Driveshaft concerns/questions

[Sport/Truck]

I was under the truck today (luckily) and noticed my center bearing is going out.
I'm wondering what direction I should take this project now, and would like pro's & con's for both one-piece or two-piece driveshafts.

The truck is lowered, but would like to lower it a bit more so it will equal a 4, 6 drop (no air bags).
I'm leaning towards a 700r4 or 200r4 trans for a future upgrade also.

The thing that bugs me about the two piece, is it seems built wrong with no sip yoke. And from what I remember reading here this is completely normal. (Probably why center bearing is going out?) So if I keep this setup I'd like some input as to how I can upgrade it to include a slip yoke.

So share your thoughts and Ideas to why one is better than the other.

[69 longhorn]

On a shortbed truck, you should be able to run a 1 pc shaft, without lenght issues(longbed trucks push that 71" rule on the shaft). The 1 pc shaft is generally built with larger diameter tubing, so you do need to check that you have clearance through the crossmember on your lowered truck for your full range of suspension best of luck,crazyAL.

[scrapmetalart]

replace the u joints, carrier bearing & add a slip joint & not have any more problems.

[Andy4639]

I took the drive shaft out when I installed the 700-R4 back in 1990. I had it shortened and new bearings and carrier installed. Last year I had the carrier done again it wore out. I have a long bed so it a most on mine.

[Sport/Truck]

Originally Posted by scrapmetalart

replace the u joints, carrier bearing & add a slip joint & not have any more problems.

How did you do your slip joint? near the center or at the rear end?
Ware did you get your parts? Used?

If I do the two piece I'm going to use the Inland Empire center bearing.

[GASWAGON]

CPP sell the rear shaft new with a slip yoke built in. I think I paid 199.00? get the urethane carrier bearing and put new joints in the front and have the whole thing balanced.

[Andy4639]

For the price of that Carrier bearing I had the drive shaft re built with new bearings and carrier and balanced. The first one lasted almost 20 years so it was a no brainer for me.

[grs]

I dropped my truck 4 inches in the rear. I put a one piece drive shaft in it. I removed the piece that the center bearing bolts to. I have a short bed.

[GASWAGON]

Originally Posted by Andy4639

For the price of that Carrier bearing I had the drive shaft re built with new bearings and carrier and balanced. The first one lasted almost 20 years so it was a no brainer for me.

The price is for the new slip yoke drive shaft. The bearing is extra. You may have "fixed"the problem, but not the cause of the problem. Not using a slip yoke will also add extra load on the pinion bearings in the rear end and the tail shaft bushing and thrust wsashers on your 700r4. At factory height, it's not a problem because it is only momentary that the load is applied during suspension travel. A lowered truck is constantly exerting these forces on the drivetrain. As the suspension travels up the distance is shortend between the trans and differential. Hope this helps J.

[scrapmetalart]

Originally Posted by Sport/Truck

How did you do your slip joint? near the center or at the rear end?
Ware did you get your parts? Used?

If I do the two piece I'm going to use the Inland Empire center bearing.

My driveline shop told me about $200 to install a slip joint. I havent looked into used ones as of yet.

[cdowns]

i'd drive the truck to a driveshaft shop and ask them for thier best advise and a price quote

[69 longhorn]

Originally Posted by cdowns

i'd drive the truck to a driveshaft shop and ask them for thier best advise and a price quote

Ditto.....

[grs]

Hey Red71, and all. Remove the bracket that the carrier bearing bolts to. It bolts to the carrier support. My truck is lowered 4 inches in the rear. See pic.

[BB72CHEVKT]

I have a one pice in a short bed and one in a long bed. No probs with either one.

[scrapmetalart]

anyone know what cars or trucks a slip joint can be taken fom & added to our driveshafts?

[brad_man_72]

I wouldn't recommend a used slip setup, but I'm sure a front shaft for a 4x4 would be agood way to get close to the same small diameter shaft. This is not a project for the do it yourselfer and needs to be properly ballanced.
please don't spend the money on a billet poly carrier bearing! A properly built driveshaft will last a long time with a cheap carrier bearing.

[Sport/Truck]

Are the one piece units modified from a used shaft? Or are you having them made new at the driveline shops?
The one piece shafts require a slip yoke?

[brad_man_72]

I work in a driveline shop so I build new. You can modify a used shaft. Definitely work for a professional and ballance.

unless you are using a transmission with a bolt on yoke (you can use a slip trans yoke on these transmissions) or use bolt on yoke and have a slip and stub installed at trans end of shaft. The trans yoke provides more than enough slip for suspension travel, and you can't have more than 1 slip in a one piece driveline. It will fall out.

[scrapmetalart]

Originally Posted by brad_man_72

I work in a driveline shop so I build new. You can modify a used shaft. Definitely work for a professional and ballance.

unless you are using a transmission with a bolt on yoke (you can use a slip trans yoke on these transmissions) or use bolt on yoke and have a slip and stub installed at trans end of shaft. The trans yoke provides more than enough slip for suspension travel, and you can't have more than 1 slip in a one piece driveline. It will fall out.

I thought the rear shaft was the problem when lowering & that the slip joint needed added to it....

Maybe the rear shaft just needs shortened after substantial lowering?

[brad_man_72]

my last post was only referring to 1 piece driveshafts.

The stock style carrier bearings do allow for some movement fore and aft. If you use a more solid carrier you would have to put a slip in the rear shaft. Carrier bearing refers to 2 piece driveshafts only. Trailing arm trucks usually don't require much slip at all. Which is the only reason can assume gm didn't see the need for a slip in the rear shaft of a 2 piece driveline.

[Sport/Truck]

I went to the local drive-line shop and ended up purchasing another carrier bearing for the time being.
He was telling me that that a one-piece drive shaft would need to a large diameter as the skinny ones tend to whip/flex in the middle.
He also explained that the carrier bearing allow the shaft to move back and forth like the slip joint (like mention above). But one problem is when you lower the truck your putting allot of stress on the center bearing.
So I'm going to try to determine how much too long my shaft is and see if it's alright with the current setup.

I'm watching my neighbors house while he's away and I took a peak at his 72 step side. It all original and has a one-piece. Could this be because it's a manual transmission?
Should I just leave a note thanking him for the drive shaft?