Drive shaft question - Bagged SWB 72

[MattPSU]

Now that my 5.3 and 4L60E are installed, I started to look at measuring for a new drive shaft. My truck is a SWB 72 and it's bagged with cups/plates and Porterbuilt's bolt in notch. It originally had a 2 piece drive shaft and I was going to have a one piece made. However, it seems that it'll hit the upper part of the cross member when lowered. I attached a long 1x1 to the yolk and ran it to the rear end then lowered it and the 1x1 is really close to the upper part of the cross member when laid out. Is anyone else running a similar set up with a one piece drive shaft?

[BR3W CITY]

Other are, but usually with a notch in the crossmember. Are you hitting the cab bottom or the actual trailing arm xmember?

[kotapug]

I have a 6.2 with a 6l80e with a 1 piece drive shaft and mine hits the 4-link and the cab . I will have to modify both

[lolife99]

Porterbuilt sells a perfect tubular trailing arm crossmember to solve your issue.
Definitely go to the 1-piece driveshaft.

[MattPSU]

Originally Posted by BR3W CITY

Other are, but usually with a notch in the crossmember. Are you hitting the cab bottom or the actual trailing arm xmember?

I'm hitting the cross member. Am I OK to trim it a little?

[BR3W CITY]

If I were the one trimming, I would cut as little as possible and try to reinforce it where I could. Its the point-of connection for your suspension components, so you want it strong.

If I was gonna have an agressive engine combo or race it etc, I'd be way more inclined to go with an aftermarket (or just fab) a new xmember.

Just as a thought, you can also get slightly narrower driveshafts built as custom shops if your willing to pay a little. Not sure how much space you're looking to gain.

[kitsbeach]

Originally Posted by lolife99

Definitely go to the 1-piece driveshaft.

Keith you like the one piece driveshafts best.?

I have no opinion on it but it seems to me like the two-piece solves some of the problems when the truck is lowered. And since mine is in good shape and recently rebuilt I could just do a quick shorten when the time comes. Plus I know semi-trucks use two-piece so there shouldn't be a problem with strength.

Like I said I have no opinion or experience with this. Just wondering what your thoughts are....

[lolife99]

I seem to have trouble finding a good oem carrier bearing.
1-piece is just simpler in my mind.

[lolife99]

2-piece drive lines on lowered trucks need to have a slip yoke in the rear shaft.
Most 67-72 2wd trucks do not. Except the factory 4-speed trucks.

[MattPSU]

Thanks for all of the feedback guys. I finally had a chance to really look at things. Seems that I'm hitting the bracket for the center bearing, not the cross member itself. Looks like I can remove it and have plenty of clearance.

Just when I thought I was done drilling/cutting out rivets...

[kitsbeach]

Originally Posted by lolife99

I seem to have trouble finding a good oem carrier bearing.
1-piece is just simpler in my mind.

Originally Posted by lolife99

2-piece drive lines on lowered trucks need to have a slip yoke in the rear shaft.
Most 67-72 2wd trucks do not. Except the factory 4-speed trucks.

Thanks Keith. It is probably simpler and for a short bed we are not talking about a long driveshaft. My '67 shaft has the slip yoke in it. It's a three on the tree truck but had a four-speed put in it at one time. I've just recently changed it back to three on the tree for nostalgia. Planning an LS and 6-speed later down the road.

[lolife99]

Originally Posted by kitsbeach

Thanks Keith. It is probably simpler and for a short bed we are not talking about a long driveshaft. My '67 shaft has the slip yoke in it. It's a three on the tree truck but had a four-speed put in it at one time. I've just recently changed it back to three on the tree for nostalgia. Planning an LS and 6-speed later down the road.

I was referring to a slip yoke on the REAR shaft of a two piece driveline.
The bottom drive shaft has a slip yoke at the carrier bearig.
The driveshaft directly above it does not.
Both are found in 67-72 longbed and short bed trucks.

[Hart_Rod]

Originally Posted by lolife99

Porterbuilt sells a perfect tubular trailing arm crossmember to solve your issue.
Definitely go to the 1-piece driveshaft.

Keith - it depends on the driveshaft diameter also. I had a 3.5" DS because of the HP in my gold truck with a PB TA crossmember, PB 3" drop trailing arms, and 5" dropped springs. The DS was very, very close to the top of the crossmember. If I had it to do over, I would have modified the PT crossmember OR just went with a 2 piece DS so you don't have to worry about it.