Driveline Problems 5 years later

I have an 06 DC 4x4 that I purchased new. I never noticed any vibration issues with the stock supension. About two years ago I installed OME 885 coils, add-a-leaf and front and rear OME shocks (plus new UCA's). I do not have the rear TSB done to this truck. For around 2 years I drove the truck and did not notice any types of vibes that really caught my attention. Its a lifted truck so the rides definitely stiffer then stock, but nothing bothered me while driving.

I should note that I've used my truck for a lot of landscaping projects for my home over the last couple years. I've hauled probably 10-15 loads of mulch and 3 loads of sand and it usually would compress the rear all the way down to the bump stops. I recently noticed that my left rear OME shock is blown. The bottom half of the shock is coverd in black soot and the rear alex below the shock looks to have a oil stain. I believe the shocks are oil filled so I'm assuming a seal has busted and the shock it pretty much dead.

Anyways, not sure if the blown shock is related, but over the last month a driveline vibe has developed. I feel it in the floor board during take and while driving. It is more noticable on take off. I took it to a mechanic and he thought it was the CB worn out. I've read through most of the drive line threads on here and started to diagnose the issue.

I measured the driveline angles starting by zeroing on the T-case flange. I then measured the 1st D/S, 2nd D/S and rear pinion flange. I had the following measurements: T-case flange = 0, 1st D/S 6.1, 2nd D/S 5.8, rear pinion flange = 3.9up. I used a Wixey digital degree finder and double checked with a second digital degree finder and was able to duplicate my measurements. Based on my research, I plan to adjust using axel shims to get the rear pinion flange closer to zero or maybe even 1 degree down to account for axel wrap.

I also measured the amount of lift I currently have and the rear sits about 1 inch higher then the front.

Also, I've already ordered 3 new spicer u-joints for the D/S and a new CB that I will be installing over the xmas break. I wanted to fix the D/S angle before I installed the new u-joints and CB.

My questions are:

1. If I want to adjust the rear pinon down 5 degrees do I simply install 5 degrees shims (fat end foward)?

2. Is it normal to have the rear pinion pointing up with an add-a-leaf? I thought most lifts were causing the rear pinion to point down.

Thanks in advance for your help.

 

I would look into replacing the carrier bearing if it is worn before messing with shims and angles since you had no issues with the lift before. There have been several instances where the CB appeared to be fine but when the driveshaft was rotating, it would wobble in the CB. I would think the best way to determine would be to temporarily mount a go pro or something similar down there and go for a drive.

 

if it has been ok for awhile with the lift, then started after many miles of driving...


check center support bearing, might be ready for renewal, also, check universals....


when you have a lift, you don't want the pinion going down, actually, you would want to shim it up a bit and possibly drop the center support bearing a smidgen to help with the angles....


do a search here, many threads on driveshaft angles, pinion angles, bearing drops and axle wrap, somewhere among all these suggestions has to be your answer...

 

Thanks for the suggestions..

Yea, I've read from beginning to end two of the biggest D/S vibration threads on this forum and the general consenses is that the t-case flange and rear pinion flange need to be as close to equal, but at opposite angles to cancel each other out. Then the 1st and 2nd D/S need to also be as close to equal as possible by adjusting the C/B.

I agree that it is probably the CB or u-joints which is why I stated I've aready ordered them and plan to replace all u-joints and the CB at the same time. However, I think the reason I didn't have vibrations to begin with is because the CB and U-joints were just strong enough to counter act the vibration that was there and just masked the problem.

I don't want to install new D/S parts and it fix the problem and say well that was what was the problem. I want to make sure the D/S angles are correct this time around.

 

Does the vibes go away when you put it into 4W HI? If so its your front diff bearing...

 

I haven't tested it in 4WD, but ill give it try at lunch today. It really feels like the vibes are coming from the rear though. They feel like there directly under my seat and under the center console area.

 

Crawl under your truck and see how much play your carrier bearing has

 

I thought the same thing on mine but I tried the 4w HI thing and GONE! Give it a try at least it will norrow things down for you. Just make sure to not do any tight turns in 4wd on dry pavement.

 

I had a mechanic take a look and I have been under the truck a bunch of times checking on it. The mechanic thought it had excessive play. I would need to compare it to a new CB to see how much is excessive, so I'll just have to take his word. By design the CB is supposed to be able to flex so its just hard for me to know how much is too much. I can move it about 1/4 of an inch up and down.

I can't find any play in any of the 3 u-joints, but I know that this test isn't always perfect and they can still be going bad.

I do all the maintenance on my vehicles my self and will be dropping the D/S to replace the CB and u-joints my self as well.

 

How much vibration should be coming of the T-case while in park? With the truck running and in park I can put my hand on the 1st drive shaft right next to the T-case and there is a ton of vibration there.

 

Since you feel the vibration underneath you, I would start with the cb vs changing out the front bushing in the diff

 

I drove the truck in 4HI up to about 30-35 MPH today and I still had the same vibes. Hopefully, replacing the u-joints and CB will fix the problem.

 

I'm subbing to find out the issue too...

What's the latest on this?

 

I'm actually glad you brought this thread back up because I'm still trying to figure out what is wrong with my truck.

So to update the thread. I replaced all 3 u-joints in rear D/S and center bearing with Spicer parts and I still have the exact same vibrations. All the needle bearings in the u-joints looked very good so I don't think they needed changing.

My vibes are still very bad and I think are continuing to get worse. During my drive home from work (20 Min Commute) if I have my left foot on the foot panel and other foot on the gas my legs will be tingling and feel like they have fallen asleep the vibaration is so bad. My rear view mirror also lucks kinda fuzzy while driving and if I grab it everything looks clear and then if you let it go its back fuzzy again.

I've read the front diff bearing thread all the way through and I really think that could be the issue bc if I switch into 4HI around 35 MPH it seems to get a little better and then when I switch out of 4HI I can notice a distinctive moan come back. I'm hesitant bc everyone with the front diff problem seem to say it goes completely away when in 4HI and mine definitely doesn't go completely away.

Also, and this may be unrelated... my vibes get a lot worse if I just barely apply the gas. So if I'm driving down the road doing 35 and going up a hill and I just put the weight of my foot on the gas peddle the rpms will go up about 1000RPM the truck will vibe harder and then all the sudden RPM's will drom back down 500RPM and its like the truck is just boggin out. If I apply more gas the engine just pulls through and accelrates fairly normal. And what I'm describing is not the normal way the A/T works when it switches to a higher gear and drops RPM. The trans is not switching gears when this happens.

I may have a couple different issues going on right now. I've got 100,700 miles on the truck and its never had the trans fluid changed. I picked up 14 qts from the dealership yesterday and I'm going to drop the pan and do the DIY flush this weekend and change out the entire fluid and I'll be able to see how much metal shavings I have in the pan.

I'm tempted to change out the front diff bearing to the ECGS bearing, but I'm on a budget and I really want to make sure the next parts I buy for the truck fix the issue.

 

motor mount?

 

Yea, that has crossed my mind as well. I'm guessing you need an engine lift to change the mounts out? I do all the work on my truck, but I don't own a lift so I would have to pay somebody to do this for me. I wonder how much shops are charging for this...

Also, I noticed back when I installed my UCA's (around 50K miles)..so its been a couple years... that the ball joints were marked because my front lift was so tight. This was when I had the top spacer along with the 885 and everything was really tight. I removed the spacer when I installed the UCA's, but I reused the original ball joints to try and save money. I wish I would have went ahead and replaced them... I wonder if bad ball joints could cause any of this?

 

A few more questions for you...

How many miles on the new U-joints?

Did you grease them after replacing?

I don't know if they come pre-greased or anything, but my father-in-law kept asking me what this "shuttering" sound was when I would first start accelerating. I didn't notice it, so I couldn't answer. My wife said she felt some vibration when driving it after lifting. I don't notice it, so i started doing a little research on here. I took mine up to the shop to do an alignment (second one in two weeks, but that's another story) and asked how much they would charge to grease the u-joints. They didn't charge me for it, and my father-in-law said that he hasn't noticed that noise since.

How do your tires look? Any feathering in the front? How many miles do you have on them?

When was the last time they were rotated? There's no adjusting the alignment in the rear since the tires are on a solid rear axle. Depending on how long those have been back there, they should be round and not feathered. Does the situation improve when you rotate?

When was the last time they were balanced?

When was the last time you had an alignment done?

What kind of UCA did you install? Maybe replace the ball joint?

Has the transmission fluid ever been changed? <-- I don't see how that would cause vibes, but since you mentioned it.

What about the front and rear differentials? transfer case? those three are very easy to change, and use the same gear oil.

I've read some things about the tranny supports and/or where it mounts to the engine. I think there's a TSB on it, but don't quote me on that one.

How does your carrier bearing look? Did you install a cb drop kit?

What's the angle of your drive shaft? Did you install shims with your lift?

Could the drive shaft be bent?

Do the vibrations get worse at certain speeds, or is it constant?

 

My vibes are really noticable anything above 25-mph. I'm starting to think it is the front diff bearing (huge thread on this) bc if I'm driving 30-35mph and switch to 4HI the vibes kinda go away and then when I swith back to 2HI I hear a distinctive moan start back that sounds simliar to mud terrains going down the road. I will be replacing the front diff bearing with ECGS bearing when I get a few free hours.

 

Dayum!

You've visited quite a few avenues toward getting this thing figured out.

I'll be interested to know how the new front diff bearing and TSB for the tranny work out. Personally, I would start with the TSB.

I felt like I was reaching on some of those, and still feel like I am, but have you checked the front wheel bearings?

In my wife's previous car, we had a slight rumbling noise when the steering wheel would turn to the right. Even if it was just ever so slightly. Alignment numbers came in good every time. After replacing the tires, I noticed some uneven wear and had the wheel bearing replaced. I've heard of people having to get that done to these trucks fairly often.

Does the vibration get better/worse when making turns (even just veering left or right on the highway)?

Maybe get a single drive shaft?

 

The wheel bearings have crossed my mind. Your right, I've seen a lot of threads about people having failures. I wish somebody could tell me without a doubt if my wheel bearing is bad before I go spending anymore money and time on another fix that doesn't solve the current vibe. I think they can put one of those magnetic measuring devices that can measure just how much play there is in the wheel bearing to see if it is acceptable. May have to start looking into this. Good luck with your truck. I'll report back after I install the front bushing.