Slight vib upon acceleration at 70mph.

[scwill]

Ive read other posts already, just looking for additional places to look. Best way to describe what im experiencing is this: cruising up to speed everything is great, once im at highway speeds 65-70 and i accelerate i have a small vib at my feet. If i punch it you cant feel it (almost as if i accelerate through it), but if i accelerate pretty good you can feel it. If i let off the pedal it goes away, its only under acceleration or under a load, but once im at speed and cruising its not there. U joints are good. Im thinking its a transmitted vibration from the transmission under load. What would yall be looking at? Transmission mount? Would cv axles cause this? Maybe its normal?

 

[gatormark91]

Motor mounts look good? Can you feel the vibration in the shifter at all?

 

[scwill]

Motor

Motor mounts look good? Can you feel the vibration in the shifter at all?

Motor mounts good. Nothing felt in shifter.

 

[slacker24-7]

Stock height ? Or has it been raised recently ?

 

[scwill]

Stock height ? Or has it been raised recently ?

Stock. Raised tbars, but vib there before i raised them.

 

[scwill]

Motor mounts look good? Can you feel the vibration in the shifter at all?

You can feel vibration coming through the HI LO shifter when driving, but this is normal I believe. They main shifter has zero vibs. Had my brother drive the truck yesterday and he thinks Im crazy. He said, "yeah there might be a tiny vib, but its a truck dude". Im chalking it up to me being overly anal. I dropped skid plate yesterday and put grease in shafts and u joints, looked around at all the bushings and mounts everything is super clean and normal. If I truly am getting some type of vibration, Its going to be extremly hard to track down.

 

[scwill]

Question for you all: Should I try to remove drive shafts one at a time and see if that helps. Remove rear and drive, then remove front a drive?

 

[scwill]

Would bad u joints in the shafts contribute to my original concern? Also would bad cv's contribute to my concerns? I know the PO re booted them and they are the original shafts, I just dont know why they would vib at high speeds, then stop when i let of the gas. Any insight is appreciated. Thanks

 

[4Beast]

You're not crazy. At least not for this I have the same thing, as do a lot of other people. Honestly, if this is my only worry, I'd say I am quite lucky, but it is a tiny bit of a bother. I think it is the driveshaft, so if lubing the U-joints and shaft don't do it, then maybe try your shaft removal trial. For me it's always at high torque just before it goes down to the next gear, 2500 RPM, i think.

 

[scwill]

You're not crazy. At least not for this I have the same thing, as do a lot of other people. Honestly, if this is my only worry, I'd say I am quite lucky, but it is a tiny bit of a bother. I think it is the driveshaft, so if lubing the U-joints and shaft don't do it, then maybe try your shaft removal trial. For me it's always at high torque just before it goes down to the next gear, 2500 RPM, i think.

Exactly man, your last sentence is spot on. Im going to try removing drive shafts and driving this week, maybe it will tell me something, most likely, with my luck, it wont. Would my CV's have any contributing factor?

 

[gatormark91]

Rotate the tires, too. You might have a slight inbalance.

 

[scwill]

I just tried to take a swing at the rear drive shaft, jesus those bolts are not moving. Zero rust, they are just on there super tight. I have 14mm socket with extension and 14mm box wrenches, nada. I guess i will re group and try again tomorrow, maybe with a cheater bar. Question though, im pretty sure all my joints have never been changed, 140k on the truck. Whats the normal life span on these joints? Thank ya.

 

[Spike555]

I get a slight vibration at speed too, empty pop cans drive me nuts in the cup holder and anything metal touching the transfer case shifter.
I just move these items and keep on trucking.
It's a truck, unless the rear view mirror is vibrating so bad I can't see out of it...I'm not worried.

 

[scwill]

I get a slight vibration at speed too, empty pop cans drive me nuts in the cup holder and anything metal touching the transfer case shifter.
I just move these items and keep on trucking.
It's a truck, unless the rear view mirror is vibrating so bad I can't see out of it...I'm not worried.

So youre saying do

I get a slight vibration at speed too, empty pop cans drive me nuts in the cup holder and anything metal touching the transfer case shifter.
I just move these items and keep on trucking.
It's a truck, unless the rear view mirror is vibrating so bad I can't see out of it...I'm not worried.

Spike, So what kind of life would a person expect to see out of the ujoints? 150k, 200k, 250k?? Its a hard one to answer I know. Thats why I figured what the hell I will just remove the shafts and check the joints. Have you ever removed your shafts, any tricks?, Long Cheater bar? I weigh 250 and put all my weight into it and they didnt move. Sprayed with lots a pb blaster and will try again.

 

[scwill]

Pulled front drive shaft yesterday. The bolts had lock tight on them and were very tough to break loose. Marked the shaft with paint before i pulled it. Locked center diff and went for a spin. Absolutely no change. I dont think pulling rear will lead to anything but im gonna do it anyways. Will report back.

 

[LostAfrican]

Search for my thread "SOLVED: Drone @2400 - 2800 rpm ...". In my case my rock sliders were contacting the body at the front foot wells. Tried a bunch of stuff before I found this. Do you have sliders or bumpers that might be an issue? Did you remove the flux capacitor frame weight thinger?

 

[DirtDawg]

It could also be other things such as motor/transmission mounts, front diff bushings, etc.

 

[scwill]

Ive read your thread. No rock sliders here. Ive seen pictures of the weight thing, I dont know exactly where it is supposed to be but I have not seen it on my truck, nothing on the frame rails. I doubt that is my issue. Thanks LostAfrican.

Dirt Dawg. Transmission and motor mounts look good, havent checked diff bushings. I guess the only thing you can do there is just start replacing bushings and mounts. Chasing down a vibration blows big time!

 

[DirtDawg]

Dirt Dawg. Transmission and motor mounts look good, havent checked diff bushings. I guess the only thing you can do there is just start replacing bushings and mounts. Chasing down a vibration blows big time!

I agree, its hard to pinpoint sometimes. Once you rule out the spinning masses, you then look to rubber or other vibration transmitters to diagnose your issue. The engine mounts on our rigs arent notorious for going out, but also not uncommon. Most who have replaced their motor mounts can't fully see the failure until they are removed. You also gotta look at the aging characteristics of rubber. Based off of external conditions and time, rubber hardens and cracks over the years. I replaced my transmission mount a while back and even though it appeared fine, there was an apparent difference in the pliability of the two rubber mounts.

 

[scwill]

I agree, its hard to pinpoint sometimes. Once you rule out the spinning masses, you then look to rubber or other vibration transmitters to diagnose your issue. The engine mounts on our rigs arent notorious for going out, but also not uncommon. Most who have replaced their motor mounts can't fully see the failure until they are removed. You also gotta look at the aging characteristics of rubber. Based off of external conditions and time, rubber hardens and cracks over the years. I replaced my transmission mount a while back and even though it appeared fine, there was an apparent difference in the pliability of the two rubber mounts.[/QU
I hear ya. I think im going to pull rear drive shaft first then look at replacing transmission mount, motor mounts, front diff bushings. Since they all look good what would you replace first?