Drive Shaft Vibrations Solved Step-by-Step

How much lift and are you wanting to tilt the pinion up or down?

My pinion is .4* down, but plan on shimming it up 3* to shallow out my u-joint angles. I’m not a believer in matching the pinion and flange on a lifted truck. My lift is 3”.

After replacing my DS, all of my vibes are gone, except for the 15-25 startup vibe from u-joint angles >3*.

Not sure where to find 1.5* steel shims, but it maybe earlier in this thread.

 

I am at 2'' lift in rear with RXT leaf pack @option 2. I need the pinion to drop 1.5* to equal the TC flange. Or I could do a 2* shim and that would give me .5* +/- down from TC flange. Have the harbor freight angle finder so not the most accurate but figured it would get me pretty close

 

Does the TC flange and pinion have to be equal?

I’m entirely not of the school of thought, compared to getting the u-joint angles <3*.

Try this app on your smartphone:

http://www.tremec.com/menu/tremec-toolbox-app/

 

sub'd for future issues!

 

Seems to be several different trains of thought on this. I am by no means an expert, just soaking up what has worked and hasn't. I will check out the app

 

I've been wondering the same thing, as mine is a couple degrees up but someone pointed out if I make it parallel with the TC then my angle will be even sharper on that second shaft (rearmost)

 

I cant see any amount up being good, especially how the third member/pinion will move upward under any sort of load. Gotta get the pinion right, then mess with the cb to dial in the first and second shaft. Atleast thats how I see it.

 

Rear pinion is a constant angle from the flange. When you lift the rear, the delta essentially remains the same, unless you have improperly manufactured and installed springs. However, you increase the operating angle of the u-joints. By shimming up, you attempt to maintain the original angle. I’ve had 2 different driveshaft companies tell me the same thing. Of course, all bets are off with a modded truck. Axle wrap on acceleration, shouldn’t be that much of an issue, unless your u-bolts are not at the proper torque.

No amount of correction with overcome worn components, as with my original shaft had excessive play in the slip joint.

I’m going to shim up, to prevent damage again, due to the 3” lift. I honestly can’t see where angling down the pinion on a lifted truck will do anything other than exceed u-joint operating angles. The geometry doesn’t add up.

This is my opinion only, but YMMV.

 

I agree with most of what your saying, especially about improper installation and or worn parts. Axle wrap may not exist all the time under any and all loads, but it does exist and I think will vary per leaf packs and there stiffness, oem, aftermarket etc..... Also just by lifting the rear of the truck/ lowering the rear axle, the pinion will automatically go up unless there were provisions built in the the leaf packs etc..... So would you not want to lower the pinion a little to bring it back into spec.

I guess there are many variables based on different lift options and manufacturers of those products.

 

I don't know what my original angle was, but after installing the 3 leave AAL, mine ended up at -.4*.

Picture the aft shaft on a hinge, when you lower the axle (lift the truck) the pinion should naturally pivot up, but we're not allowing that to happen due to axle shelf/spring design. Thus the need for shims.

 

I agree. It is still strange to me though that you ended up -4* (down). Mine is + 1.5* (up) requiring me to shim the pinion flange down. Having a hard time even finding a 1.5* shim let alone a steel one.

Just getting started on the whole driveline vibes/ solution. Will post results when get some shims and throw them in.

 

-0.4*

Measurements taken with the DS removed.

 

I had a slight vibration at 20-25mph when I did my Add A Leaf. Added an extension to the drive shaft and it went away
Pre runner, rwd though. Not sure how that correlates to your truck.

 

Extension?

 

God knows this thread may never die.

I lifted my truck, coil overs netting nearly 3 inches up front and the OEM SB pack with a ADL, about 1.5 inches up in the rear, I guess two years ago at 85,000 miles and now, today at 115,000 miles, under warranty, Toyota replaced the three U-joints in my drive shaft due to vibration and a squeaking noise.

In the meantime, last summer we pulled our heavy 20 foot Boston Whaler 2,000 miles and the truck was LOADED. The OEM springs collapsed and the truck has been riding on the extended snubbers since. I had noted a small buzz way before the lift but it went away with the lift. But the last three months it got pretty bad.

When I did the lift, I installed the front diff drop (yeah--yeah) and a CB drop. I did not install degree shims because I am of the school of thought that with a non double cardon drive shaft the TC and the rear diff pinion should be parallel more or less. I do have 2 and 3 degree shims in my glove compartment.

Just last week, I had a local company build a new custom rear spring pack with additional lift (nearly 3 inches now over stock) and more overload capacity. Immediately I felt the truck was smoother but of course by now the drive shaft was a goner. So today, I pick the Tacoma up from the dealer, nothing has changed but for the warranty SB for replacement of the U joints, and it is back to being smooth as silk. My worn Cooper tires grind a little and I can feel the tread at slow speeds but I do not think that is the DS but just the aging tires. I am not sure I can feel a shudder as I start rolling or not, it may be the tires.

I think my drive shaft U-joints were simply worn out, years of towing boats and coupled with the collapsed rear leaf finished them off. I am of a mind to carry on as is and not do anything further to the drive shaft arrangement and then get new tires for my new TRD Pro SEMA wheels.

Or shim the pinion up, install a custom DC drive shaft or?

My lifted Rubicon Jeep, custom Tom Woods DC shaft, I pointed the pinion at the transfer case (slightly below). So, this is not my first rodeo with lifted vehicles.

 

I still plan on tilting the pinion up a few degrees, but mine is pointing down .4 now. My goal is to reduce the angle on the u-joint, as I think that wore out my old shaft.

I have a light vibration below 25 mph.

 

I’m just sayin that the torque converter lockup could be people’s issue. It was mine. After balancing driveshafts, replacing carrier bearings, checking angles, the new valve body is awesome. Like a new truck.

 

If tilting up doesn’t solve my issue, I’ll look there next.

 

Looking for some smarter folks here. Installed OME HD dakar leafs 4 weeks ago (should have netted 2.75" lift, i have actually haven't measured since I did not measure prior to installing the lift), and noticed some vibration. Knew it was the drive-line, but didn't pay much attention since it was minor. Now 4 weeks later, and all the old suspension parts out of the bed and extras (150 lbs or so) and vibration at 15 - 25 mph slowling down is pretty bad. Bought a digital angle finder, and following OP I have the following angles:

TC: 0.0
First DS: 4.3
Second DS: 10.8
RD: 5.8

First and second DS are way out of whack and need to work on correcting the problem. The OME CB drop is already installed, and I will shim it. Seeing the result of the shim, I will then work on adjusting the CB.

I am thinking a 4 degree shim may do the trick, but maybe jumping down to a 3 degree shim and messing with CB might be my best solution. Thoughts?

 

Use this app and be very meticulous when taking the readings:

http://www.tremec.com/menu/tremec-toolbox-app/

Did your truck had OEM shims with the original springs?

If so, did you use them and/or are the installed in the correct direction.

10.8 in the aft shaft seems very high, especially if you used the OME drop kit.