Do I need to replace my Drive Shaft Steady Bearing?

[Clyde9]

From: lockman  (Original Message)
Sent: 4/13/2005 11:13 PM

We are about to replace the two rear drive shaft universal joints. The one closest to the center support steady bearing was missing its grease fitting. Even though the fitting was replaced and greased, there is a minor variable growling noise dead amid ship. My question is how do I tell if I need to replace the steady bearing as well or just the U-joints? Any tests? Thanks



From: Boise_Chief1
Sent: 4/14/2005 4:04 AM

There's no good safe way.  If you can find the parts I'd do both.  I'd doubt they'd be expensive.  If you have problems finding parts put up a post.  I found a knowledgeable parts store locally and they have found every part I couldn't get through the regular parts stores.



From: Sea Hag
Sent: 4/14/2005 10:04 AM

I,d suggest replacing the carrier bearing while you have things apart . I got a replacement from NAPA for about $ 30 bucks . the rubber holding the bearing wears out . They also just sell the rubber part but I felt it wasn't worth replacing just part of it . You will destroy the old bearing when you remove the bearing  from the shaft as you have to pound it off or get access to a press . ( there is a lock spacer ring the comes off first ) . You can use a piece of pipe to tape the new bearing and lock ring in place ( I think it was 1 1/4 " pipe ) .  Not worth not replacing it as you will loose yor drive shaft and suffer collateral chassis damage if it fails . Sea Hag



From: denison
Sent: 4/14/2005 10:06 PM

When I took my drive shaft out I checked the center bearing. After all, it was 30 years old and there is no way to re grease it. It still spun smooth and silent, so I did not put a new one on. I had gotten a new old stock bearing just in case, a Dorman 662-015, which I carry as a spare. On the Dorman box were listed other vehicles, and I presume that meant the same 662-015 bearing also fit them, but I'm not sure. They included the 56-78 Ford Trucks, series 100, 250, 350, 400, 3500 & 4000 with manual transmission, as well as Dodge trucks 1/2 ton through 2-1/2 ton series D100 through D600.
On My 400 center bearing assembly, the salient measurements were the inside diameter of the bearing - 1.375?, the distance below the mounting surface ? 2.25?, and the spacing of the two mounting bolts, 6.5?. My drive shaft was 3? diameter. The drive shaft for the early M300s was smaller in diameter, at 2.5?, and the splined shaft where the center support bearing holds it were smaller also. I measured that spline shaft diameter at about 1.250?. That support bearing assembly had the same distance-below-mounting-surface ? 2.25? and space-between-mounting-bolts ?6.5? I presume the bearing is a light press fit on the splines.
I thought I would just get the bearing (thrifty me) , but the parts catalog lists it as one ?assembly?. I got the whole N.O.S. assembly for $30 on ebay. The sellers said they didn?t know what it was.



From: denisondc
Sent: 2/18/2006 3:55 PM


Less than six months after my previous post on this topic, and about 5k miles further along, that center support bearing went bad - and we went from 55 mph to .5 mph. A fearsome vibration even at 2 mph!!
I didn't have the spare with me!
I got one for $12 from the nearest auto parts store (they delivered it to rural MS.) and after a struggle I got the old one hammered off, the new one installed. This was done on a warm sunny afternoon, on the very wide shoulder of a fairly level road. Took me about 2 hours total.