97 F250 HD vibration

[rusty ol ranger]

97 F250 HD 2wd 460 Auto

Over the past 6 months or so ive noticed a hum/vibration (slight) that seems to be getting worse.

Initially i wrote it off as tire noise because it seemed to change tone on fresh vs older pavement.

But friday after the truck had sat probably 3 or 4 weeks i drove it and it was pretty bad. Its only noticable between 50-60mph with the worst of it being at 55. However it did lessen in severity the further i drove it but it didnt go away.

I also noticed it stops when you are coasting so that kinda kills the tire noise theory.

It seems to be coming from right under the cab or back. My gut reaction is a U joint but i never hear any clunking while changing gears.

It has a carrier bearing/2 piece drive shaft so im wondering if that could be it? But i always understood those got noisy while coasting and not under torque?

Or could it possibly be more serious like a pinion bearing? Ive never had one of those go out. But its not leaking from it.

I havent crawled under it yet cause its cold as shit and i dont drive it much but i need to get it fixed before spring when i use it the most.

Any input?

 

[bilbo]

I had this with my 94 F250 a couple years back. I ended up replacing both U-joints and the center bearing. The bearing wasn't bad but the rubber isolator was pretty much toast. I still notice a drone but it helped a lot. You might have seen this already but I had found a post in another forum about vibration. It might help you narrow things down a bit. I saved it and it's copied below, good luck:

TRR—Tire and Wheel Radial Run out: Vehicle speed sensitive, mechanical vibration. The run out will not cause vibration below 20 mph (32 km/h).

WH—Wheel Hop: Vehicle speed sensitive, mechanical vibration. The wheel hop generates rapid up-down movement in the steering wheel. The vibration is most noticeable in the 20 - 40 mph (32 - 64km/h) range. The wheel hop will not cause vibration below 20 mph (32 km/h). Wheel hop is caused by a tire/wheel that has a radial run out of more than
0.045 of-an-inch (1.14 mm). If wheel run out is acceptable and combined run out cannot be reduced by repositioning
the tire on wheel, replace tire.

TB—Tire/Wheel Balance: Vehicle speed sensitive, mechanical vibration. Static tire/wheel unbalance will not cause vibration below 30 mph (46 km/h). Dynamic tire/wheel unbalance will not cause vibration below 40 mph (64 km/h).

TLR—Tire/Wheel Lateral run out: Vehicle speed sensitive, mechanical vibration. The run out will not cause vibration below 50 - 55 mph (80 - 88 km/h). Excessive lateral run out will also cause front-end shimmy.

TW—Tire Wear: Vehicle speed sensitive, audible vibration. Abnormal tire wear causes small vibration in the 30 - 55 mph (88 km/h) range. This will produce a whine noise at high speed. The whine will change to a growl noise when the speed is reduced.

W—Tire Waddle: Vehicle speed sensitive, mechanical vibration. Irregular tire uniformity can cause side-to-side motion during speeds up to 15 mph (24km/h). If the motion is excessive, identify the defective tire and replace it.

UAJ—Universal Joint (Drive Shaft) Angles: Torque/vehicle speed sensitive, mechanical/audible vibration.
Incorrect drive shaft angles cause mechanical vibration below 20 mph (32 km/h) and in the 70 mph (112 km/h) range. The incorrect angles can also produce an audible vibration in the 20 - 50 mph (32 -80 km/h) range. Caster adjustment could be required to correct the angles.

UJ—Universal Joints: Engine torque/vehicle speed sensitive, mechanical/audible vibration. If the U-joint is worn it will cause vibration with almost any vehicle speed/engine torque condition.

DSY—Drive Shaft and Yokes: Vehicle speed sensitive, mechanical/audible vibration. The condition will not cause vibration below 35 mph (56 km/h). Excessive run out, unbalance or dents and bends in the shaft will cause the vibration. Identify the actual cause and repair/replace as necessary.

WB—Wheel Bearings: Vehicle speed sensitive, mechanical/audible vibration. Loose wheel bearings cause shimmy-like vibration at 35 mph (56 km/h) and above. Worn bearings will also produce a growl noise at low vehicle speed and a whine noise at high vehicle speed. The wheel bearings must be adjusted or replaced, as applicable.

AN—Axle Noise: Engine torque/vehicle speed sensitive, mechanical/audible vibration. The axle will not cause mechanical vibration unless the axle shaft is bent. Worn or damaged axle pinion shaft or differential gears and bearings will cause noise. Replace the defective component(s) as necessary.

SSC—Suspension and Steering Components:
Vehicle speed sensitive, mechanical vibration. Worn suspension/steering components can cause mechanical vibration at speeds above 20 mph (32 km/h). Identify and repair or replace the defective component(s).

EA—Engine Driven Accessories: Engine speed sensitive, mechanical/audible vibration. Vibration can be caused by loose or broken A/C compressor, PS pump, water pump, generator or brackets, etc. Usually more noticeable when the transmission is shifted into the NEUTRAL position and the engine speed (rpm) increased. Inspect the engine driven accessories in the engine compartment. Repair/replace as necessary.

ADB—Accessory Drive Belts: Engine speed sensitive, audible vibration. Worn drive belts can cause a vibration that produces either a droning, fluttering or rumbling noise. Inspect the drive belt(s) and tighten/replace as necessary.

DEM—Damaged Engine or Transmission Support Mounts: Engine speed sensitive, mechanical/audible vibration. If a support mount is worn, noise or vibration will occur. Inspect the support mounts and repair/replace as necessary.

ES—Exhaust System: Engine speed sensitive, mechanical/audible vibration. If loose exhaust components contact the vehicle body they will cause noise and vibration. Inspect the exhaust system for loose, broken and mis-aligned components and repair/replace as necessary.

 

[Poppa_R]

97 F250 HD 2wd 460 Auto

Over the past 6 months or so ive noticed a hum/vibration (slight) that seems to be getting worse.

Initially i wrote it off as tire noise because it seemed to change tone on fresh vs older pavement.

But friday after the truck had sat probably 3 or 4 weeks i drove it and it was pretty bad. Its only noticable between 50-60mph with the worst of it being at 55. However it did lessen in severity the further i drove it but it didnt go away.

I also noticed it stops when you are coasting so that kinda kills the tire noise theory.

It seems to be coming from right under the cab or back. My gut reaction is a U joint but i never hear any clunking while changing gears.

It has a carrier bearing/2 piece drive shaft so im wondering if that could be it? But i always understood those got noisy while coasting and not under torque?

Or could it possibly be more serious like a pinion bearing? Ive never had one of those go out. But its not leaking from it.

I havent crawled under it yet cause its cold as shit and i dont drive it much but i need to get it fixed before spring when i use it the most.

Any input?

It appears you are on the correct path concerning the drive shaft or rear diff. From experience usually a bad u-joint with vibrate the vehicle when starting from a stop. That could also come from the carrier bearing. From your description that this occurs at a higher speed I'm inclined to believe the concern is with the rear differential.

 

[rusty ol ranger]

I had this with my 94 F250 a couple years back. I ended up replacing both U-joints and the center bearing. The bearing wasn't bad but the rubber isolator was pretty much toast. I still notice a drone but it helped a lot. You might have seen this already but I had found a post in another forum about vibration. It might help you narrow things down a bit. I saved it and it's copied below, good luck:



View attachment 87858

TRR—Tire and Wheel Radial Run out: Vehicle speed sensitive, mechanical vibration. The run out will not cause vibration below 20 mph (32 km/h).

WH—Wheel Hop: Vehicle speed sensitive, mechanical vibration. The wheel hop generates rapid up-down movement in the steering wheel. The vibration is most noticeable in the 20 - 40 mph (32 - 64km/h) range. The wheel hop will not cause vibration below 20 mph (32 km/h). Wheel hop is caused by a tire/wheel that has a radial run out of more than
0.045 of-an-inch (1.14 mm). If wheel run out is acceptable and combined run out cannot be reduced by repositioning
the tire on wheel, replace tire.

TB—Tire/Wheel Balance: Vehicle speed sensitive, mechanical vibration. Static tire/wheel unbalance will not cause vibration below 30 mph (46 km/h). Dynamic tire/wheel unbalance will not cause vibration below 40 mph (64 km/h).

TLR—Tire/Wheel Lateral run out: Vehicle speed sensitive, mechanical vibration. The run out will not cause vibration below 50 - 55 mph (80 - 88 km/h). Excessive lateral run out will also cause front-end shimmy.

TW—Tire Wear: Vehicle speed sensitive, audible vibration. Abnormal tire wear causes small vibration in the 30 - 55 mph (88 km/h) range. This will produce a whine noise at high speed. The whine will change to a growl noise when the speed is reduced.

W—Tire Waddle: Vehicle speed sensitive, mechanical vibration. Irregular tire uniformity can cause side-to-side motion during speeds up to 15 mph (24km/h). If the motion is excessive, identify the defective tire and replace it.

UAJ—Universal Joint (Drive Shaft) Angles: Torque/vehicle speed sensitive, mechanical/audible vibration.
Incorrect drive shaft angles cause mechanical vibration below 20 mph (32 km/h) and in the 70 mph (112 km/h) range. The incorrect angles can also produce an audible vibration in the 20 - 50 mph (32 -80 km/h) range. Caster adjustment could be required to correct the angles.

UJ—Universal Joints: Engine torque/vehicle speed sensitive, mechanical/audible vibration. If the U-joint is worn it will cause vibration with almost any vehicle speed/engine torque condition.

DSY—Drive Shaft and Yokes: Vehicle speed sensitive, mechanical/audible vibration. The condition will not cause vibration below 35 mph (56 km/h). Excessive run out, unbalance or dents and bends in the shaft will cause the vibration. Identify the actual cause and repair/replace as necessary.

WB—Wheel Bearings: Vehicle speed sensitive, mechanical/audible vibration. Loose wheel bearings cause shimmy-like vibration at 35 mph (56 km/h) and above. Worn bearings will also produce a growl noise at low vehicle speed and a whine noise at high vehicle speed. The wheel bearings must be adjusted or replaced, as applicable.

AN—Axle Noise: Engine torque/vehicle speed sensitive, mechanical/audible vibration. The axle will not cause mechanical vibration unless the axle shaft is bent. Worn or damaged axle pinion shaft or differential gears and bearings will cause noise. Replace the defective component(s) as necessary.

SSC—Suspension and Steering Components:
Vehicle speed sensitive, mechanical vibration. Worn suspension/steering components can cause mechanical vibration at speeds above 20 mph (32 km/h). Identify and repair or replace the defective component(s).

EA—Engine Driven Accessories: Engine speed sensitive, mechanical/audible vibration. Vibration can be caused by loose or broken A/C compressor, PS pump, water pump, generator or brackets, etc. Usually more noticeable when the transmission is shifted into the NEUTRAL position and the engine speed (rpm) increased. Inspect the engine driven accessories in the engine compartment. Repair/replace as necessary.

ADB—Accessory Drive Belts: Engine speed sensitive, audible vibration. Worn drive belts can cause a vibration that produces either a droning, fluttering or rumbling noise. Inspect the drive belt(s) and tighten/replace as necessary.

DEM—Damaged Engine or Transmission Support Mounts: Engine speed sensitive, mechanical/audible vibration. If a support mount is worn, noise or vibration will occur. Inspect the support mounts and repair/replace as necessary.

ES—Exhaust System: Engine speed sensitive, mechanical/audible vibration. If loose exhaust components contact the vehicle body they will cause noise and vibration. Inspect the exhaust system for loose, broken and mis-aligned components and repair/replace as necessary.

Thats a really awesome list. Thank you

It appears you are on the correct path concerning the drive shaft or rear diff. From experience usually a bad u-joint with vibrate the vehicle when starting from a stop. That could also come from the carrier bearing. From your description that this occurs at a higher speed I'm inclined to believe the concern is with the rear differential.

I was afraid of that.

 

[dvdswan]

@bilbo is that chart on the tech page? I think it would be a good info sheet to add if not.

 

[bilbo]

I have no idea, I found it on a different forum (FTE) a while back but it may be there too. I just copied it.

 

[rusty ol ranger]

Just an update on this if anyone cares or was curious...

Havent crawled underneath but today pulled out of driveway, changed gears and heard the telltale "clank" of a ujoint. Sounded pretty midship.