LWB to SWB Drive line Swap - Concern with slip yoke vs non-slip

[88Stanger]

Currently i have a LWB that was converted to SWB. Original Turbo 400 rebuilt and installed. I currently have a 2 piece drive shaft with i think a non-slip yoke and would like to go to a 1 piece drive shaft but i am concerned about the yoke and what all i need to do to make this work. I am looking at this because i have vibration that i cannot get rid of yet. I am told that flipping the carrier barring over will help, not sure if this is true. Had the drive line cut 1. maybe it is too long? looking for help please.

Thanks

[hewittca]

I have a shortbed conversion as well with a two piece shaft. I shortened the second half shaft by 12" and it fit right in, but I too had a vibration. After doing some measuring, I figured I needed to raise the carrier bearing up a bit to get the angles better. Then I noticed the stock crossmember has two sets of holes punched in it for the carrier bearing bracket. Mine was in the lower set of holes. After I moved it to the upper set of holes, my vibration was gone. As far as I can figure, the lower set of holes are for longbeds and the upper set are for shortbeds.

[chevykevy]

Huh, I'm in the process of a long to short conversion as well and have a couple two piece drive lines that I have been looking at to have cut. I have been gathering parts for the bearing that mounts with the two bolts in line with the drive line and the type of bearing that mounts perpendicular to the shaft. Which are you guys using?

[hewittca]

The 67-72 trucks used the mount with the bolts in line with the shaft, so that's what I stuck with. The 73-up trucks used the other style, which is a definite improvement over the 67-72 style mount. Here's my mount. I actually lowered my truck quite a bit after doing my conversion, so I did the bearing flip mod to get rid of a slight vibration due to lowering. In the top of the crossmember you can see the two sets of holes for where the mount was originally attached.

[chevykevy]

Ok, did lowering create a more straight or direct in line route or create more angle ?

[chevykevy]

I mean lowering shaft not truck

[hewittca]

Believe it or not, flipping the bearing actually raised it up compared to the stock location. It straightened out the driveshaft by doing this. I think before flipping it the angle between the front and rear shaft was 7 or 8 degrees and after flipping it I could put it wherever I wanted. I set it to 2 degrees.

[chevykevy]

Thanks, good info, I think I'll bring truck to drive line guy when the time comes and we can decide the best position, upper or lower, thanks!

[71meangreenc10]

Originally Posted by hewittca

The 67-72 trucks used the mount with the bolts in line with the shaft, so that's what I stuck with. The 73-up trucks used the other style, which is a definite improvement over the 67-72 style mount. Here's my mount. I actually lowered my truck quite a bit after doing my conversion, so I did the bearing flip mod to get rid of a slight vibration due to lowering. In the top of the crossmember you can see the two sets of holes for where the mount was originally attached.

Try looking at a 67-72 with leaf springs. Different set up.

Smitty

[Rufas]

Why not ditch the two piece driveshaft with all the compound angles and just have a single driveshaft made? Not that expensive and really simplifies things. Any driveshaft fab shop can build one for you.

In fact I have a long bed that I have removed the two piece driveshaft and replaced with a one piece driveshaft.

[chevykevy]

Thanks, good info, I think I'll bring truck to drive line guy when the time comes and we can decide the best position, upper or lower, thanks!