So, if you bust your carrier bearing clean off the frame...

[D-Rat]

...on a lowered truck, would you guess the rear portion of the DS is too long? The PO said it had been shortened, but I can't confirm.

[Leviticus]

I have seen them break for no good reason, they are a crap design to begin with. But it could be because of your drop. Is there a much of force pushing on it while it is sitting parked?

[Schwinn68]

wouldn't this be a good time to just switch to a one piece drive shaft? I don't see why gm decided on a two piece drive shaft on shortbed trucks anyways. It seems like a lot of parasitic loss for such a short length. As soon as I swap out my trans(hopefully soon) I'm changing mine out for a one piece aluminum shaft. I'm thinking about buying the rear cross member from CPP to eliminate the stock piece and to allow room for if I end up dropping the truck.

Maybe I'm off base here but I've had plenty of shortbed trucks and they've never had a two piece drive shaft.

[D-Rat]

Originally Posted by Schwinn68

wouldn't this be a good time to just switch to a one piece drive shaft? I don't see why gm decided on a two piece drive shaft on shortbed trucks anyways. It seems like a lot of parasitic loss for such a short length. As soon as I swap out my trans(hopefully soon) I'm changing mine out for a one piece aluminum shaft. I'm thinking about buying the rear cross member from CPP to eliminate the stock piece and to allow room for if I end up dropping the truck.

Maybe I'm off base here but I've had plenty of shortbed trucks and they've never had a two piece drive shaft.

mine's a longbed. But still....seems a one piece would still be fine.

[Hottrucks]

I'm dropped with a c notch and havn't had an issue ( YET) and I didn't shorten mine
now I'm worried??

[junkyardjohn]

Originally Posted by Schwinn68

wouldn't this be a good time to just switch to a one piece drive shaft? I don't see why gm decided on a two piece drive shaft on shortbed trucks anyways. It seems like a lot of parasitic loss for such a short length. As soon as I swap out my trans(hopefully soon) I'm changing mine out for a one piece aluminum shaft. I'm thinking about buying the rear cross member from CPP to eliminate the stock piece and to allow room for if I end up dropping the truck.

Maybe I'm off base here but I've had plenty of shortbed trucks and they've never had a two piece drive shaft.

I'M NOT SURE EXACTLY WHAT "PARASITIC LOSS" MEANS BUT YES GENERAL MOTORS DID PUT 2 PC. REAR DRIVE SHAFTS IN SHORTBED TRUCKS. I'VE BUILT A FEW 500 HP (VERIFIED ON AN ACTUAL DYNO, NOT SOME COMPUTER PROGRAM) BB SHORT FLEETS THAT I LEFT 2 PC DRIVE SHAFT IN. THE AMOUNT OF H.P. & TORQUE THAT YOU LOSE BY DOING SO IS SO MINUTE THAT YOU'LL NEVER FEEL ANY DIFFERENCE. BELIEVE ME... I CHECKED IT OUT EXTENSIVELY & HAVE SEEKED & WAS REWARDED WITH THE EXPERIANCE & KNOWLEDGE OF PEOPLE WHO'VE BEEN DRAG RACING FOR THE LAST 50 YEARS.
GM MADE 2 DIFFERENT STYLE CARRIER BEARINGS, OR MID-SHIFT BEARINGS. I BELIEVE ONE STYLE WAS FOR 67-68 TRUCKS & ONE FOR 69-72 WITH THE LATTER BEING MUCH MUCH MORE STURDY.
PARASITIC LOSS?? MUST BE ONE OF THOSE $3 WORDS US HILLBILLYS HAVE BEEN ABLE TO GET AWAY WITHOUT USING FOR BETTER THAN 50 YEARS. JOHN

[Indyuke]

As the rear end moves up and down it changes the position of the driveline. The carrier bearing is static on the driveline and the carrier bearing housing is bolted firmly to the frame. What provides the flex between the bearing and the housing is just a big rubber bushing which wears out the more it flexes.

The guy who lowered your truck may not have moved the carrier bearing to take the stress out of it like Leviticus said. Or it may be just a poor quality bearing.

The only reason i can see that GM went with a two piece rather than a one piece driveline is for ground clearance. But that doesn't make any sense, as the driveline halves on all the trucks I've seen seem to be more or less perfectly in line with each other. Maybe a longer one is too easily bent... prone to imbalance. They're the skinniest little things compared to the new trucks. And heavy as can be.

[D-Rat]

Indyduke, that is the issue. After getting under and getting a good look, there's a fair amount of angle at the bearing. when there's angle, there's deflection in the Ujoints, and over time, it stress cracked the T shaped mount, and the metal failed. The bearing on there was a Spicer, and it got replaced today with the same.

Questions - how do you move it upward, or does anyone make one with a shorter T on it? The only way I can see to move it up is to modify the crossmember. Going to a U shaped one would require some driveline mods as well as at least some hole drilling to accomodate the bolts.

Another option is removing the blocks in the back and going from a 6" to a 4" drop to ease the angles. I've been thinking about this anyways so I can run a little taller tire to get my speedo closer to being accurate. (current tires are 235/60/15 - I would go to a 70 - about 2" taller) My concern there is would the truck look right if I did that...it would have a little bit of rake to it with the rear end a tick higher. I'm just wondering if this would help significantly.

That carrier bearing only lasted about 6-7k miles before it failed. I expect the new one to do the same if I don't do something.

[Hottrucks]

not sure where the pic is but some guys have flipped the carrier hanger upside down to get a better angle

[D-Rat]

You'd have to make a drop bracket to do that so you have something to bolt it to.

[Hottrucks]

basicly to take out the old rivets and flip the hanger that the carrier bolts to

right now I'm just trying to figure out how much Hp that tiny DS will take