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'96 Bronco 5.8L. 2.5" Tuff Country lift w/ extended radius arms, 33" Duratracs. Saginaw swap.
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Discussion Starter · #1 · (Edited)
This is something I’ve been experiencing with my ‘96 Bronco (since I purchased it back in October) that I have been unable to diagnose thus far. I just hit 153k on the odometer. 5.8L Engine.

The primary issue I’m facing is a mainly front-end shutter that starts at 65 miles per hour and seems to get slightly more severe the faster I go. From what I can tell, it is not associated with braking, transmission, or engine rpms.

This issue was occurring when I first purchased the truck and has continued to occur in the same fashion after new tires, 2.5” lift kit, and other repairs as noted below:

-Front end alignment
-Front/rear driveshaft balance, all new u-joints, slip yokes cleaned and re-greased
-Rear differential serviced/ pinion seal
-Wheel bearings/ hubs cleaned re-greased
-Ball joints
-Tires
-Tire rotation and tire balance (x2)
-Steering gear/pitman arm
-All shocks
-Radius arms
-Front brake job (rotors resurfaced, rebuilt calipers, pads, abs wire)

Any advice or ideas of any sort would be appreciated.

Thank y'all very much for your time.
 

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If it is not a Bronco, it's just not worth driving.....
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1,900 Posts
How big are your tires? Larger tire amplify all shudders and vibrations.

Have you replaced your axle pivot bushings? They can wallow out and provide a loose joint for your axles.

I don't see a front end alignment in your maintenance list. If you have too much toe in your front end can shudder given the right conditions.
 

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281 Posts
A bronco with a lift and a vibration at speed would have me looking at pinion to drive line angle. With a double cardon joint at rear of transfer case their should be 1 to 2 degrees of difference between the drive line angle and the pinion angle.
You can get an angle finder app for your phone.

In my case a 4" lift (2 inches at the rear axle) caused a very slight vibration at 55 mph and up.
After measuring the DL angles on mine, the drive line was 17 degrees and the pinion was at 12 degrees. I need to add 2 degree shims and that puts me at 14 pinion and 16 drive line angles.

Tom Wood's
How To Measure Drive Shaft Angles

 

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'96 Bronco 5.8L. 2.5" Tuff Country lift w/ extended radius arms, 33" Duratracs. Saginaw swap.
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35 Posts
Discussion Starter · #4 ·
How big are your tires? Larger tire amplify all shudders and vibrations.

Have you replaced your axle pivot bushings? They can wallow out and provide a loose joint for your axles.

I don't see a front end alignment in your maintenance list. If you have too much toe in your front end can shudder given the right conditions.
I did make sure to get an alignment after the lift kit. 33x12.5R15 tires. Thanks for the axle pivot bushing idea
 

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1996 Bronco XLT, 5.8, Auto Everything.
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435 Posts
I'm sure this isn't the issue, but just because it bit me once...

Does it happen on multiple freeways? I once spent a long time trying to find a high-speed shaking/noise in a car... turns out the only patch of my commute where I could get on the gas was just very badly paved.
 

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'96 Bronco 5.8L. 2.5" Tuff Country lift w/ extended radius arms, 33" Duratracs. Saginaw swap.
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35 Posts
Discussion Starter · #6 ·
I'm sure this isn't the issue, but just because it bit me once...

Does it happen on multiple freeways? I once spent a long time trying to find a high-speed shaking/noise in a car... turns out the only patch of my commute where I could get on the gas was just very badly paved.
Haha! Believe it or not- I did consider this option. Unfortunately it is everywhere… I’m sure glad that was your only issue, though!
 

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29,132 Posts
This is something I’ve been experiencing with my ‘96 Bronco (since I purchased it back in October) that I have been unable to diagnose thus far. I just hit 153k on the odometer. 5.8L Engine.

The primary issue I’m facing is a mainly front-end shutter that starts at 65 miles per hour and seems to get slightly more severe the faster I go. From what I can tell, it is not associated with braking, transmission, or engine rpms.

This issue was occurring when I first purchased the truck and has continued to occur in the same fashion after new tires, 2.5” lift kit, and other repairs as noted below:

-Front end alignment
-Front/rear driveshaft balance, all new u-joints, slip yokes cleaned and re-greased
-Rear differential serviced/ pinion seal
-Wheel bearings/ hubs cleaned re-greased
-Ball joints
-Tires
-Tire rotation and tire balance (x2)
-Steering gear/pitman arm
-All shocks
-Radius arms
-Front brake job (rotors resurfaced, rebuilt calipers, pads, abs wire)

Any advice or ideas of any sort would be appreciated.

Thank y'all very much for your time.
Yo T
Following from 1996 Bronco/F-Series Workshop Manual partial @ http://www.diesel-dave.com/vehic/manual/stj/stj04003.htm#extract_24
"Vibration Conditions
Vibration, technically, is a high-frequency trembling, shaking or grounding condition, felt or heard, that is constant or variable in level and occurs during a portion of the total operating speed range. The types of vibrations that can be felt in the vehicle can be divided into three groups:
  • vibrations of various unbalanced rotating parts of the vehicle
  • body and frame vibrations excited by powertrain, wind or road inputs
  • tip-in moans or resonance vibrations from stressed engine or exhaust system mounts or driveline flexing modes
For engine or accessory vibration, all speeds, refer to Pinpoint Test D in the Diagnosis and Testing portion of this section.
For high-speed shake/vibration, 80 km/h (50 mph) and up:
  • Refer to Pinpoint Test A in the Diagnosis and Testing portion of this section and to Section 04-04 for tire conditions contributing to shake/vibration.
  • Refer to hub and rotor runout checks in Section 06-00.
For tip-in moan, refer to Symptom Charts in the Diagnosis and Testing portion of this section. If the symptom still exists, refer to Pinpoint Test B in the Diagnosis and Testing portion of this section or the engine assembly in Section 03-01A, Section 03-01B, Section 03-01C or Section 03-01D.

For brake shudder, refer to Section 06-00.
Vehicle vibrations can also be subdivided into those that occur at low speeds and those that are most noticeable at higher speeds. Since the dividing line between low and higher speed vibrations is not clear, there will be vibrations that overlap the two ranges.

Typical Low-Speed Vibrations (Less Than 72 km/h [45 mph])
  • exhaust vibration
  • engine harshness
  • driveline vibration due to improper driveline angles
  • power steering pump disturbances
  • air conditioner compressor or drive belt (8620) vibrations
  • take-off shudder (driveline problems)
  • brake roughness or harshness
  • driveline roughness
  • driveline slip-yoke or rear axle universal joint flange (4851), automatic or manual transmission clutch slippage
Typical High-Speed Vibrations (Above 72 km/h [45 mph])

  • rear axle universal joint flange runout or imbalance
  • driveshaft (4602) imbalance
  • excessive tire-wheel and drum assembly imbalance
  • tire roughness due to high non-uniformity (force variation) or out-of-balance condition
  • rear axle pinion gear pitch line runout
  • excessive tire and wheel runout
  • worn suspension components
  • front end accessory vibrations
  • exhaust vibration (greatly reduced in exhaust systems de-coupled by a flexible coupling and mounted with blade and block hangers)

Harshness Conditions

Harshness is the term commonly used to describe the ride quality concern of the vehicle. A hard ride or harshness is usually caused by the tires or suspension system, namely:

  • overinflated, wrong size or wrong type tire installed on the vehicle
  • suspension not sufficiently lubricated
  • worn suspension components
  • suspension components installed with preload on pivot point, bearings and bushings
  • vehicles equipped with tires not specified by the manufacturer (different brand tires often give different ride qualities to the vehicle)
  • bent or bound-up shock absorbers
  • heavy-duty components installed on vehicle
Other harshness conditions that affect ride quality may be summarized as follows:

  • Vehicle bounce — the vertical motion of a vehicle on its suspension system, front and rear in phase, a low frequency "float" or an intermediate frequency "kick."
  • Vehicle pitch — the out-of-phase vertical motion of the front and rear of the vehicle. A flat ride would be considered the opposite of a pitch ride.
  • Vehicle roll — the side-to-side rotation of the vehicle body about the front and rear axles.
 

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93 XLT 347, GT40 Heads, Bassani headers/exhaust, E4OD
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Man, do I feel your pain... 2-1/2 years, 8 mechanics and $9k detailed here:


This was an exceptional issue. As one old timer told me "90% of vibration problems are tires or wheels. 9.9% are driveshafts and you son have the 0.1% that is unexplainable."

Despite consensus amongst everyone who drove the truck that the vibration was coming through the seat/floorboard and thus the rear end, the problem wound up coming from the front end - driver's side wheel studs/hub were not concentric to the axle.

We found it through a piece of software @miesk5 suggested: Noise Vibration Harshness NVH App Vibrate Software Automotive Diagnosis

Not inexpensive, but if you have eliminated tires/wheels, driveshafts/u-joints and driveshaft angles it may be worth looking into. Wish we weren't on opposite coasts, I'd be happy to go for a ride and run the software for you.


Sent from my iPhone using Tapatalk
 
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'96 Bronco 5.8L. 2.5" Tuff Country lift w/ extended radius arms, 33" Duratracs. Saginaw swap.
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35 Posts
Discussion Starter · #9 ·
Man, do I feel your pain... 2-1/2 years, 8 mechanics and $9k detailed here:


This was an exceptional issue. As one old timer told me "90% of vibration problems are tires or wheels. 9.9% are driveshafts and you son have the 0.1% that is unexplainable."

Despite consensus amongst everyone who drove the truck that the vibration was coming through the seat/floorboard and thus the rear end, the problem wound up coming from the front end - driver's side wheel studs/hub were not concentric to the axle.

We found it through a piece of software @miesk5 suggested: Noise Vibration Harshness NVH App Vibrate Software Automotive Diagnosis

Not inexpensive, but if you have eliminated tires/wheels, driveshafts/u-joints and driveshaft angles it may be worth looking into. Wish we weren't on opposite coasts, I'd be happy to go for a ride and run the software for you.


Sent from my iPhone using Tapatalk
Wow, man! I’m SO happy for you that you finally solved your issue. Must feel great. And it does give me some hope. I’ll take a look into this.
 

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'96 Bronco 5.8L. 2.5" Tuff Country lift w/ extended radius arms, 33" Duratracs. Saginaw swap.
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35 Posts
Discussion Starter · #10 ·
Thought I'd update everyone. It was the tires!! Discount Tire is awesome and replaced all of mine for free. Three out of four were defective as seen by running the truck on jackstands.
 

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93 XLT 347, GT40 Heads, Bassani headers/exhaust, E4OD
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1,767 Posts
Thought I'd update everyone. It was the tires!! Discount Tire is awesome and replaced all of mine for free. Three out of four were defective as seen by running the truck on jackstands.
Glad it got resolved. My experiences with Discount Tire have been positive as well.
 
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95 5.8L MAF XLT, Hedman Shorties/MF SS Y & Muff, E4OD, Man hubs, KYB Quads, 31x10.5x15, 304K miles
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I had the same problem a couple of years ago and it finally got straightened out at Discount Tire. Might I ask what Brand and Model tire was your problem with? You can PM me if you don't want to mention it on the site. Curious Steve
 

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'96 Bronco 5.8L. 2.5" Tuff Country lift w/ extended radius arms, 33" Duratracs. Saginaw swap.
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35 Posts
Discussion Starter · #13 ·
I had the same problem a couple of years ago and it finally got straightened out at Discount Tire. Might I ask what Brand and Model tire was your problem with? You can PM me if you don't want to mention it on the site. Curious Steve
I got Wrangler Duratracs 33x12.5R15
 
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