Rear end noise - Page 2 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

71 super · 07-29-2009, 10:10 AM

It is possible that you have already trashed the pinion bearings or at the very least created a burr on the pinion gears. Get a machinist file and clean the edges of the pinion gears. To do this 1st remove the cross shaft in the rear carrier. It is held i place by a 5/16" pin/bolt. Slide the axle shaftS inward after you remove the wheels one at a time, there is a horseshoe type clip that holds the axles in place. Remove the clip with a strong magnet- sometimes when axles are slid in the fall out but not typically and the magnet is nearly fail safe. Slide the axles out into the housing tubes - no need to complely remove. Use 5/8 socket to then remove the carrier saddle bolts and note side and any shims that they might have in them- photograph! Repeat for the other side. Be careful here as the carrier will actually fall out. before it comes out replace the pin/crosshaft that holds the spider gears in place. This will save you some headaches later if spider gears come out with the posi. Now you can clean your pinion gear teeth or go ahead and pull it out to check bearings. The shims for the pinon are located under the lower pinion bearing and can't be removed without a press so if replacing bearings to a machine shop you must go. You should be ble to get numbers off the bearings to order replacements as well as the number for the front seal. When you get new ones have the machine shop press them on using the shims that you already have for the pinion (you will be replacing bearings not the pinion so things should not change. Install a new seal and a crush sleeve. This are available as kits from placs like richmond gear, and randy's ring and pinion. Summit and jegs also sell rebuild kits for $60 to $100 bucks. You will need a pinion depth checker to reinstall as the crush sleeve is a bitc* to crush in a vehicle laying on the ground so you might want a pro to do this especially if you don't have the tools. Here with the parts available the job is about a 2.5 hour job there with the wait and parts availabe (assumption) you will be down a week. Try tightening the pinion nut first. Fyi the torque settings for saddle caps is 55#, back lash (preferred) is .005 to .008 acceptable is .003 to .010. Pinion preload is new 20-25 #, used 5-10 #. Hope this helps and it could always be worse, axle shaft could have broken and/ or ring gear bolts could have sheared and removed themselves automatically through the housing ask me how I know

Good luck with this, you can do it.

**john** · 09-10-2009, 06:13 PM

Is it fixed yet? Any good news?

eightbanger · 09-10-2009, 07:37 PM

Well now...how should i put this? it is and it isn't. I took the advice I was given here and tightened the nut on the pinion yoke further which squeezed the crush sleeve even more on the pinion bearing and this helped remove that excessive in and out slack that I had on the pinion. Doing that left a lot more thread count on the end than had been there before, but I thought what the heck, hooked it all up and took it out for a run and it worked. So It has been successful up to a point, because im left with an obvious and annoying humming sound that comes in at 20mph and then starts to fade away at about 45mph so the bearing/bearings must be shot. I will buy the rebuild kit for it and follow 71 super's how to and get it done right, but for now it will have to do...no long journeys just local trips, it should hold out. I hope.
Thanks for enquiring John.

LONGHAIR · 09-10-2009, 07:57 PM

Quote:

Originally Posted by eightbanger

im left with an obvious and annoying humming sound that comes in at 20mph and then starts to fade away at about 45mph so the bearing/bearings must be shot. I will buy the rebuild kit for it and follow 71 super's how to and get it done right, but for now it will have to do...no long journeys just local trips, it should hold out. I hope.
Thanks for enquiring John.

Those gears are SHOT, plain and simple. The humming noise is the gears themselves, though the pinion bearings are definately killed too. A "rebuild kit" isn't going to help you a bit w/o a new ring and pinion set. This is rather serious surgery, best left to a professional.

eightbanger · 09-11-2009, 03:25 AM

Don't beat about the bush LONGHAIR, I can take it, give it to me straight

I was hopeing that the gears were not affected, I curse the day my d/s cut loose.

07-29-2009, 10:10 AM	#26
71 super Registered User Join Date: Sep 2005 Location: Canton North carolina Posts: 3,080	Re: Rear end noise It is possible that you have already trashed the pinion bearings or at the very least created a burr on the pinion gears. Get a machinist file and clean the edges of the pinion gears. To do this 1st remove the cross shaft in the rear carrier. It is held i place by a 5/16" pin/bolt. Slide the axle shaftS inward after you remove the wheels one at a time, there is a horseshoe type clip that holds the axles in place. Remove the clip with a strong magnet- sometimes when axles are slid in the fall out but not typically and the magnet is nearly fail safe. Slide the axles out into the housing tubes - no need to complely remove. Use 5/8 socket to then remove the carrier saddle bolts and note side and any shims that they might have in them- photograph! Repeat for the other side. Be careful here as the carrier will actually fall out. before it comes out replace the pin/crosshaft that holds the spider gears in place. This will save you some headaches later if spider gears come out with the posi. Now you can clean your pinion gear teeth or go ahead and pull it out to check bearings. The shims for the pinon are located under the lower pinion bearing and can't be removed without a press so if replacing bearings to a machine shop you must go. You should be ble to get numbers off the bearings to order replacements as well as the number for the front seal. When you get new ones have the machine shop press them on using the shims that you already have for the pinion (you will be replacing bearings not the pinion so things should not change. Install a new seal and a crush sleeve. This are available as kits from placs like richmond gear, and randy's ring and pinion. Summit and jegs also sell rebuild kits for $60 to $100 bucks. You will need a pinion depth checker to reinstall as the crush sleeve is a bitc* to crush in a vehicle laying on the ground so you might want a pro to do this especially if you don't have the tools. Here with the parts available the job is about a 2.5 hour job there with the wait and parts availabe (assumption) you will be down a week. Try tightening the pinion nut first. Fyi the torque settings for saddle caps is 55#, back lash (preferred) is .005 to .008 acceptable is .003 to .010. Pinion preload is new 20-25 #, used 5-10 #. Hope this helps and it could always be worse, axle shaft could have broken and/ or ring gear bolts could have sheared and removed themselves automatically through the housing ask me how I know Good luck with this, you can do it. __________________ 67 blue step side- bb 68 gold and white swb cst anniversary 68 custom swb hot rod Ls swap 69 swb cst 6 cylinder/ overdrive 69 black/black cst bb swb 70 orange and white cst Canada built truck swb bb 71 black and white super swb bb 71 red and white super swb 72 green and white super swb 4x4 62 nova wagon 400 series Ls swapped 68 Camaro 327/4 speed- 1 owner, original paint 66 Volkswagen bettle 69 auto stick Volkswagen Beetle

09-10-2009, 06:13 PM	#27
john member #16 Join Date: Dec 1999 Location: Yuba City Ca. Posts: 3,618	Re: Rear end noise Is it fixed yet? Any good news? __________________ john http://67-72chevytrucks.com/vboard/showgroups.php board vendors http://www.flickr.com/photos/1745471...7602865984234/

09-10-2009, 07:37 PM	#28
eightbanger 454 MAKES IT ROAR Join Date: Jan 2008 Location: Essex, U.K Posts: 2,701	Re: Rear end noise Well now...how should i put this? it is and it isn't. I took the advice I was given here and tightened the nut on the pinion yoke further which squeezed the crush sleeve even more on the pinion bearing and this helped remove that excessive in and out slack that I had on the pinion. Doing that left a lot more thread count on the end than had been there before, but I thought what the heck, hooked it all up and took it out for a run and it worked. So It has been successful up to a point, because im left with an obvious and annoying humming sound that comes in at 20mph and then starts to fade away at about 45mph so the bearing/bearings must be shot. I will buy the rebuild kit for it and follow 71 super's how to and get it done right, but for now it will have to do...no long journeys just local trips, it should hold out. I hope. Thanks for enquiring John. __________________ Nigel. An American living in a British body. 1971 Chevy Cheyenne 10 454 "In a time of universal deceit, telling the truth becomes a revolutionary act." - George Orwell "When injustice becomes law, resistance becomes duty" - Thomas Jefferson No more pain. 03.12.60 -- 12.28.10 http://www.youtube.com/Eightbanger

09-11-2009, 03:25 AM	#30
eightbanger 454 MAKES IT ROAR Join Date: Jan 2008 Location: Essex, U.K Posts: 2,701	Re: Rear end noise Don't beat about the bush LONGHAIR, I can take it, give it to me straight I was hopeing that the gears were not affected, I curse the day my d/s cut loose. __________________ Nigel. An American living in a British body. 1971 Chevy Cheyenne 10 454 "In a time of universal deceit, telling the truth becomes a revolutionary act." - George Orwell "When injustice becomes law, resistance becomes duty" - Thomas Jefferson No more pain. 03.12.60 -- 12.28.10 http://www.youtube.com/Eightbanger



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