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

Lower gearing can make a difference. Tom woods was clear about that when I called in to make the order last week.

 

Don't worry about my shaft getting in contact with other members, it's under control.

 

that was your outside voice...

 

Tom Woods states the # for a 4" shaft is 3500+ ...only thing I can tell ya' is that again... I've never had a single vibe with mine. I take that back...I did have a vibe one time when I might have gotten' a wee bit enthusiastic with the skinny pedal in some rough stuff and I broke the heim on my third member so the axle rolled full tilt and the rear u-joint self clearanced itself in a not so precise fashion :/

 

https://www.youtube.com/watch?v=gmV4qwLfOMY

Get you get an angle finder, check your flanges for parallelism, and get to wrenchin'!

 

WOW! Thanks for posting that vid. I NEVER knew shafts at angles did that.... and the phasing thing was news to me to.

Good vid!

 

Just an fyi. Got off the phone with Josh at Tom Wood's and he said that if you are running stock gears and stock tires, then a 3.5" diameter shaft is all that is necessary. If you are going to go with larger tires and regear, then the 4" is the way to go. I'm on 33s now and might be regearing in the future, so I'm placing my order on Monday for the 4". At $100 extra, I'm just going to do it now. Who has a single piece driveshaft and runs shims to bring the rear end more in line with the transfer case? If so, what degree? Also has anyone changed to single driveshaft on an access cab?

 

Looking to do this in the future for my access cab as well.

 

Well, very much looking forward to your review. Perhaps 4" is the magic bullet for driveline vibes....

 

Update?

 

Will the measurements in post work for all DCSB 2nd gens when placing an order with tom woods?

 

They know exactly what you need, just tell em' what truck you have.

 

Okay cause I called them and some guy named josh answered he was kind of a dick.

 

Should someone go with the 4inch if manual because the gears are 4.10 vs 3.73 of the auto?

 

I told my wife the same thing.

 

They should as long as you are 4x4. Please PLEASE do not overlook that as a very important point. If you don't have a transfer case you need a VERY different length shaft and I believe Tom Woods said they will not produce one at that length.

I would say go for the 4" shaft instead. @Evenflow seems to have had good luck with it but I can't comment on it. Just plan on cutting out your carrier bearing support in the future.

I need to do a full update when I'm not on a business trip (and have had more time in the truck) but for now here's what I'll say.
As we suspected, he had to use a smaller diameter spline stub. That being said, he told me that Toyota has been using that diameter for decades prior to the newer vehicles and that the shaft would break well before that stub would sheer. I told him about @1MK 's experience and he said the only time hes ever seen that happen is when the retaining nut wasn't torqued all the way down. Other than that, he's used that diameter stub in drag cars and it's not been an issue. So I agreed to give it a go. Hopefully that wasn't a mistake!

Opinions beyond this point....proceed with caution
The shaft he made completely eliminates the start off vibrations which is exactly what I was hoping for. However, with no carrier bearing spacers it exhibits a little vibration at 50mph. It goes away at 65mph though. This leads me to believe that will go away when using some carrier bearing spacers like there SHOULD be on the truck to zero the angles. Here's why. I think the carrier bearing height (or other angle zeroing practices) really solve in-motion driving vibrations. But I'm realizing the START OFF vibrations are more a function of axle wrap which is the CHANGE in the pinion angle due to the torque applied to the rear diff which is trying to twist the axle out from under the leaf springs (I have video of this posted below). So although people keep saying, "Zero your angles and you'll be good you fool!" those people are wrong. Because although the angles may be zeroed whilst stationary, the pinion angle changes dramatically when you accelerate hard that that's why you get the start off vibrations (more than likely). This is where the double cardan joint comes into play. It's able to cope with the change in the pinion angle quite a bit better than a single U-joint; exactly twice as good if you want to get technical. This is why the single piece drive shaft solves that issue too.

So once I get home from this business trip (Saturday) I'll be trying out some small spacers with the new shaft. I'll let y'all know how it goes.

Axle wrap video as promised in the above text.

 

I just put the cb back to factory. Vibes are almost gone...not much change from a 3/4 in. drop.

That is a much appreciated video OP. Going to read up on what you did...

 

I'll give them a call today to verify if they will or won't make on for 2wd, if not any other ideas. I'm wanting to just replace the whole driveshaft if possible. Any other companies to look for? I'm really not wanting to go with oem b/c the dealership quoted me 928 bucks which is not in the budget. I'm looking to keep it under 600-700.