Driveline vibration Tsb out

This is all about getting the correct matching angles. Disclaimer: The following is all speculation (IMO): The newer trans mount that came out in 2008 seems to have gotten the transmission/transfer case flange to come out around 3 degrees, which is a world standard for drivetrain angles. It seems like the problem with the original (pre-2008) mount is that it created too steep of a working angle between the trans and the first half of the driveshaft which also seemed to cause a decel vibration around 18 mph. prior to 2008. The newer style mount since 2008 seems to have dropped the transmission/transfer case down about 1/4" from where it was originally to lessen the u joint working angle. The original mount would have had the transmission/transfer flange angle at around 1.5 degrees, which would be around matching the current pinion angles that we are seeing. The pinion angle now needs to be adjusted to match the newer trans angle. I accurately (within 0.1 degree) measured all of my angles with a digital angle finder with the following results:
1.) Trans flange angle= -2.8
2.) 1st driveshaft angle= -6.6 degrees
3.) 2nd driveshaft angle= -5.8 degrees
4.) Pinion Angle= -4.5 degrees

With these numbers, I get a working angle at the trans u joint of -3.8 degrees, 1.2 degree working angle at the center u joint, and +1.4 degrees at the pinion u joint. A 2 degree tilt downward of the pinion in my case would get the pinion angle around -2.5, which would closely match the trans flange angle and match the working angles (-3.8 at the trans and +3.3 at the pinion). When the pinion is rotated down, the second driveshaft angle will steepen, and should decrease the 1.1 degree center angle more towards 0 deg. The joint would need a slight angle for it to wear correctly.

The answer to this seems to be the following: Whatever configuration these trucks are in (lifted, stock, tsb springs, etc.) the trans angles and pinion angles need to be as close as possible, and the center angle needs to be close (not perfectly) to 0.

 

Revolving vibration from 25-40MPH. I have about 15,000 miles on my 2013 and have a revolving vibration that the dealership can't figure out. They've replaced a front wheel bearing, no fix. The shop foreman tried to tell me that the problem was fixed, yet I felt it right back when I was driving it home. Brought it back a week later (in the shop now) and so far this is whats happened. Shims under the center bearing of the driveshaft and he said it helped a little bit but didn't fix it. Removed the driveshaft, drove it in 4WD high and said the vibration was completely gone. Drove it with another vehicles driveshaft and vibration came back. O-scoped the rear diff and checked the fluid for metal and signs of wear and tear, nothing wrong. Checked the transfer case for sign of wear and tear and fluid for metal, nothing wrong either. Basically they can't find the problem. I've read a number of other guys having the exact same issue, seems to be common for Tacoma guys. Unfortunately I put my Revteck 3" lift on it at about 2K miles so knowing rather the lift created the issue or not is hard to tell. Dealer wants me to return the suspension back to stock to attempt the new TSB. Since I feel the issue very obviously in the floor boards Im thinking that the Center Bearing on the driveshaft could be flexed too much. And the shims helped it a little but gives me a little hope to just increase the amount of shim to about a 1/2" total. I've heard about CV joints wearing fast, possible wheel bearings being bad. Who knows. Any experience out there with this issue?

 

Very true but at what cost. I already tinkered with the rear suspension to attempt at stopping the rear vibe and helping the truck handle any load what so ever. I have come to the conclusion that I have to live with it. Not that its a huge issue, I have had worse vibes on my Jeep. Remember everyone is a tough guy online.

 

NO. But I expect the truck to not have the issues in the first place. I had a highly modified TJ Rubicon and dealer fixed TSB that could of been caused from the vehicle modification, and it was but they fixed it. Some manufactures are just more "mod" friendly apparently. Not trying to be a smart ass but Toyota has dropped the ball, the 2nd Gen has been around for quite a few years and they cant get this fixed? WTF.

 

The problem with having the center u joint at a 0* is the fact that the transmission u joint and pinion u joint are 90* out of phase... which will cause driveline vibrations in itself.

As stated in the spicer PDF (page 17) you would have to rotate the center u joint 90* to make the 1st and 3rd u joints in phase.



Preferably though

You either make the u joint out of the transmission as close to 0 as possible (right at 1* is best to keep the joint lubed), then make the plane of the pinion shaft and first half of the drive shaft parallel (2nd and 3rd u joints at the same angle but opposing)

Or the opposite of that... the pinion angle (3rd u joint) close to 0* and make the plane of the transmission output shaft and 2nd half of the u joints parallel (1st and 2nd u joints same degree but opposing angles)

Preferably you do the first to not have a driveshaft hanging down.

Like this.



Now, what it seems like toyota is doing is getting the first u joint angle closer to that 1* mark vs the current steeper angle by lowering the rear transmission mount then playing with the rear pinion angle to get the first shaft and pinion shaft parallel.

 

On another note but still on topic I called Tom Woods Driveshafts and as of right now the way they have been correcting 90% of vibes on Tacomas is with a double-cardon single piece DS. But this will hurt those of us that run our trucks off pavement with a DS that hangs lower and is more apt to damage from obstacles.

 

NAAAAAAAA
You not being a smart ass.
Your frustrated like everyone else.
I still think they went the wrong way when they got rid of the double cardigan joint.
I think they should have built a shaft and tried it in the current suspension parameters.

Seems a shaft would have been a way to evaluate that possibility.
I'm going to check my angles but I doubt if I will do anything.

 

I wont sell the truck for the vibe its not that bad just annoying. what do you think about a single piece DS? Seems to have worked for many.

 

I would honestly much rather see a 2 piece with double cardian like on the 1st gen tacos... those had no driveline vibes.

 

The individuals who cant get the TSB are left with attempting to fix the issue on there own, IF THE ISSUE IS FIXED BY THE TSB OF COURSE. The DS replacement may be my option but going to see what other more experienced members with lifted Tacos do. Sucks balls but another waiting game until we actually have proof on what works

 

what will work is rear springs that dont have tons of axle wrap. and thats why alot of people who go with heavier duty springs report reduced or eliminated driveline vibes as the springs resist axle wrap much more so than the stock springs.

The one of the reasons why a single shaft works is 1, you can get it with a double cardian which allows for a wider range of angles, 2. you will likely set the angles up to be more proper when installing the single piece unit, and 3, with the standard spring axle wrap because its one piece over a longer distance, the angles of the u joints change less.

This ENTIRE situation is cause by axle wrap... you have 4 runners and FJ's with zero driveline vibes... why... a 4 linked rear suspension with 0 axle wrap. which is perpetuated by a very soft center carrier bearing, and out of spec u joint angles.

 

^^^^^^^ I agree !!!

 

I read that. many owners on here are going to resort to there own fix for obvious reasons. shame Toyota couldnt get it right. oh well looks like gotta spend more money lol. you have the professional experience and know how to measure correctly and not second guess yourself but many others on here dont. many will just live with the vibes or attempt at trying to fix it some with good results and others not so good results

 

Yea I have been looking around at prices for full leaf packs. I don't want more than 2-2.5" or else I will need to screw with the front again.

 

I want to know how you suggest they plan on helping those out with aftermarket leaf packs when it's the leaf packs themselves that are being replaced to "fix the issue"

 

Let's see how this tsb works out for some members. Very curious. I hear issues are due to axle wrap but some are also due to drive line angles correct?

 

They're not going to help anyone out that has altered the suspension

 

that was my point....

 

but , if a fix is worked out , that can still help the lifted guys as far as a solution to the issue

 

yes it can... and its been stated before and im pretty sure theres a big thread on it, on how to properly measure your driveline angles and adjust accordingly.

Toyota finally got wise and in the newest tsb they are starting to do the same.