Folks that went to a two piece DS - How is it now you've had it a while?

I was having driveline vibration issues since I bought my '91 Xtracab. Had a local driveline shop balance it a couple times. First time it was out of phase so they "properly" phased it (despite them cutting and welding the rear/double cardan section 90 degrees out from stock). Replaced the center support bearing a few times. Finally I had Tom Woods custom build me a new rear half of the rear DS from the double cardan back. When I bolted that up and took it to the driveline shop to balance it, they told me they discovered the spline on the front half where the flange slips on was actually bent and they had to straighten it out. Why they didn't notice it the previous half dozen times it was in there is beyond me. Short story long, my bad vibrations are mostly gone, with the exception of some lighter rhythmic vibes when coasting down from around 60mph to 45mph.

In the image below, you can see my stock rear section and the custom section made by Tom Woods. You will also notice how the double cardan has been cut, clocked 90 degrees, and rewelded. I don't know why the driveline shop did this but they told me it wouldn't be a problem.

Looking back to my convo with Shawn Wood, he was initially recommending I just do the one piece and be done with it. When calculating the critical speed of a one piece driveshaft of the length I'd need though, the DS speed would be almost 3k at 60mph and 3,460 at 70mph which is pushing it. Plus I didn't love the idea of crossing the point of no return by having to cut out the center support bearing for clearance.

TLDR - Folks that ditched their stock two piece driveshaft for a one piece driveshaft, any thoughts or regrets on how it worked out compared to your stock two piece?

 

I had a 1 piece built for my X-cab Long Bed. It's longer than the d-line in my Suburban. Still a little bit of wiring before I can drive it though. We went though all the specs and came up with a shaft with a S



picer HD slip yoke with chevy half ton u-joints with toyota conversion flanges. Shaft is 63.5'' long with .083 wall tubing 3.5'' in diameter

 

I was tired of changing carrier bearing all the time and went to a 1 piece Its long, and it hits some stuff, but overall no regrets. The strength and simplicity was worth it.

Mine is trail only, so its made from 2.5 schedule 40, which is .20 wall.





Schedule 40 vs stock thickness

 

Yikes, that’s a skinny rope of a DS! Surprised you went with 2.5” instead of 3.5” or 4”. How long have you been running that? I know the main issue with a driveshaft the length I need is critical speed, and Tom Woods uses 3.5” minimum if not 4” diameter for longer shafts to bring that number up.

 

I was surprised also, but he said it is a wheelin' rig so it may not see any highway driving. My shaft was spec'd at 3.5''. I wanted a lighter d-line with 065 tubing, but they said nope 083 minumum

 

Yes, trail only. No pavement. The only time this truck sees highway is when its on the trailer. You would probably want a shop to make this so it could be balanced. I was just replying that a 1 piece shaft will work.

Its the same size as a stock shaft, see the comparison pic above . Looks like I made it in 2018. It may be "thin" but has over double the wall thickness of others mentioned here. Im also only about $40 into it, as all I had to buy was the pipe. We re use the stock Toyota ends because they are the strongest.

I have slammed if off many rocks, and you can lift the truck up by it if you need to. Shes solid for sure.

Heres the post in my build thread: https://www.yotatech.com/forums/f199/rattlewagons-1992-pickup-build-up-thread-224943/index32.html#post52412754