SOLVED - Front right vibration under load - Comment my thinking (1 Viewer)

[GerLC100]

Ok, so this is another thread about front drive axle noises, but I couldn't find any other thread with those specific symptoms. Trying to put together everything I learned and think and look forward to comments.
Basic idea: reduce too much extra work and money by trying to apply logical thinking :-D

Basic Situation of what I did:
Cranking stock TBs to 22"
Dobinson C56-167 with 2" lift (rear 1.5" higher than front)
new Dobinson UCAs
Dobinson IMS extended travel front, MRR rear
Slee Diff Drop
new wheels/ tires all around (SCS F5, MT Baja Boss 285/75-16)
balancing of wheels/tires
wheel alignment
stock CV axle, not changed
all bushings (OEM rubber) and ball joints (555) LCA new

Symptoms:
- front right vibrates increasingly during acceleration noticeably at ~50mph
- vibration increases with higher speed to a fair amount of wobbling at 70mph (didn't want to go higher)
- left turn increases vibration/ rumble
- right turn decreases vibration/ wobble
- going up or downhill doesn't make a difference
- flat highway and cruise control reduces vibration/ wobble so you would think you're driving MT tires
- no vibration at all when no load on CV axle, going straight, left or right turn
- Steering wheel doesn't shake significantly
- low pressure on brakes doesn't affect anything
- right pull: nothing without load, a little bit keeping speed, more under load
Edit/ add on: I don‘t hear any typical metallic grinding noises or clunks coming for example from a wheel bearing

possible causes and my thoughts, from low probability to high probability:
- Wheel balancing --> low as there's no vibration/ wobble without load, smooth as a new car; also wouldn't explain the strong left/ right turn dependency
- Wheel bearing --> low as there's no vibration/ wobble without load, smooth as a new car
- Diff "internals" --> low as I didn't touch anything there and I guess it would also affect the left side and not show the left/ right turn dependency
- any bolts loose/ Diff bushings --> low as I have checked all bolts again after I felt the vibration and there's no movement/ nothing loose
- Wheel alignment --> medium as the front right caster is just hitting the spec
- not enough grease anywhere --> medium as it would explain a noise but not that heavy wobbling after driving 50 miles total after install
- drivetrain overall --> high as I feel a difference load/ no load
- axle flange --> high as this is often described in other threads
- CV axle bad --> high as it's just old

My action plan is:
- Today: check play in CV
- Tomorrow: Change axle flange and C Clip (arriving tomorrow) and regrease wheel bearing for the sake of completeness as it's open already
- if that doesn't help get a new CV from Napa (2nd gen with improved design: NCV 944081)


Would you confirm my thinking above?

 

[GerLC100]

Couldn’t wait ^^

Took the wheel off and also the flange. There is something, whereas the main point is: is it cause or result?

The CV outer teeth are slightly damaged whereas the rest looks pretty well for 270k miles.

The teeth of the flange also look good to me, with some wear. Either way: new ones arrive tomorrow.

BUT:
I guess my mistake was to reuse the snap ring… it was sitting fairly loose, lost tension and wasn’t flat anymore!
And seeing that it already worked it’s way into the flange surely shows some “in and out” movement… you can clearly see the print of the snap ring.

The CV axle itself has a very slight play up and down on the inner side. Slight play of the middle part in and out, but I think it’s normal.
Also found the inner side boot to loose oil.
Perhaps I have just tilted it too much during my swap and it got broke a bit earlier than during normal use…

Two questions left:
1. Do you think this is the root cause of evil and swapping CV, flange and snap ring solve it?
2. Would you go for cruisertec’s OEM or Napa’s new ones? I’m ok to pay OEM as long as there is a technical advantage.

 

[2000UZJ]

I'd start by lowering the front end down to 20.5"-21". I set my '06 to 22.5", and went down to 22" and had some crazy vibrations. I finally set mine at 20.5" and it's smooth as room temp butter . Lowering back down to 20.5"-21" is free, easy, and should help reduce angles. Keep in mind, these trucks are boats, and the preload on t-bars is insane. So when you floor it, that front end will stand up, making those CV's run pretty much maxed out! Lower control arms need to be as flat a possible!

 

[Trunk Monkey]

There's no technical advantage to OEM, but there's a HUGE longevity advantage. Plenty of reports on here of NAPA style CV's either vibrating new out of the box or wearing out prematurely, esp. on a lifted truck.

 

[Bisho]

Also check for play in your tie rods and steering rack. while you have it in the air.

 

[GerLC100]

Ok, so OEM it would be.
But nobody blames the outer CV teeth yet, which might already be a good sign

Steering rack, inner & outer rods got replaced 20k miles ago by previous owner. I also replaced outer with 555 during the suspension work and just checked: no play at all.

Also just turned the TB’s 4 full turns back and will see tomorrow morning if there is any chance/ shift to other speeds/…

 

[GerLC100]

I'd start by lowering the front end down to 20.5"-21". I set my '06 to 22.5", and went down to 22" and had some crazy vibrations. I finally set mine at 20.5" and it's smooth as room temp butter . Lowering back down to 20.5"-21" is free, easy, and should help reduce angles. Keep in mind, these trucks are boats, and the preload on t-bars is insane. So when you floor it, that front end will stand up, making those CV's run pretty much maxed out! Lower control arms need to be as flat a possible!

Interestingly everything gets more intense when I “unload” the bar on the right side during a left turn. The TB is being bend in the less loaded direction as the LCA would in theory be push up by the leaning vehicle

 

[100d ua]

I'd start by lowering the front end down to 20.5"-21". I set my '06 to 22.5", and went down to 22" and had some crazy vibrations. I finally set mine at 20.5" and it's smooth as room temp butter . Lowering back down to 20.5"-21" is free, easy, and should help reduce angles. Keep in mind, these trucks are boats, and the preload on t-bars is insane. So when you floor it, that front end will stand up, making those CV's run pretty much maxed out! Lower control arms need to be as flat a possible!

Oh look, another front end vibration post.

What's the point? I mean, if you go with a 2" lift, which is by far the most common on the 100 series and do a 20-21" lift at the front, you've got some serious rake. Not to beat a dead horse, but as soon as most people lift their 100's they start to experience the never ending saga of trying to figure out what's causing their vibration. CV axles, U-Joints, tires, drive shaft? WHO KNOWS?

But i'll put away my tin foil hat now, it's not that much of a common problem

 

[oakback]

There's no technical advantage to OEM, but there's a HUGE longevity advantage. Plenty of reports on here of NAPA style CV's either vibrating new out of the box or wearing out prematurely, esp. on a lifted truck.

I'm the type of guy that always tries the cheap option first, because for many things I don't use it so hard and it's good enough for my uses.

The CV axle was one instance where it did not go my way. About a year of regular on-road use had me replacing the CV axle with OEM. No major off-roading during that time, and it's not lifted, but it didn't take long for vibrations to kick in, and only got worse over time.

 

[GerLC100]

Update: found grease on the inner side towards the diff.
So good that I just ordered 2 OEM CV’s from Cruiserteq with ETA Thursday/ Friday

Will start from there and see how it goes. MUST be possible just driving 65mph and not 110mph on the highway

 

[GerLC100]

Just swapped the CV and flange yesterday and did a test drive. Not a big change, so root cause still present.

Edit: also made sure to have the right C Clip out of the set I ordered

What I found:
Front right caster is just at the lower end of spec, 1.8.

Could that possibly be the root cause? Increase to 2.5 or something?!?
Would Caster make sense seeing the front right bets worse in a left turn/ under pressure?

 

[2000UZJ]

Just swapped the CV and flange yesterday and did a test drive. Not a big change, so root cause still present.

Edit: also made sure to have the right C Clip out of the set I ordered

What I found:
Front right caster is just at the lower end of spec, 1.8.

Could that possibly be the root cause? Increase to 2.5 or something?!?
Would Caster make sense seeing the front right bets worse in a left turn/ under pressure?

Castor typically helps with return to center with steering, and tracking in a straight line. If one side is higher than the other turn in could vary under certain conditions.

This won’t affect CV vibration of driveline unless it’s so far out of whack. I’m running 2.5* castor and a front hub to fender if 21”. Drives butter smooth. 22” yields insane vibrations under heavy throttle. Hence why I am a bit lower than most.

 

[GerLC100]

Thanks 2000UZJ.

I’m somewhat still not sold on the fact the lift is the root cause. I went down to 21.5” and no difference.
In addition the following scenario doesn’t really explain it:
Stand a red traffic lift and make a 90* left turn on a highway under mid-strong acceleration —> I get that vibration/ shatter/…

If I’d only have problem 50-70mph on the highway… yeah ok. But why in a sharper left turn 0-15…
An unbalanced tire also doesn’t explain it at these low speeds…

 

[GerLC100]

Just spent 1h under the front and got some questions.

first off: I couldn‘t find anything that‘s obviously loose. Pushing/ shaking the right wheel towards the engine/ inside under regular load I have a slight feeling it moves the UCA more than on the left side. So could be a pointer, but could also be that I‘m just looking for something

I found that the front drive shaft has play at the slip yoke, u joints feel fine. So will regrease all 3 and see.
Question 1: when I want to test the front without load is it enough to remove the drive shaft? I can keep the flanges on right? Do I need to turn on the central lock?

I found that the steering rack moves slightly when going full turn left to right, right to left. 2-3mm?! Bushing are not totally destroyed, but have surely seen better times. Don‘t think this explains my issue at a u turn under medium/ high load.

The inner part of the (new) CV axle can be moved slightly up and down in the diff. As the old CV on the left moves as well and even a bit more I also assume it‘s normal.

So right now I got the drive shaft… :-(

 

[GerLC100]

Just thought I provide an update.

I still got this issue and now decided to drop it off at my favorite shop next week. As much as I want to do it myself I also need to make sure the car runs when we want to go on holiday in 3-4 weeks... This shot has to work!

I ordered all parts to fully refresh both knuckels incl new DBA rotors and pads.
My current assumption is the needle bearing or the bushing...

While they're on it they can take a look at my other ideas:
- front diff: I have a fair rotational play in my front driveshaft; ujoints are tight
- it could possibly also be linked to something loose. Like diff bushings or so. When going over bumps it sounds like a bad sway bar bushing although I disconnected the sway bar already. I checked the whole front suspension under no load (lifting the frame) and under full load (lifting the UCA) and couldn't find anything that's loose...
- Steering rack had been replaced by the previous owner not too long ago (50k or so), but the bushings don't looks super new. Not super bad as well, but whatever... The rack moves by ~3-5mm in the bushings from full left turn to full right turn.

I also rechecked with Mike @ Exit Offroad and I'm right on spot of Dobinsons hub to fender target of 21.75" (range would be 21.5-22).

Will keep you posted, hoping my refresh takes possible play out and solves it.

 

[GerLC100]

Next update: via a different thread here (clunk P to R...) I checked my diff mounts. When shifting the bushings move and I also ordered those for replacement.
At that point the front end is close to 100% new :-D

But the bad bushings could perhaps also cause the noise when in a left turn the diff moves and starts rattling... Let's see...

Will update next week if all that solved my issues

 

[lewdog998]

Next update: via a different thread here (clunk P to R...) I checked my diff mounts. When shifting the bushings move and I also ordered those for replacement.
At that point the front end is close to 100% new :-D

But the bad bushings could perhaps also cause the noise when in a left turn the diff moves and starts rattling... Let's see...

Will update next week if all that solved my issues

 

[lewdog998]

Any updates on this...I am having similar issue.

 

[GerLC100]

I'm replacing the diff bushings this weekend and the knuckle refresh is scheduled for 3/26.
So if all goes well I can provide a positive feedback Sunday

 

[GerLC100]

Just did the front bushings (333, 334, 331) yesterday. Shifting clunks gone, but driving still present.

Will be checking some more stuff today (engine mounts,…) and keep fingers crossed my knuckle refresh solves my issues.