Carrier Bearing Design Issues!

[Ole Greenie]

Hey Folks...I too recently had to replace the carrier bearing on my driveshaft. It was only two years old and broke at the mount. The bearing was still fine and it still looked new.

I discovered that there were two different carriers depending on the truck. The one I used was the round type that looked like it provided little to no support if any! So my questions are:

1) Could I use the better/stronger half moon type carrier in place of the hanging round one? What modifications would have to be done to do this?

2) I was thinking of ditching the two piece DS for a one-piece that I would have made to hold up to the BB motor. Would the undercab cross frame have to be replaced or altered because of the size of the hole for the DS...keeping in mind that I would be going with a larger diameter DS.

3) What have you all done to solve this "weak link?"

Comments and/or suggestions please!!!

Have a great Memorial Day Weekend! FREEDOM IS NOT FREE!!!

[Shaky]

I have no experience with this one, but I was thinking of trying it out:

http://www.iedls.com/Center-Support-...Difference.asp

[Longhorn Man]

with a SWB, you'll have no problems with a one piece shaft.

[Lee H]

I've been running that Inland Empire Driveline support for several years now. Keep eating the aftermarket supports, even with a rebuilt and balanced drive shaft. Bearing was fine, just tore up the bracket.

[Ole Greenie]

Originally Posted by Lee H

I've been running that Inland Empire Driveline support for several years now. Keep eating the aftermarket supports, even with a rebuilt and balanced drive shaft. Bearing was fine, just tore up the bracket.

This is certainly interesting stuff. $133 for the support mount and $45 to have it installed to the DS = $178.

The question is will the stock DS for a 307 motor hold up to 450HP even with the heavy duty center support?

Originally Posted by Longhorn Man

with a SWB, you'll have no problems with a one piece shaft.

I'd like to think so...but I am a bit concerned. Are there any pictures out there for an upgraded increased diameter DS? Optimally, this is the way I'd like to go as it is only $80 more for a one piece DS rated to 1000HP from a local performance machine shop.

What do you think?

[leddzepp]

Originally Posted by Longhorn Man

with a SWB, you'll have no problems with a one piece shaft.

x 2. Been there, done that.

[Longhorn Man]

if you don't have slicks, then a stock one piece, or even a stock 2 piece will hold up. The carrier bearing that you get from the parts store is junk, the ones from a drive shaft shop are generally better. I have no first hand knowledge on the one you are dealing with since I've only had one 1/2 ton and it had a one piece shaft.
There's no reason to get a large diameter 1000 HP proof shaft if you don't even have half that. Plus, there's the fact that horse power doesn't damage the shaft, torque does.
A normal steel shaft is all you need unless you have wide slicks out back.

[Ole Greenie]

Originally Posted by leddzepp

x 2. Been there, done that.

Yea...If I only hed the later style support mount with that crossmember!!!

the pass thru hole in the CM is considerably larger than mine. Mine is half that big! (I looked at the pictures in your build thread.) Yours is a 72 which uses the newer style support and cross member. The 70 and earlier trucks (mine is a 70) have the old style DS support with a much smaller diameter hole for the DS.

[Ole Greenie]

Originally Posted by Longhorn Man

if you don't have slicks, then a stock one piece, or even a stock 2 piece will hold up. The carrier bearing that you get from the parts store is junk, the ones from a drive shaft shop are generally better. I have no first hand knowledge on the one you are dealing with since I've only had one 1/2 ton and it had a one piece shaft.
There's no reason to get a large diameter 1000 HP proof shaft if you don't even have half that. Plus, there's the fact that horse power doesn't damage the shaft, torque does.
A normal steel shaft is all you need unless you have wide slicks out back.

Thanks for that info. Primo. This makes me feel a bit better about the integrity of the DS. Agreed, the stamped steel carriers are pure trash. Design is horrible...which is why GM changed the design 3 years into the production run.

Completely correct...torque is the culprit. Thanks for the realignment It is just that there is no price difference between a "beefier" one and one used in racing applications. So, I figure I might as well go for a stronger designed DS.

This is what I wanted to hear. I would have hated to grind all those rivets off to change the CM. That would have been a PITA.

The only issue I have now is...I hope the shorten job that was done to the front half of the DS when it was changed from a three-speed manual to a 700R4 will hold up as well.

Heck, if it breaks...it breaks! Thanks all for the help!

[Ole Greenie]

Here is a thread with a larger one-piece DS and the clearance issues associated for those of us running the older style crossmember and "hanging" 2-piece DS support

Thanks to USMCChevy! Go Army...Beat Navy!!!

[leddzepp]

Originally Posted by Ole Greenie

Yea...If I only hed the later style support mount with that crossmember!!!

the pass thru hole in the CM is considerably larger than mine. Mine is half that big! (I looked at the pictures in your build thread.) Yours is a 72 which uses the newer style support and cross member. The 70 and earlier trucks (mine is a 70) have the old style DS support with a much smaller diameter hole for the DS.

I was referring to another SWB truck I had, with the one piece shaft. It was HD, and had no problem fitting thru the crsossmember. I also had another 72 with the same hanging type of carrier bearing you are referring to, and the diameter of the x-member hole was the same. I have never been aware of there being any differences in the crossmembers? Maybe I learned something new today

[Shyguy]

I am running a two piece large drive shaft with the stock heavier duty carrier bearing from a '67 3/4 ton truck behind my 454 with a old style 4 speed and it works just fine.

[Longhorn Man]

my 72 3/4 ton burb has the same crossmember as in the photo above, it does have the horse shoe style bearing though. Both my one ton and my old 3/4 ton longhorns had this style too. Like I said, I've never had to deal with the one being discussed on here.

[brad_man_72]

Originally Posted by Ole Greenie

This is certainly interesting stuff. $133 for the support mount and $45 to have it installed to the DS = $178.

The question is will the stock DS for a 307 motor hold up to 450HP even with the heavy duty center support?



I'd like to think so...but I am a bit concerned. Are there any pictures out there for an upgraded increased diameter DS? Optimally, this is the way I'd like to go as it is only $80 more for a one piece DS rated to 1000HP from a local performance machine shop.

What do you think?

a mahine shop is not a driveine shop! A drieshaft ballancer is a large and expensive piee of machinery.

I'm running a 3" 1310 driveshaft I made in my truck. I'm a pro not for the do it yourselfer.

yyou can ad some steel support to the stock style carrier bearing, we do it all of the time. No way would I ever throw down the coin for a billet carrier bearing.

[brad_man_72]

just for reference on how much hp a ds can take we build our stock car shafts out of 2" .083 wall dom tubing and drill a 1.25" hole through the 1310 endyokes. These guys are making over 500 hp. That's the same size tube, yokes and ujoints these trucks use stock.
the length is why a drivehaft needs to be a larger diameter.
aluminum shafts for racing is like aluminum rods ffor racing they must be replaced periodicaly and are usually made of about double wall thickness as steel making for minimal advantage.
I've heard reference to hd driveshafts. What does this mean, I have been building driveshafts for a few years. Alot of people think thicker tubing is better, but it makes a shaft more likely to fail from high rpm.

[ItsRandy]

Originally Posted by Ole Greenie

Hey Folks...I too recently had to replace the carrier bearing on my driveshaft. It was only two years old and broke at the mount. The bearing was still fine and it still looked new.

I discovered that there were two different carriers depending on the truck. The one I used was the round type that looked like it provided little to no support if any! So my questions are:

1) Could I use the better/stronger half moon type carrier in place of the hanging round one? What modifications would have to be done to do this?

2) I was thinking of ditching the two piece DS for a one-piece that I would have made to hold up to the BB motor. Would the undercab cross frame have to be replaced or altered because of the size of the hole for the DS...keeping in mind that I would be going with a larger diameter DS.

3) What have you all done to solve this "weak link?"

Comments and/or suggestions please!!!

Have a great Memorial Day Weekend! FREEDOM IS NOT FREE!!!

Did you lower your truck? How much? Have you checked your drive shaft angles to be sure they are correct? Just replacing the carrier bearing may treat the symptom but not solve the real problem. The center support is just the weak link in the system, just going bigger there may stop that failure but then the next weakest part will start to fail (u-joints, yokes) and cause vibration causing other parts to fail (tail shaft bushings, tail shafts). Check the drive shaft angles, the tool is cheep ($10) and this way you will FIX the problem not throw parts (money) at it.

[NINERS1]

I had the same problem, I changed to the "carrage style" bearing and had held up good so far. cpp sell the kit http://www.classicperform.com/Store/...Truck/CSBC.htm

[Ole Greenie]

Originally Posted by ItsRandy

Did you lower your truck? How much? Have you checked your drive shaft angles to be sure they are correct? Just replacing the carrier bearing may treat the symptom but not solve the real problem. The center support is just the weak link in the system, just going bigger there may stop that failure but then the next weakest part will start to fail (u-joints, yokes) and cause vibration causing other parts to fail (tail shaft bushings, tail shafts). Check the drive shaft angles, the tool is cheep ($10) and this way you will FIX the problem not throw parts (money) at it.

The truck is lowered 3.5" in front and 4" out back so the angle didn't change much if at all. Have not checked the DS angle. I have heard that the angle for the motor and the angle for the diff have to be the same...lines of angle are parallel. Correct?

[70truckguy]

I have a swb and have trashed several carrier bearings. I changed it out for a one-piece made at the local machine shop and haven't had any problems. Mine's factory ride height and has a 700r4, so now the one-piece is pretty short but works great.

[Dark Knight]

Mine also broke. I think that's why my rear wheels locked up when I had my blowout. Maybe the d-shaft got into a bind. Oh well. That's beside the point. I took mine, MIG welded it back together, then welded some 1/8" flat bar to the sides of it and made it kinda triangulated. I then proceeded to take it out and hammer on the throttle, dump the clutch, you know, TRY to break it. So far, it's held up. So, just try beefing it up a bit if you have a welder. Be careful not to catch the rubber on fire though.

[Longhorn Man]

if everything is done right, then it won't matter how much throttle you gove it, nor the speed you run it. If done properly, it only supports the weight of the shaft.

[oldgold70c10]

Originally Posted by Ole Greenie

Yea...If I only hed the later style support mount with that crossmember!!!

the pass thru hole in the CM is considerably larger than mine. Mine is half that big! (I looked at the pictures in your build thread.) Yours is a 72 which uses the newer style support and cross member. The 70 and earlier trucks (mine is a 70) have the old style DS support with a much smaller diameter hole for the DS.

If you look at your 1/2 ton x-member, you'll see the mounting holes for the 3/4 style carrier bearing mounting plate.

[ItsRandy]

Originally Posted by Ole Greenie

The truck is lowered 3.5" in front and 4" out back so the angle didn't change much if at all. Have not checked the DS angle. I have heard that the angle for the motor and the angle for the diff have to be the same...lines of angle are parallel. Correct?

You need to get a baseline centerline from your crank centerline, we will call that 0 deg, carry that centerline through the transmission output shaft. The angle of the shaft in the end of the trans needs to be 1 to 1.5 deg. The centerline of the rearend pinon needs to be at the same angle as the first shaft. When you install the rear shaft the angles on the second shaft will automatically correct. You need at least 1 deg. but no more than 3 deg driveline angle or your driveline parts will vibrate and/or fail. Google Spicer driveline installation or dana...there is a whole bunch of good information there.