Driveshaft Center Support Bearing????? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

BuckB78GMC · 06-17-2010, 11:27 AM

So, I realized the hard way that my 78 GMC 2WD has a two piece driveshaft. The center support bearing assembly is pretty much toast and is causing a HUGE wogbble when going down the road at anything over 35 mph. So I was under the truck looking at this thing and it looked easy enough to replace. I went to my local Autozone and bought the bearing that their computer says was the right one. As I started taking this thing apart I'm not so sure that the one I bought is the right one. Of course when I entered the infomation about my truck into their online system, I got like a half dozen different part numbers. My local store only had one in stock though so I snagged it. So, what is the secret to getting this thing off of the driveshaft shaft. Is it just pressed on like any other bearing? I gave the old bearing a couple of good strong wacks with a BFH and so far, it's not budging. I don't want to ruin my driveshaft. the rubber on this thing pretty much disintegrated so know I'm down to just the bearing itself left on the driveshaft. Any help with this project would be much appreciated. Thanks. Buck.

BuckB78GMC · 06-17-2010, 06:55 PM

Is this really a very stupid question I am asking here or does none of the 20+ people who have looked at this thread really know how to help me? I have never owned a truck with a center support bearing before. All of my previous trucks just had a one piece rear driveshaft with a slip joint. I am serious about needing help here. I am quite capable of getting this bearing off the DS one way or another but, I'd rather know how to do it right so I don't destroy the DS in the process.

lester622 · 06-17-2010, 07:40 PM

Its a pressed on bearing.

You can take a screw driver and hammer and work it off just take your time and dont mess up the driveshaft or beat the hell out of it. Then press the new one on and your done.

BuckB78GMC · 06-17-2010, 09:16 PM

Thanks for your help Lester,

Buck

ratty 46 · 06-17-2010, 09:36 PM

You should have it pressed off .... but if your into punishment .... used a brass drift to pound it off (via a hammer) & it won't damage the shaft area that it is clued to.

When you reinstall the new one ... place a 75 or 100 watt bulb on the inner ring area & when it starts smoking a bit it's ready to be slipped on the shaft.

If you hit the shaft with air .... that'll cool it off a bit & shrink it up or pack it with ice for an hour or so.

My opinion ....

Ratty 46

78customdeluxe · 06-17-2010, 09:57 PM

If i'm not anywhere that I can use a press or bearing puller(work) I just take it easy and use a heavy hammer, long heavy sleeves, and a good pair of safety glasses and break the outter race of the bearing apart. Then once thats broke off I use an angle grinder and grind through the bearing on the driveshaft being very careful not to nick the shaft and use a punch and just tap the bearing off. Once the bearings off I just get a peice of pipe that will just slide over the shaft and on the inside of the stamped steel "housing" of the bearing and that same heavy hammer that you used to break the old bearing tap the new one on, it will go hard, but like it was said if you find some way to heat the bearing and cool the shaft it will almost fall right on. After you do this once it only takes 10-15 minutes to do it again if you have to

Fixwhataintbroke · 06-18-2010, 12:13 AM

To get the bearing off i just used a stearing wheel puller with a couple wrenches and nuts so as to get a makeshift puller tool.

What i did to get it back on (it was stupid), was to put the bearing in my oven and set it up to 250, and put the driveshaft in a VERY large icebox for an hour. Didnt have to use a press at all to slide it on.

turner15 · 06-18-2010, 12:43 AM

My bearing, "hanger bearing" came complete with the bracket. Didn't to remove it from the bracket. just replaced the bracket with the 2 bolts from up top.

BuckB78GMC · 06-18-2010, 10:59 AM

Thanks for all of the great advice guys. I beat on it carefully for awhile last night. My driveshaft has a cone shaped guard around one side of the bearing so it's really hard to beat on it with anything without damaging said guard. I have access to a press that I can use so I guess I will just have some patience and do it the right way.

BuckB78GMC · 06-21-2010, 12:56 AM

Well, I ended up going and using a proper shop press to get the old bearing off the driveshaft. I promptly found out upon trying to install the new one that it was in fact the wrong one. I took it back to Autozone and got my $37.00 back. Then, went to my friendly neighborhood Parts Plus and not only got the correct bearing assembly but, got it for $17.00. Needless to say I was pretty well jazzed by that. I used the same shop press to press the new bearing on and then greased all of my U-joints and put it back together. My major wobble from the rear is gone. I still have a little bit of a wobble coming from the front end and a little bit of a grinding sound after driving the truck for awhile. I believe when I cleaned and re-packed my front wheel bearings I should have just replaced them. That will be a project for another day, though. Along with needing to replace the rear pinion seal and cleaning up the rear axle.

frog trucker · 07-09-2010, 06:17 PM

Quote:

Originally Posted by Fixwhataintbroke

To get the bearing off i just used a stearing wheel puller with a couple wrenches and nuts so as to get a makeshift puller tool.

What i did to get it back on (it was stupid), was to put the bearing in my oven and set it up to 250, and put the driveshaft in a VERY large icebox for an hour. Didnt have to use a press at all to slide it on.

I'm wondering . . . how did you got the steering wheel puller to pull the bearing?

As for your installation method . . . why do you say it was stupid? Sounds like a great way to put the bearing on!

Fixwhataintbroke · 07-09-2010, 08:18 PM

Quote:

Originally Posted by frog trucker

I'm wondering . . . how did you got the steering wheel puller to pull the bearing?

As for your installation method . . . why do you say it was stupid? Sounds like a great way to put the bearing on!

I guess i should have elaborated a bit on that. I took three threaded rods, 6 nuts, 6 washers, and 3 wrenches. Place a washer and nut onto one side of each of the rods, place the 3 rods with nut and washers through the Puller and use the wrenches to act as a sort of clamp (for lack of better word), place the remaining nuts and washers onto the other end of the three rods to hold the wrenches in place. Then just use the steering wheel puller like normal and it pops right off.

I only say its a bad idea because i burnt myself (lol), bit of a stupid me to be exact.

06-17-2010, 11:27 AM	#1
BuckB78GMC Registered User Join Date: May 2010 Location: Oak Harbor, Wa. Posts: 19	Driveshaft Center Support Bearing????? So, I realized the hard way that my 78 GMC 2WD has a two piece driveshaft. The center support bearing assembly is pretty much toast and is causing a HUGE wogbble when going down the road at anything over 35 mph. So I was under the truck looking at this thing and it looked easy enough to replace. I went to my local Autozone and bought the bearing that their computer says was the right one. As I started taking this thing apart I'm not so sure that the one I bought is the right one. Of course when I entered the infomation about my truck into their online system, I got like a half dozen different part numbers. My local store only had one in stock though so I snagged it. So, what is the secret to getting this thing off of the driveshaft shaft. Is it just pressed on like any other bearing? I gave the old bearing a couple of good strong wacks with a BFH and so far, it's not budging. I don't want to ruin my driveshaft. the rubber on this thing pretty much disintegrated so know I'm down to just the bearing itself left on the driveshaft. Any help with this project would be much appreciated. Thanks. Buck.

06-17-2010, 06:55 PM	#2
BuckB78GMC Registered User Join Date: May 2010 Location: Oak Harbor, Wa. Posts: 19	Re: Driveshaft Center Support Bearing????? Is this really a very stupid question I am asking here or does none of the 20+ people who have looked at this thread really know how to help me? I have never owned a truck with a center support bearing before. All of my previous trucks just had a one piece rear driveshaft with a slip joint. I am serious about needing help here. I am quite capable of getting this bearing off the DS one way or another but, I'd rather know how to do it right so I don't destroy the DS in the process.

06-17-2010, 07:40 PM	#3
lester622 Registered User Join Date: Jan 2008 Location: New Orleans, La. Posts: 229	Re: Driveshaft Center Support Bearing????? Its a pressed on bearing. You can take a screw driver and hammer and work it off just take your time and dont mess up the driveshaft or beat the hell out of it. Then press the new one on and your done.

06-17-2010, 09:16 PM	#4
BuckB78GMC Registered User Join Date: May 2010 Location: Oak Harbor, Wa. Posts: 19	Re: Driveshaft Center Support Bearing????? Thanks for your help Lester, Buck

06-17-2010, 09:36 PM	#5
ratty 46 Registered User Join Date: Jun 2009 Location: Atlanta, Ga. Posts: 1,104	Re: Driveshaft Center Support Bearing????? You should have it pressed off .... but if your into punishment .... used a brass drift to pound it off (via a hammer) & it won't damage the shaft area that it is clued to. When you reinstall the new one ... place a 75 or 100 watt bulb on the inner ring area & when it starts smoking a bit it's ready to be slipped on the shaft. If you hit the shaft with air .... that'll cool it off a bit & shrink it up or pack it with ice for an hour or so. My opinion .... Ratty 46

06-17-2010, 09:57 PM	#6
78customdeluxe Registered User Join Date: Dec 2002 Location: Upper Sandusky Ohio Posts: 72	Re: Driveshaft Center Support Bearing????? If i'm not anywhere that I can use a press or bearing puller(work) I just take it easy and use a heavy hammer, long heavy sleeves, and a good pair of safety glasses and break the outter race of the bearing apart. Then once thats broke off I use an angle grinder and grind through the bearing on the driveshaft being very careful not to nick the shaft and use a punch and just tap the bearing off. Once the bearings off I just get a peice of pipe that will just slide over the shaft and on the inside of the stamped steel "housing" of the bearing and that same heavy hammer that you used to break the old bearing tap the new one on, it will go hard, but like it was said if you find some way to heat the bearing and cool the shaft it will almost fall right on. After you do this once it only takes 10-15 minutes to do it again if you have to __________________ 88 Crewcab Dually 5.9 Cummins, 5306 Eaton 6-speed, converted 4x4 w/52's up front, 90 front clip(parting out) 1986 ElCamino (needs motor) 1970 C30(future service truck for my ag-equipment repair business) 1970 CST10(parting out and partial donor for the '70 C30) 2000 GMC 1500 ext cab sb, z71, 5.3 loaded auto

06-18-2010, 12:13 AM	#7
Fixwhataintbroke Enthusiast Join Date: Jun 2010 Location: Graham, Wa. Posts: 192	Re: Driveshaft Center Support Bearing????? To get the bearing off i just used a stearing wheel puller with a couple wrenches and nuts so as to get a makeshift puller tool. What i did to get it back on (it was stupid), was to put the bearing in my oven and set it up to 250, and put the driveshaft in a VERY large icebox for an hour. Didnt have to use a press at all to slide it on. __________________ - Cole 1979 Chevy C30 w/ carb 454. 1992 Chevy K1500 w/ tbi 350. Sold 1997 Dodge Ram 1500 w/ Magnum 360 Sold "Good judgment comes from experience. Experience comes from poor judgment." - George Washington

06-18-2010, 12:43 AM	#8
turner15 Registered User Join Date: Jan 2007 Location: Toronto Canada Posts: 265	Re: Driveshaft Center Support Bearing????? My bearing, "hanger bearing" came complete with the bracket. Didn't to remove it from the bracket. just replaced the bracket with the 2 bolts from up top.

06-18-2010, 10:59 AM	#9
BuckB78GMC Registered User Join Date: May 2010 Location: Oak Harbor, Wa. Posts: 19	Re: Driveshaft Center Support Bearing????? Thanks for all of the great advice guys. I beat on it carefully for awhile last night. My driveshaft has a cone shaped guard around one side of the bearing so it's really hard to beat on it with anything without damaging said guard. I have access to a press that I can use so I guess I will just have some patience and do it the right way.

06-21-2010, 12:56 AM	#10
BuckB78GMC Registered User Join Date: May 2010 Location: Oak Harbor, Wa. Posts: 19	Re: Driveshaft Center Support Bearing????? Well, I ended up going and using a proper shop press to get the old bearing off the driveshaft. I promptly found out upon trying to install the new one that it was in fact the wrong one. I took it back to Autozone and got my $37.00 back. Then, went to my friendly neighborhood Parts Plus and not only got the correct bearing assembly but, got it for $17.00. Needless to say I was pretty well jazzed by that. I used the same shop press to press the new bearing on and then greased all of my U-joints and put it back together. My major wobble from the rear is gone. I still have a little bit of a wobble coming from the front end and a little bit of a grinding sound after driving the truck for awhile. I believe when I cleaned and re-packed my front wheel bearings I should have just replaced them. That will be a project for another day, though. Along with needing to replace the rear pinion seal and cleaning up the rear axle.

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