Toyota TRD OEM lift kit

My 2021 DCSB TRD O/R MT came with the TRD Lift kit installed prior to delivery at the end of July. This is my 3rd Tacoma (previously owned a 2000, then a 2005). I want to like the truck, and I have been contemplating upgrading my tires to 265/70/R17 with 17-inch wheels to match, but...

The truck now has just over 2,400 miles on it, and it has had a significant "rumble strip" vibration on deceleration from about 30 to 10 mph from day one. It feels and sounds like the left front fender lining is going to rattle right off the vehicle every time I come to a stop. I have had it inspected by Toyota a couple of times, and they tell me they either a.) cannot feel it, or b.) that vibration is "perfectly normal and not a warranty item for a lifted truck."

After my concerns were dismissed by Toyota, both locally and at the corporate level, I opted to remove the rear propeller shafts and center bearing temporarily and operate the truck in 4WD per a TSB from prior years. In that configuration, the truck drove vibration-free, just like I would expect it to in its regular configuration. As soon as the propeller shafts and center bearing were re-installed, using proper alignment & torque values per the FSM, the vibration returned.

I am not sure what to do at this point.

 

Needle bearing

 

or a tapered rear block or a tapered shim to the current rear blocks

 

Interesting. So you have isolated to the rear. Have you tested it while coasting to a stop in gear, stopping with the brakes in neutral or by braking with just the e-brake? If you check these separately you might be able to confirm/deny if the brakes are part of the issue. I'm no expert on this but it sounds like most guys then try the carrier bearing drop or axle shims. Some guys even go to the 1 piece drive shaft to eliminate the whole two piece setup. Seems extreme to me for something that should be Toyota's problem.

 

Thank you. I've read about that, but I don't think my truck's symptoms track well enough to go down that path just yet.

Thanks, this may well be my next step.

I think it is isolated to the rear, yes. I have tested while coasting to a stop, both in gear and in neutral, and by braking with just the e-brake. There is no vibration in the brake pedal or the steering column. Based on testing, I think I have eliminated the brakes as a primary or contributing factor.

I just finished taking measurements of the propeller shaft angle (P/A) and the pinion flange angle (F/A) to determine the joint angle (J/A) as described in TSBs for vibrations involving prior year vehicles.

My digital angle gauge is accurate to +/- 0.05; not sure it is worth spending money to get one accurate to +/- 0.01.

P/A = 8.15 degrees
F/A = 4.35 degrees
J/A = 3.80 degrees (calculated as P/A - F/A = J/A)

I lowered the carrier bearing by 8mm this evening and tested again - no noticeable improvement. I didn’t think to measure P/A again while the carrier bearing was dropped, but I calculated the angle change to be about 0.40 degrees (would result in J/A = 3.4).

I am now trying to find out what the acceptable J/A range is for a 21 TRD O/R with the TRD Lift. No luck with that so far, but on non-lifted trucks, the range seems to be either 1.38 - 3.38 or 1.41 - 3.41 depending on the truck's suspension (standard or firm).

With the J/A at 3.8, it seems like a 1.0 degree shim would be a good starting point (reduce to ~2.8). I have a 1.0 degree shim set on order now. If 1.0 doesn't work, I may step up to 1.5, and then 2.0 to see what happens.

I may also affix a GoPro camera to the chassis so I can see what is happening underneath when the truck is slowing down.

It is absurd to me that I am putting this much effort into solving an issue with a brand new truck, but Toyota has flatly refused to acknowledge that there is an issue. The Toyota corporate rep told me they watch these forums for input. I hope they really are paying attention because I have about 47,000 reasons to keep this issue front and center until it is resolved.

 

@ccarlson

It is really unfortunately that the dealership will not address the issue for you.

The problem may be that the dealership doesn't have any mechanics competent enough to resolve the issue which you have pretty much determined/diagnosed with your testing.

I did not install the TRD lift kit but rather installed the Bilstein 6112 F and 5160 B (similar lift height) with a 1" rear block that included a 1 degree taper. My truck seems very smooth and without any vibration issues. I also have experience with two other Tacoma trucks (2000 and 2006) with over 425,000 miles of use combined.

Hope you get it resolved.

 

@Fast1

Thank you very much for the insight. We have very similar Tacoma experience!

I read about lifts like yours, and they are my motivation for starting with a 1.0 degree shim.

I probably ought to refrain from speculating on mechanic competence, but I do think that is a contributing factor in this case. And this is why I mentioned the issue I am having in this thread rather than a dedicated vibration thread. This issue is involves the TRD Lift, and I hope my experience informs others who are considering the lift.

 

Try putting 200lbs or so of weight in the bed and see if the vibration is still there

 

I did the ECGS bushing and CB drop and still have slight rhythmic vibes between 30-50 mph. Keeping my eye on this to see what you do that solves it for good. I did the 2” in front and 1.5” in back with an AAL vs the block.

 

Tweeted your post out to \@Toyota. Hopefully somebody there takes note. Maybe others here can as well? Here's the permalink to the post.

 

Also following this thread and very curious what you find out. Great info and your approach is methodical. If you ultimately can't resolve the issue, don't want to hassle with lemon law, you could probably sell your truck for what you have into it right now. If you haven't done so, look up the KBB private party value of yours. You'll be shocked. People are actually paying the crazy prices. I just sold my 2018 for a new 2022.

Another thought is, I wonder if anyone ever fabricates some "test" shims to just loosen the u-bolts, install and do a quick test drive to see how it feels before installing the permanent shims.

 

Thank you. I think this is a good idea. If my thinking on this is correct, the added weight (aft portion of the bed for maximum effect) will result in a decrease in the J/A and thus may prevent it from reaching the "critical angle" during deceleration. I can also vary the amount of weight used to see what sort of results different angles yield. This may actually be easier than trial and error with shims.

Good idea - thank you! I am clearly not the only person experiencing this sort of issue, and it is beyond comprehension that Toyota chooses to dismiss it. Sure, they may save the cost of investigation now, but they may lose more in the long run if owners become disenchanted with their brand.

Toyota has been good to me over the years, and their willingness to stand behind their products is why I bought my third Tacoma; however, this current situation is unacceptable to me. I am not content to drive a shaky truck for years in what will amount to an extended QA exercise while Toyota gathers data from myself and others. I live in the here and now, not in the aggregate of their data.

Thanks. I am trying to be as methodical as is reasonable. I am an engineer, and I do part-time maintenance work on a couple of aircraft (mine and a friend's). I may or may not also suffer from a breathtaking case of OCD. Okay, no OCD; however, standards, methodology, and repeatability occupy a large portion of my thinking. Vibrations beyond a certain amplitude are destructive, and while I don't think my truck is necessarily at risk right now, I know the long term result will be excessively worn u-joints and damaged differential bearings. That outcome is not awesome, especially since I am aware of the issue and can do something to avoid damage now rather than have to repair it later.

I think I would refrain from the lemon law approach. That is far too much time and effort for me. If I can't get this resolved fairly quick, I will just sell the truck, get something different, and suggest that friends and family steer clear of Toyota for the foreseeable future.

I will keep all of you updated as I progress in this nonsensical exercise.

 

I really think the suggestion to add weight would provide a quick test on minimizing vibration. Similar to removing some of the installed lift improving the diff/drive shaft angle, ie more like stock.

I'd go a bit more in weight (250/300 lbs)or at least measure the drop from the rear fender after adding weight to obtain at least a minimum of 3/4" drop.

I experimented with different weights in the box over the rear axle before I purchased my topper to gain a better understanding of the ride height I'd obtain before purchase. I have an AC V6 so that may differ a bit due to box length and overall weight of the vehicle vs a 4 door.

 

Update...

As noted earlier, I decided to try the use of weight in the bed to see what effect loading might have on the vibrations. It definitely made a difference.

I used items I had readily available to provide weight - some landscape blocks, bags of fertilizer, and a 5 gal bucket of sand. Ultimately, I decided to do two tests: one using ~200 lbs, the other using ~350 lbs.

Weight was added in the far aft portion of bed, distributed as evenly as I could get it across the tailgate. All of the weight was behind the rear axle.

I measured "drop" as the distance from the ground to the bottom edge of the fender flare using a 48" ruler with a built-in bubble level. I don't know what value it has in any of this, but it was measurable... so I measured.

As I was testing, I noted that maximum vibration appears to occur at about 14 mph in all configurations, which leads me to think r.p.m. is almost certainly a factor (propeller shaft balance??).

I wish I had a better way describe the vibration (inches per second of acceleration would be ideal), but I don't own or have access to the equipment necessary to take such measurements. Consequently, I will have to rely on "calibrated adjectives."

0 lbs:
Drop: 0.00"
P/A: 8.15 degrees
F/A: 4.35 degrees
J/A: 3.80 degrees
Regular braking: moderate vibration
E-braking: moderate vibration
Coasting: slightly less vibration than when braking

~200 lbs:
Drop: ~0.625"
P/A: 7.70 degrees
F/A: 4.80 degrees
J/A: 2.90 degrees
Regular braking: substantially reduced vibration
E-braking: substantially reduced vibration
Coasting: vibration present but barely noticeable

~350 lbs:
Drop: ~1.0625"
P/A: 7.45 degrees
F/A: 5.15 degrees
J/A: 2.30 degrees
Regular braking: vibration present but barely noticeable
E-braking: vibration present but barely noticeable
Coasting: no vibration detected

My conclusions from the weight-in-the-bed exercise:

If the truck had the level of vibration present with ~200 lbs in the bed, I don't know if I would have paid much attention to it.

If the truck had the level of vibration present with ~350 lbs in the bed, I don't think I would have noticed it at all.

Vibrations appear to be linked to rotation speed of the propeller shaft, and therefore I suspect they are likely to be the result of a slight imbalance in the shaft. I think this because maximum vibration is always at about 14 mph, regardless of bed loading (J/A) or the method of deceleration (except while coasting at 350 lbs where there were no vibes detected).

The fact that the vibration amplitude appears to decrease as J/A decreases leads me to think my truck's vibrations are a direct result of the lift (duh?), which is (obviously) common with lifted vehicles.

The fact that Toyota refuses to recognize and correct the matter is infuriating, but I am not going to hope and wait months or years for them to do the right thing, even if this is their warrantied (but not warrantied??) lift kit.

Based on the above testing, I think I am going refrain from installing the 1-degree shims, as originally planned, and install 1-degree tapered 1-inch blocks instead. I think tapered blocks will have a slight J/A advantage over the shims because shims would further increase the rear lift by about 1/8 inch.

I hope all of this is helpful to others considering the TRD Lift kit.

 

@ccarlson

If you proceed with a tapered block, I'd scrutinize the TRD offroad kit blocks currently installed and the placement to validate they were installed correctly. I know there are some factory install directions floating around that you might want to get your hands on for assessing the currently installed blocks and to assist with the replacement 1 degree taper blocks. (just found them and sent them to you via PM)

 

Yes sir… you make excellent points. Looking at the diagrams in the documents you sent (thanks!), it seems the spacers with the TRD lift may be much less than an inch thick. So much for my 1-inch tapered block plan.

I don’t think the TRD lift blocks have any taper built in, but I will find out for sure when I have a detailed look at them this weekend. Wouldn’t it be something if they did and were installed backwards… doubtful, but I’ve heard of far worse.

Regardless of my final solution, I am at least glad to know the vibration can be all but eliminated with some tweaking. I just wish Toyota would step up and take care of it. They address vibes in the 2021 DCSB TRD O/R w/ an automatic transmission, so why not solve on the trucks with manual transmissions? So damned lame.

 

Being that u own a trd offroad model, there are already shims installed between the spring and axle. U would just need to figure out what angle of shim u would need to replace them with.

 

I’ve looked at the vehicle, the parts diagrams, and the TRD Lift install instructions. I don’t see shims on the truck, in the diagrams, or mentioned at all in the lift kit instructions. Would you be able to point me to a source for the stock shim information?

 

TRD Off-Road Suspension Lift (Install Instructions)

 

Just to make sure we’re talking about the same things… I see the spacer blocks in the suspension lift instructions (and on the truck), but I don’t see shims anywhere in the instructions, parts diagrams, or on the truck.