Single (and Two) Piece Driveshaft = Vibes....BE GONE!!!

Are you guys 'overfilling' the rear differential?

 

Sorry dude, not criticizing, just trying to find humor in the situation....trust me, been thru all that with my '05.... Eventually gave up....i went to a tom woods single piece and that helped eliminate the shudder off the line, but at 55mph it hummed like crazy...granted this was all 10 years ago, but i i have little faith there is a solution. prior to that I even got toyota to warranty it, new motor mounts and driveshaft.... Nothing seems to work.......

 

Fair enough. This is a sensitive subject for me today. lol.

I was going to go with the Tom Woods driveshaft, but I was worried about the critical speed issue and long term durability.

 

Obviously.

 

I've got some vibrations after a 2" lift in the rear and I'm strongly considering this single driveshaft option from Tom Woods. I've spoken with both Troy and Josh there and I've since taken the necessary measurements ( and more) to provide to Tom Woods. With this, I have a few questions for everyone:

- Does the Tom Woods driveshaft start at 3.5" dia. and is this the recommended/typical size that people are ordering with stock FD gears?
- The Tom Woods website indicates a two joint for lifts up to 3", and a double cardan for higher lifts. I've only read of people getting the double cardan. I'm taking it that since the double cardan can handle twice the angle of a single joint, the double cardan is the safer way to go regardless of the lift height?
- My additional measurements were to analyze whether the driveshaft would hit the cross member should I hit the bump stop. Under full compression, with a 3.5" DS, I'm a little less than 1/2" away. Since the bump stops are not solid, that little spacing makes me concerned and will likely hit. Of course some, if not all, have cut their cross members. My questions are: Since the success rate of eliminating vibrations with the TW driveshaft is about 90% (per Troy), what if vibrations were not eliminated? Would you then need to weld the cut piece back? Has anyone considered removing the cross member to keep it unharmed?

I see that the cross member is riveted in and probably more of a PIA than cutting, but being able to re-bolt it back has some value. Additionally, I see that the cross member isn't just for the carrier bearing, but also to support the lines that run along side of the truck. I would think fabricating a mount to support these lines wouldn't be too difficult.

FYI, I came up with the exact same measurements for A, B, C1, and C2 that ItalynStylion posted for his truck. Mines is also a Double Cab Short Bed (2014). @ItalynStylion thank you for this thread and your help.

 

@Musubi3 is there any reason why you wouldn't want to go with a custom two piece drive shaft? It really is the best total solution and doesn't require you to cut the cross member. Just take your old drive shaft to a drive shaft shop and tell them you want a double cardan joint welded in behind the carrier bearing. Great time to put a new carrier bearing on too since they'll have it apart. New u-joints are too cheap to say no to and with that, you should be good.

 

You know, I was just thinking that this morning. I could avoid all this hassle with installing a double cardan there. I was planning to re-read the thread to find out how you did yours again. I agree, it would be the best of both worlds. Does the double cardan joint lengthen the rear shaft and, if so, was it accounted for?
Originally, did you cut your cross member then add it back in for your current setup?

 

As I mentioned in my PM, I did NOT cut the cross member.
And yes, the double cardan adds a bit of length when compared to a single u-joint. However, when the drive shaft shop cuts off the u-joint flange they simply cut a little bit more out of the shaft to compensate for the length change.

 

Thanks for the info. Sorry, I was getting confused since you did run the single TW shaft for a bit and the cross member, in general, needs to be cut. I take it that you ran the TW with the cross member intact, but didn't compress the rear much?

 

That's exactly right. When I had the TW shaft (briefly for about 1 month) I did not do any offroading; just highway.

 

One more question for you. You mentioned in an earlier post that your start off vibrations were eliminated with your current setup, however you were experiencing some vibrations at 50 mph. Were you able to address this?

 

The vibrations at 50 were caused by the single piece drive shaft spinning beyond it's critical speed. There are no vibrations present with the two piece double cardan shaft.

 

So how many people have gotten the two piece drive shaft with a double cardan joint right behind the stock carrier bearing and are happy??

 

Why did toyota go with a two piece drive shaft rather than one piece? What's the advantage? Just curious.

 

Better ground clearance with two piece.

 

I went with the Tom Woods single piece recently and I’m happy with the results. Not planning to regear, so I should be good, staying below the critical speed.

Thanks to OP @ItalynStylion for posting the info.

 

88mph?

 

You saw my math in the SC thread. I don't like how low the mph is to reach critical speed. I'm not sold on the one-piece.