the PO. I have the receipts, so I think that's good. I'll get under it and check the bearing itself as soon as I have some time in the daylight to do so.

I coasted down an onramp today in neutral but there was no percieved resistance, so I'm thinking this isn't the problem. I think it's in the fuel delivery or spark. I'll be pulling the plugs too when I get the time to see if they're black and sooty, or wet due to a cylinder not firing.

Sometimes diagnosing a problem really sucks. Might be time to ditch the old Holley for a new shiny Edelbrock.
__________________
1970 CST with a screaming 400

www.nissan4wheelers.com
D-Rat is offline   Reply With Quote
Old 03-11-2010, 01:37 PM   #6
Old Yeller 1970
DON'T TREAD ON ME
 
Old Yeller 1970's Avatar
 
Join Date: May 2005
Location: Crosby County, TX
Posts: 989
Re: another carrier bearing Q

Don't ditch the Holley without at least an attempt at a rebuild. They're pretty simple to take apart and you can blow out all the holes with carb cleaner and/or compressed air.

You may also have a bad spark plug wire. Watch it run in the dark and look for sparks arcing to ground or if you're brave enough run your hands over the wires while it's running.
__________________
Old Yeller
Old Yeller 1970 is offline   Reply With Quote
Old 03-11-2010, 04:23 PM   #7
D-Rat
Registered User
 
D-Rat's Avatar
 
Join Date: Nov 2009
Location: Mesa, AZ
Posts: 226
Re: another carrier bearing Q

Yeah, I figured pulling the plugs would tell that story without risking shocking the heck out of myself . The wires are fairly new though...under 12k miles and about 2-3 years old. I checked them pretty closely and they're all in good condition, visibly anyways.
__________________
1970 CST with a screaming 400

www.nissan4wheelers.com
D-Rat is offline   Reply With Quote
Old 03-11-2010, 04:36 PM   #8
splehigh
Registered User
 
splehigh's Avatar
 
Join Date: Nov 2008
Location: Glenville, Pa
Posts: 445
Re: another carrier bearing Q

A couple years ago the my carrier bearing broke where it bolts to the cross member. I guess it broke from flexing right below the mount. I wish I would have taken pics. I was able to limp home with the drive shaft tied up with a piece of rope. Every couple miles the rope would wear through and I would have to stop and tie it up again. Was quite an experience. LOL
splehigh is offline   Reply With Quote
Old 04-26-2010, 06:39 PM   #9
D-Rat
Registered User
 
D-Rat's Avatar
 
Join Date: Nov 2009
Location: Mesa, AZ
Posts: 226
Re: another carrier bearing Q

Welp, that wasn't my problem at the time, but on saturday, my carrier bearing broke. The rubber part is fine...the metal itself broke where it bolts to the crossmember. %#%$! The truck is so low it's a serious PITA to get it lifted far enough to get under it. May just bite the bullet and pay a shop to fix it. Any links to good how to's would be appreciated though before I spend the cash. The thing is almost new too...still nice and shiny.
__________________
1970 CST with a screaming 400

www.nissan4wheelers.com
D-Rat is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 07:35 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com