Drive shaft support bearing breaking.

['69C-10]

My 71 C10 has a 2 pc drive shaft with a support bearing that is supposedly for trailing arm suspension even though I have leafs. The original one rusted and broke so I replaced it with a new NAPA part. In less than 10 miles the Napa piece came apart where the mounting place is welded to the housing. Any guesses as to if this is a fluke or what is causing these to break?

Original Part



Napa Replacement



Napa Replacement

[stsalvage]

your running the wrong one.That is for the 1960--67 trucks the new ones are different I think i have a pic.But if you want to use that one I might have a easy fix But you might want to take your drive shaft in to have it bounced the first pics are from my 1965 3/4 ton with coil spring but dose not make one difference I will check and see if i have a pic for the other carrier bearing and housing

[Artofdeath]

When driving do you feel any vibration at all? I would think that if it was shaking bad enough to break the bearing holder you would have felt it. Looks like something substantial to cause the carrier to break like that. Anything changed? Pinion angle?

[stsalvage]

the ones for are trucks from 1968 and up look like this this is the bracket the drive shaft all together this gose for 1/2 --1 ton with the slip Joint One peace drive shafts don't have the carrier bearing

['69C-10]

Originally Posted by Artofdeath

When driving do you feel any vibration at all? I would think that if it was shaking bad enough to break the bearing holder you would have felt it. Looks like something substantial to cause the carrier to break like that. Anything changed? Pinion angle?

No vibration at all, not even after the holder broke. Just the sound of the driveshaft scraping against the cross support. I've only had the truck since December, but nothing has changed since I've owned it.

Originally Posted by stsalvage

the ones for are trucks from 1968 and up look like this this is the bracket the drive shaft all together this gose for 1/2 --1 ton with the slip Joint One peace drive shafts don't have the carrier bearing

I've only seen the bearing I have when I've looked up the parts. My shaft doest have the slip joint like the one you show. In full disclosure this is titled as a '71 and I'm told its a '71 cab and frame with '67 nose and bed. The frame was welded to a short bed, for all I know the back half is from something completely different. Either way, I don't have the provisions to mount the one that you have.

Where the bearing sat over the splines..

[Ironangel]

Both my 72's have the type the OP has shown. So you do have the correct carrier bearing. The way both of yours have broken I'm guessing your drive shaft(s) are out of balance and possibly bent. Your not feeling it because the bearing stem is absorbing most of the vibration. Your shafts may also be indexed incorrectly causing or at least contributing to the problem. I would buy a new one and take the whole assembly, both shafts and the bearing to a drive shaft shop and have them balance the whole unit. If you could secure a camera or a phone to take a video of the bearing while you take a short drive I bet you'd see that thing wobble...

[t300]

for what its worth I've gone through 2 napa crappy ones in less than 5000miles. both look and feel like junk right out of the box. reminds me actually i haven't replaced the 2nd one yet...

[HO455]

Please correct me if I have misunderstood you. You are saying the truck was a long bed coil spring truck to start and has been converted to a short bed leaf spring truck? I believe there in lies the problem. The carrier bearing you have is what I know as the 1/2 ton coil spring style. As you drive the drive shaft moves forward and aft as the suspension travels. The coil spring trucks have a limited amount of movement transferred to the drive shaft during normal driving, as the axle is bolted solidly to the swing arms. So GM used cheaper style carrier and driveshaft. (Shocking! I know.) This style of carrier absorbs that limited movement with the rubber surrounding the actual bearing. The leaf spring truck rear axles are subject to twisting as result the amount of driveline movement is greater. On these trucks the carrier is fixed and there is a slip joint in the rear section of the drive shaft to absorb this movement and keep the front half of the drive shaft steady. Your half breed set up means the carrier bearing is being forced back and forth as the axle twists under acceleration and deceleration. Your old carrier was probably well worn when the modification was done and had lots more slop than the new one. (Not to mention where the carrier ended up when the drive shaft was shortened) The new one with no slop still had to move so the mount flexed until it snapped. This problem occurs on bagged trucks that see a much lower and larger range of axle motion.
Photos show my old carrier and its replacement, a new drive shaft with the slip joint and fixed carrier.
I hope this helps. And as always my opinions are subject to peer review.

P.S. I believe that stsalvage's carrier set up is the C20 standard coil spring suspension carrier. Notice it has a slip joint adjacent to the carrier. It may have come on 1/2 tons with HD suspension. Another mystery we will never know the answer to for sure.

[hewittca]

Originally Posted by HO455

...And as always my opinions are subject to peer review.

I have reviewed your opinions and I agree. *subject to further review.

We definitely need more info to help determine which bearing you are supposed to have, given that it sounds like your truck's driveline and suspension setup is composed of stock components but not in its original configuration if it's been shortened.

['69C-10]

First off, thank you all for your time and information. its greatly appreciated as this is getting frustrating.

What I (think I) know about the truck:

I purchased the truck last December from a guy who had bought it 8 mo earlier. He bought the truck as is so doesn't know exactly what the configuration is.

Truck appears to be a 71 cab and frame with 67 clip and bed.
SPID, which I believe is original, shows 71 long bed (127) w/ 350/350 combo and 1G50AC Heavy Rear Spring

Truck currently is a short bed, 400/350 combo. Welds are visible just behind the support where the shaft bearing mounts. The cross support appears to have holes where trailing arms would mount along with the bearing mount that is specified for trailing arm suspension. Truck has leaf spring suspension on it currently. I don't know what this truck had originally, why it has coil spring cross member and bearing mount but leaf springs. The back half of the frame may not even be c10. The only "slip joint" my driveshaft has is at the transmission.

In looking at this picture I remembered that just before the original mount broke it was bent towards the drivers side of the cross member opening.

[demian5]

Shortbed?! I would just go with a 1 piece!

[Artofdeath]

I would check that pinion angle also and I agree with demain5. How long is the driveshaft from tail stock to pig? I'm sure someone smarter than me will chime in on this one but if its not original I would want to make sure it needs the carrier bearing.

That pinion angle in the last two pictures looks like its pointed up.

[BigMike]

Seems a few trucks have issues with these and others never do. I went through 3 "factory" replacement carrier bearings. After the second one went I thought my driveline was bent or something so I took my driveline assembly to Drivelines Inc. here in town & had it gone through. He said there was no issues with it so I just had him install HD U-Joints. About 100 miles later the 3rd CB went. So I went to CPP and bought their HD Aluminum unit. I have had people on here tell me it's this or it's that & they are a waste of money, BUT I have never had another issue with it. Some setups just seem to not like the factory ones. Granted my truck is low but nothing was binding, vibrating or anything else and was still having issues with the CB. I made sure to check the pinion angle which I fixed with a 4 or 6 degree angle shim (been a while so I don't remember which) when I initially dropped it. Now it is bagged & still have no issues. I went through a lot of time trying to figure out the issue before getting the CPP piece..

[HO455]

Your pinon angle is definitely incorrect. The angle of the center u-joint and the aft u-joint need to be the same. Here is a link to a lot of information on the subject. Be sure to follow the links included. The thread is in the 4x4 section but all of the theory is the same just in a different direction. Lowered trucks have the same drive line issues as lifted trucks. With less room.

http://67-72chevytrucks.com/vboard/s...u+joint+angles

[hewittca]

I agree with others above, your pinion angle looks way off, but I bet it doesn't help our perspective that in those pics the bearing mount is already broken. We are able to decipher a few things here, however. You definitely have all the original stock mounting brackets for a leaf sprung truck, so it appears your frame at least was originally leaf. I noticed on your bearing mount bracket that it is held on with bolts. Those were riveted on from factory, so that has been messed with at some point, possibly even swapped from the correct leaf driveshaft mount in order to make that shortbed trailing arm driveshaft/bearing work. As HO455 mentioned above, that bearing isn't meant to handle the fore/aft motion that the leaf springs transfer to the driveshaft.

['69C-10]

Thank you again everyone for your time and information. I'm stuck at work till tomorrow, but will look at angles when I can as that all makes sense. I plan to lower the truck between 4"-6" in the rear so I guess the next step is to figure out if I stay leafs or convert to coils and to adapt this shaft or have a 1 piece made. While the potential causes of this make sense I'm stumped as to why its an issue now, but hasn't been for however long the truck as been converted.

[clay68c10]

You definitely have something weird going on. Looks like the trailing arm rear still has the panhard bar.
I’d switch to trailing arms when you lower it, if you can get the parts cheap.

[Jason Banks]

Seeing your first picture. I may be late, I didn't read the entire thread yet. My 'NEW' carrier bearing started to come apart exactly like yours. It was a freshly balanced and new ujoint driveshaft behind a 250 6cylinder 3OTT truck. I welded it back together and it has been good ever since. The welds that broke were so small.

[GASoline71]

Originally Posted by clay68c10

You definitely have something weird going on. Looks like the trailing arm rear still has the panhard bar.
I’d switch to trailing arms when you lower it, if you can get the parts cheap.

A leaf sprung rig should not have a panhard rod... good catch.

Gary

['69C-10]

Sorry for being MIA. Got a chance to try and check pinion angle the best I could. The yolk on the rear end appears to be pitched up 10.8 degrees, the driveshaft is up towards the trans at 3.5 degrees and the tailshaft appears to be down about 3.5 degrees. The frame measured down towards the front at 1.4 degrees so I assume all of those previous numbers should be adjusted accordingly. I also noticed that the rear end is to the passenger side about .5" and the drive shaft has a noticeable angle to the left heading forward.

On a side note of trying to figure out this mess, I've been looking at lowering options for leafs. A lot have suggested the DJM flip with no notch needed. I currently have 5.25" between the top of the axle tube and the bottom of the frame. If I flipped my axle the frame would be resting on the tube.

This thing gets more frustrating every time I look at it.

[bill3rail]

The replacement hanger bearing looks like it separated and that would probably be a defect in manufacturing.

I recently replaced mine but have not put too many miles on it since.

I hope I do not see that problem...

Bill

['69C-10]

Napa agreed that the part was defective. They new one they gave me is welded much better. I've had it on prolly 50 miles or so and seems good so far.

[BCOWANWHEELS]

my 72 c10 lwb lowered 5-7 goes thru a h/b every year.. so I,am going long tail th350 n 1 piece drive shaft

[BigMike]

Originally Posted by BCOWANWHEELS

my 72 c10 lwb lowered 5-7 goes thru a h/b every year.. so I,am going long tail th350 n 1 piece drive shaft

I went with the aluminum one and have never had an issue since. That was 3-4 years ago!

[BCOWANWHEELS]

yea, that ccp h/b looks nice. at least if / when it goes bad you can still get home