Drive shaft center support replacement - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**ScottH** · 08-28-2003, 01:07 PM

Can anyone tell me the best way to replace the center support of the drive shaft on a 2wd lwb? I'm sure there are previous posts on this but search still isn't working.

Thanks.

**COBALT** · 08-28-2003, 05:12 PM

Easy. First, answer this: what kind do you have? There are two types. The lighter "tear drop" shaped one that bolts to the cross member using two 3/8 bolts, or the heavier "U" shaped bearing that bolts perpendicular to the driveshaft to the frame.

slam33 · 08-29-2003, 10:06 AM

I have found 2 things you need to do. Do not remove the bolt that holds the two shafts together, it's a bear to get back in. Second, hang the whole assembly in place and tighten the rear shaft U- joint straps first, then tighten the support bearing mount. You have some play in the mount and if you tighten the mount first you could preload the rubber cushion (pull it back or push it forward in the housing ) when you mount up the rear U-joint.

cdowns · 08-29-2003, 10:25 AM

first thing is to remove the drivshaft assy from the truck, with the driveshaft out and on the ground i like to clean it up with a wire brush then lenghtwise ill paint a line so that when u go to reassemble it everything will be in phase
i suggest you also replace the ujoints when replacing the carrier bearing, you take the little spring retainers out of the middle u joint then using a press or large c-clamp remove the middle u-joint, once you have the 2 shafts seperated the yoke is held in by the 1 bolt in the center remove the yoke then with a BFH drive off the carrier bearing , clean everything then take your new parts and reverse the order to install MAKE SURE THE DRIVESHAFT IS IN PHASE !!!

**COBALT** · 08-29-2003, 02:21 PM

First thing's first though: what kind do you have? Do you have an automatic with a slip yoke, or a manual with a front U-joint?This determines how you'll have to take the driveline out, and to separate the front part of the driveshaft to get the bearing out/in.

When starting this first thing you do is take a white wax pencil and put a mark on the transmission yoke, every yoke in the driveline, and on the pinion yoke on your differential. The driveline has to go back in exactly as it came out. This'll help.

The "tear drop" bearing is a bit of a pain to get off. You'll have to pull the U-joint in front of it to gain access to the bolt that holds the removable yoke in place that sits in front of the bearing. Once the U-joint is removed, and the bolt is taken out then you have to use a socket to pound out the shaft from the removable yoke. From there just cut the boot that holds the bearing suspended in the housing away, and use a simple set of gear pullers to pull the bearing off.

Buy a good quality bearing. I get mine at NAPA. They're about $30. The el-cheap-os aren't worth buying because they'll fail in 6 month's time.

To get the new bearing on the shaft (once you've cleaned it and got it ready to take the new bearing) first I ignore those little disk shaped dust shields. You don't need them with new bearings. I use a piece of 5" steel pipe that fits over the exposed driveshaft end and sits neatly on the inner race of the new bearing. I put a cap on this pipe, and use that to tap the bearing into place.

Then just put the removable yoke back in place (remember to look at where the marks are), install the bolt, and replace the U-joint. Put the driveshaft back under the truck and you're done.

As for replacing the U-joints if it hasn't been done then that's good advice to replace them.

**ScottH** · 08-30-2003, 05:45 PM

Thanks for all the great info. I picked up the truck over the weekend but haven't had time to go underneath yet. So not sure yet what style center support, but it's a 72 C20 402/400 if that helps narrow it down.

heyjoe · 08-30-2003, 08:40 PM

Big emphasis on chalk marks and phase.
How do ya know if the yokes, etc. are in proper position to begin with? What if previous owner didn't worry about such things and now your are left holding the bag, err mis-assembly.

//heyjoe

**COBALT** · 09-01-2003, 04:21 AM

As long as the driveshaft is balanced and you have no vibrations at high RPM, and your seals and U-joints are in good shape.

With that TH400 transmission I'd almost guarantee you have a slip yoke with a tear-drop bearing.

08-28-2003, 01:07 PM	#1
ScottH Senior Member Join Date: Sep 2002 Location: Hampstead, NC Posts: 8,187	Drive shaft center support replacement Can anyone tell me the best way to replace the center support of the drive shaft on a 2wd lwb? I'm sure there are previous posts on this but search still isn't working. Thanks.

08-28-2003, 05:12 PM	#2
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	Easy. First, answer this: what kind do you have? There are two types. The lighter "tear drop" shaped one that bolts to the cross member using two 3/8 bolts, or the heavier "U" shaped bearing that bolts perpendicular to the driveshaft to the frame. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

08-29-2003, 10:06 AM	#3
slam33 Registered User Join Date: Aug 2001 Location: Long Beach, Ca Posts: 1,432	I have found 2 things you need to do. Do not remove the bolt that holds the two shafts together, it's a bear to get back in. Second, hang the whole assembly in place and tighten the rear shaft U- joint straps first, then tighten the support bearing mount. You have some play in the mount and if you tighten the mount first you could preload the rubber cushion (pull it back or push it forward in the housing ) when you mount up the rear U-joint. __________________ 71 LWB 350/350still working on it but it's going tp be sweet. www.geocities.com/stevemau/slam33page.html " TARGET=_blank>http://www.geocities.com/stevemau/slam33page.html?1004806705410 </A>

08-29-2003, 10:25 AM	#4
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	first thing is to remove the drivshaft assy from the truck, with the driveshaft out and on the ground i like to clean it up with a wire brush then lenghtwise ill paint a line so that when u go to reassemble it everything will be in phase i suggest you also replace the ujoints when replacing the carrier bearing, you take the little spring retainers out of the middle u joint then using a press or large c-clamp remove the middle u-joint, once you have the 2 shafts seperated the yoke is held in by the 1 bolt in the center remove the yoke then with a BFH drive off the carrier bearing , clean everything then take your new parts and reverse the order to install MAKE SURE THE DRIVESHAFT IS IN PHASE !!! __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

08-29-2003, 02:21 PM	#5
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	First thing's first though: what kind do you have? Do you have an automatic with a slip yoke, or a manual with a front U-joint?This determines how you'll have to take the driveline out, and to separate the front part of the driveshaft to get the bearing out/in. When starting this first thing you do is take a white wax pencil and put a mark on the transmission yoke, every yoke in the driveline, and on the pinion yoke on your differential. The driveline has to go back in exactly as it came out. This'll help. The "tear drop" bearing is a bit of a pain to get off. You'll have to pull the U-joint in front of it to gain access to the bolt that holds the removable yoke in place that sits in front of the bearing. Once the U-joint is removed, and the bolt is taken out then you have to use a socket to pound out the shaft from the removable yoke. From there just cut the boot that holds the bearing suspended in the housing away, and use a simple set of gear pullers to pull the bearing off. Buy a good quality bearing. I get mine at NAPA. They're about $30. The el-cheap-os aren't worth buying because they'll fail in 6 month's time. To get the new bearing on the shaft (once you've cleaned it and got it ready to take the new bearing) first I ignore those little disk shaped dust shields. You don't need them with new bearings. I use a piece of 5" steel pipe that fits over the exposed driveshaft end and sits neatly on the inner race of the new bearing. I put a cap on this pipe, and use that to tap the bearing into place. Then just put the removable yoke back in place (remember to look at where the marks are), install the bolt, and replace the U-joint. Put the driveshaft back under the truck and you're done. As for replacing the U-joints if it hasn't been done then that's good advice to replace them. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

08-30-2003, 05:45 PM	#6
ScottH Senior Member Join Date: Sep 2002 Location: Hampstead, NC Posts: 8,187	Thanks for all the great info. I picked up the truck over the weekend but haven't had time to go underneath yet. So not sure yet what style center support, but it's a 72 C20 402/400 if that helps narrow it down.

08-30-2003, 08:40 PM	#7
heyjoe Registered User Join Date: Apr 2003 Location: New Orleans area Posts: 198	Big emphasis on chalk marks and phase. How do ya know if the yokes, etc. are in proper position to begin with? What if previous owner didn't worry about such things and now your are left holding the bag, err mis-assembly. //heyjoe __________________ '67 C20 small window Fleetside - 250 inline 6 - 3 on the tree - heavy duty clutch, brakes, rear springs - 17.5 wheels w/bias ply tires - AM radio - heater.

09-01-2003, 04:21 AM	#8
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	As long as the driveshaft is balanced and you have no vibrations at high RPM, and your seals and U-joints are in good shape. With that TH400 transmission I'd almost guarantee you have a slip yoke with a tear-drop bearing. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.



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