Lifted rear w/ All Pro Exp leaf pack - vibration issues...

A couple days ago I had the All Pro Expedition leaf packs installed, which netted me just about 3.5" of rear lift over stock. I'm now getting some pretty crazy vibrations, especially at lower speeds (around 25-35kph).

The truck is currently at a different shop getting the ECGS bushing installed in the front diff, as well as an alignment. They're also going to install a carrier drop for the driveshaft, and suggested I look into pinion shims for the rear diff, along with (possibly) a center pin, whatever that is.

This is all new to me, as from speaking to All Pro earlier (before the install), they didn't mention me needing any of this (carrier drop/shims/center pin) when I specifically asked whether I need anything other than the leaf springs & u-bolts to do the install. Frustrating, as it sounds like to get the shims/center pin installed I'll have to pay for the entire labour of reinstalling the leaf spring packs again, having just paid it two days ago.

So... does anyone run shims with this pack? If so, which shims, specifically? Any other tips/suggestions?

@allpro

 

My money is on your driveshaft angles now being off: https://www.tacomaworld.com/threads/drive-shaft-vibrations-solved-step-by-step.244535/ The shims will compensate for this, but you need to measure to be sure which one you need. I have yet to measure my angles but my vibes are only from 5-15mph so I can live with it until I have time to find a digital angle finder that's cheap enough for me to justify.

I installed the standards and I needed a driveshaft spacer, make sure yours isn't pulled too far out of the transmission or transfer case: https://www.tacomaworld.com/threads...ent-with-rear-lift-no-vibes-cb-damage.292721/ The center pins they recommend accomplish something similar, but they move your whole axle forward X inches to push the driveshaft back in. The problem with this is you may get more rubbing if you move the axle forward in the wheel well. Only you and your tape measure will know if that will be a problem or not. Tacoma driveshaft vibes are a bitch to track down, tons of threads on here about them.

 

Great info, thank you. I'll pass this on to the shop when I pick the truck up tonight and see how we can proceed.

 

Here's another thread I stumbled across that may be of use to you as a last resort.

https://www.tacomaworld.com/threads/going-to-a-one-piece-drive-shaft-tomorrow.134952/

 

Oh yes I'm watching that thread as well, but for me a $30 angle finder & some $10 shims are way more gooder than a $500+ driveshaft. I'm fairly certain getting the angles correct should solve it, but for some people the time involved is not worth the money saved, to each their own.

 

Nice. Looks like a definitive solution. Glad to hear it's at least a possibility.

I agree, but in my case, the big concern is the labour cost of $139/hour. These guys are the best around, and they charge like it. I'd rather not pay them to swap shims several times around.

If they can measure the angles and find the exact shims, I'm good to go that route. If not, I'll run the single-piece driveshaft idea by them and perhaps get that ordered/installed.

 

Daaaamn! That's pricey for labor. Glad I could turn you on to the single drive shaft option.

 

I just took out all pro standards and put in expos, as my truck got heavier. In my opinion, both springs move the axle rearward one inch from stock. (All pro is not clear about this, IMHO, and they should be.) Then the driveshaft spline joint accommodates that by slipping. But then there is less overlap in the joint, so it may become a source of vibes, especially if it was worn to start with. A driveshaft spacer moves the spline joint back to it's original position.

All pro also sells axle relocation plates, about $35, that fit between the springs and the spring perch. They will move the axle forward either 3/4" or 1". (They have two positions.) They don't work if you have a U bolt flip kit in place.

If you need shims, you may need longer center pins. They are basically bolts with a custom head that hold the leaf pack together in the middle. The head of the bolt fits in a hole on the spring perch, to put the spring precisely in position. I have 3 degree shims, but didn't need the longer center pins.

The least labor way to do things is to try the driveshaft spacer. Install should be less than a half hour. Also, the carrier bearing drop probably has to go in. I would guess 1/2 hour. The shims or relocation plates should take a shop an hour or less.

Good luck.

 

Thanks, that's good feedback.

I picked the truck up today after having the carrier bearing drop installed and having alignment done. Still vibrating like mad in the 25-35kph speed range.

Spoke with my shop, spoke with All Pro, spoke with another shop. The consensus is that it's worth trying shims. On Monday I'll be dropping by a different shop to get the pinion angle measured, and will then order Toytec shims w/ longer center pins.

I'm surprised to hear that the springs would result in the axle being moved back. No one's mentioned anything of the sort to me. (Not doubting what you're saying, just voicing surprise.)

In your signature I see you mention that you have a single-piece driveshaft that still vibrates. Is that still the case with the expo springs? Are your vibrations similar to mine (ie. limited speed range)? And are your angles all "correct" with the new driveshaft in place?

 

I probably should edit my sig, which was written out of exasperation. It used to vibe, then I had it rebuilt, and now I think it is ok. It turned out that the shop the prior owner had build the shaft blew it. I still have front diff vibes at about 40, even though I have a ECGS bushing. I also have vibes at about 75-80, which may be related to front diff, but I'm not sure.

But, the upside is that I don't have any take-off shudder/vibes, and no vibes before 40. Then it's vibe free from 43 to 75. With a single piece shaft my angles are completely different than yours, and simpler. The transfer case flange and the diff flange are parallel. (I don't have a double cardan shaft. Just a u joint at each end.)

I was surprised about the rear axle relocation too. I first saw it when I read through the posts on TW from the prior owner. I called All Pro and asked, and they told me that the springs did not push the axle back. Then I went and stared at my truck and a stock tacoma, and I could see that my rear wheel was not centered in the wheel well like the stock truck. Now with the new expos on, it still looks like it isn't centered. Compare the fender to tire gap right at the bottom of the flare. Please tell me if you think your's is pushed back or not.

 

Here's a bit of a comparison I threw together from whatever photos I had laying around. Last photo is current setup. Measuring tape confirms there's definitely a difference in clearance in front of the tire vs back of the same tire, but I'm not quite convinced that it has changed on my truck from stock.

I scaled all photos to have an identical rim size, as that's the only consistent factor that's easy to work with. Still, hard to do a properly "scientific" comparison from photos that weren't meant for this.

Comparing with an actual stock truck would make things much easier.



Based on the view of the rear mudflap, I'd say the last two photos were taken from roughly the same angle relative to the truck. The middle photo is definitely from a different angle, as the mudflap is at a perfect 90-degree to the camera.

In the last two, the visible gap between the mud flap and the edge of the tire looks about the same, so based on that, I'd say the axle hasn't moved. However, @DaVikes, in your photo, your tire is much, much closer to the rear end of your fender than mine is. Perhaps the axle did move in your case? Can this be attributed to short vs long bed? Or 2nd vs 3rd gen? // edit - you're running 34s and I'm on 31s, that's probably the difference I'm seeing

 

Are you still running stock tires? If you are, then all you need to do is find a lonely stock truck and measure it. I've measured trucks at the dealership before on Sunday because they are not open here on Sunday. It's tough to tell from your pictures if it moved or not. But when you look at the last two, compare the gap between the front of the tire and the rear edge of the front end of the flare. It looks bigger on the second picture.

 

No, I'm on 265/70/17 KO2s. One size up.

 

@DaVikes - I was on the phone w/ All Pro earlier today and they did confirm that the springs do move the rear axle back "a little bit." FYI.

 

Well, at least I'm not crazy. It would be nice if they could come up with a concrete number, lol. I emailed them yesterday asking about it, but I haven't heard back. I measured my neighbor's stock '13, and from the center of the hub to the rear edge of the flare in front of the wheel, it's about 18". On mine, it's about 19". I can't measure very precisely, but it looks like 3/4 to 1". My dilemma is that I also have their hidden hitch and it takes up more room than the stock hitch. So I can't fit a 33" under the bed. The spare I have now is about 32 and its rubbing the diff. So I want to move the axle forward, and I'm trying to figure out how much.

 

I had the drivetrain angles measured by a local driveline-specialized shop.

They told me everything from the tranny back is lining up great, the angle at the center u-joint is "good" (didn't get actual numbers, unfortunately), that the rear piece of the driveshaft is sitting at exactly 7*, and the pinion is at dead 0*. They also mentioned that they had a stock 16 Tacoma in a few days earlier and that one had the pinion sitting at 2.3*. Not sure how relevant the stock numbers are...

I got under the truck last night and used an app on the iPhone to measure the angles myself (not perfectly accurate due to the phone's case and button protrusions - have an actual digital inclinometer on the way from Amazon). I found that the middle u-joint has a working angle of about 0.8* (thus the "good" rating from the driveline shop). According to what's explained in this video...

https://www.youtube.com/watch?v=f1m-Fh5kiRU
... this angle should be as close as possible (ideally within 0.5*) to the rear u-joint's working angle, which is the 7* (7* shaft - 0* pinion = 7* working angle) mentioned above.

All of the threads I'm reading online suggest using shims that are no more than 3*, but there is very little information on actual driveline numbers people have when they use such shims. The driveline shop said 3* shims as an absolute minimum, and suggested trying the 4-5* range.

Given the huge 7* difference in working angles, I'm going to get 4* shims installed next week. Accounting for the roughly 2* increase in pinion angle during acceleration, that should get me pretty close.

Another interesting thing to note is that after greasing the u-joints on Monday, the vibration went away under acceleration, but remained when braking or maintaining speed. This, combined with the fact that the pinion angle increases by those ~2* during acceleration suggests that raising the pinion by those 2* (perhaps to the factory spec of 2.3*?) should eliminate the vibration. However, in that scenario there will still be a very big difference in working angles between the middle and rear u-joints, which (according to the video above) is not right. Or is it? Perhaps Tacomas have a large difference in middle vs rear u-joint working angles right from the factory?

 

Had the 4 degree shims installed and vibration disappeared (carrier bearing drop still in place). Driveline angles are much better now: working angles for rear and middle u-joints are now within about a degree of each other.

There's some possible* vibrations around the 70-80kph range that I still intend to keep a closer eye on. * = not entirely convinced it wasn't the road surface.

 

Good to know. I really need to get off my ass one of these weekends it isn't raining and measure my angles. that 70-80 was just the road surface for you.

 

Yup, road surface for sure. Just came back from doing some city and highway driving and tested out various speeds, accel vs decel scenarios, etc. Truck is smoother than it has ever been.

 

Hey man, just did All Pro Standards and Same issue with my 17 DCSB taco OR. Which shops did you use and where did you get it perfectly dialled eventually? Work on the North Shore and live in a burnaby.