vibration

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

euclid

euclid

SILVER Star
Joined
May 15, 2002
Threads
327
Messages
6,063
Location
Jackson, MS
I had this vibration before the recent work. I was hopeing it would go away but it hasn't.

Truck starts vibrating at 40 mph. By 70 it's pretty loud and I cant see out of my rear view mirrors.

Tires are ballanced. Shop said they are cuped and might be the cause of the vibration. Swaped another set of tires on there and I still had the vibration. I might try a 3rd set just to make sure.

Rebuilt the drive shaft, shop said it is perfectly ballanced.
New rear axle FF swap that has new 3rds, gears and everything. Truck the parts came off of didn't vibrate.
Pinion angle is 1* different from transfer output. I turned the pinion up when I

Not in 4wd.
U bolts tight.
Shackles and spring pins tight
3rd member pinion output torqued properly.
No radial play in pinion.
No Excessive backlash in 3rd member.
No play in wheel bearings

Any other ideas? My last idea is that something in the t-case is coming apart, like a bearing race spinning or something like that.

Grasping at straws here.
 
You feel it in the seat of your pants or the steering wheel?
 
Mace said:
You feel it in the seat of your pants or the steering wheel?
Click to expand...

Nope, the whole truck. Not more in the steering wheel or seat. Whole thing. It drones in and out a bit at 70. Like wooommmwoooooooommmmmwoooooomm.
 
Greg,

Put it up on stands & then run the truck up to 70mph (DON'T GET UNDER IT & use good judgement.) you may be able to see the vibration... also pull the drive shafts & then rev it up in gear to 70mph... this will eliminate the t-case & trans if there is no vibration.

Does the vibration stop if you put the truck in neutral at speed or let off on the accelerator or shift gears? check that your lugs are all torqued propertly.

Try someone elses tires!
 
Greg,
Thats a tough one. Have you drained any fluid out of the tcase to check for bearing material?I start here because you say the vibration is whole truck. Does the Vib. change when you let off the gas?

I guess the first thing I would do is to check the tcase fluid for material.

Next I would jack up the front and rear and spin the tires individually and check for binding or roughness in the bearings. This may require you to pull the tires so you can turn by the rotors/drums.

If all that checks out pull the rear driveshaft and drive on the front to see if the noise changes or goes away. If it changes but is still there it may be the tcase. If its gone, well you know the answer to that one. Tcase could still have issues that are not being felt unless its loaded.

Torque converter? I would check bolts although they would make noise if loose.
 
Cory and Gary thanks for the hints. I've done some of that, but not everything. Ran it up to speed on stands and didn't see anything.

Does not go away in Neutral. It is speed sensitive not throttle sensitive. Bearings all feel good, none are very old. Maybe 30 K on front. I looked at the wheel bearings when I swaped the front axle out earlier this week, they look fine.

I'm gonna check the torque converter bolts and drive it in FWD and see what I find.
 
Sounds like a pretty serious vibration. Doesn't seem front end related, like balance, alignment or steering damper, or you'd notice more in the steering wheel. This leaves the rear drive line...
Rotating the pinion up can starve the pinion bearing of oil, leading to wear. Part of my vibration/noise problem was worn pinion bearing, along with worn transfer output bearing.
Pinion and transfer flanges should be parallel. This could be part of the problem.
Have you checked U-joints? Are the U-joints in phase? Worn/dry U-joints and out of phase U-joints can cause vibration.
(When the driveshaft is at an angle to the flange, the relative speeds of the shaft and flange change slightly through each rotation at the U-joint, which creates a pulse in the driveline. If the flanges are parallel and the U-joints are in phase, the pulse from one U-joint is cancelled by the pulse from the joint at the opposite end of the driveshaft. If they are out of phase or not parallel, the damping effect is not equal, hence a vibration.)
Are the tires round? Out of Round tires can still be in balance, but cause vibration at speed. You say you swapped tires, but it still vibrates. Did it change at all?
Does it do it on throttle, off throttle, coasting, or all? Driveline noises can be hell to track down. Good luck.
 
Drive shaft was the 2nd thing to check. It has ben done and redone by the best shop in town. We have tried 4 different versions/brands of U-joints and even re-tubed the shaft. No luck.

I should have time tomorrow to pull the DS and see what happens.
 
Is this the same vibration that we felt on the test drive after we finished the front? It was doing it a 5mph. Right?
 
Bodean said:
Is this the same vibration that we felt on the test drive after we finished the front? It was doing it a 5mph. Right?
Click to expand...

Nope, that's gone. This is the vibration that was there before I started any of the driveline work and is still there.
 
yep

:confused:
euclid said:
Nope, that's gone. This is the vibration that was there before I started any of the driveline work and is still there.
Click to expand...
:confused:

i am guesing the transfer case output shaft?
 
Try checking the centre bearing on the rear tail shaft this can cause a serious vibration through the hole car. Even large trucks can feel the vibration when the centre bearing is worn out.
 
This is an amazing thread! I'm experiencing the exact same thing in my 60 after I had my H55F installed. Hopefully there is more input in this thread. I cannot figure out where the vibration is comming from.
 
I had the same problem before...it was speed senstive anyway. It turned out to be that my pinion angle was off. Are you sure yours is correct? Keep the angles stock unless you are running a CV.
 
renstimp said:
Try checking the centre bearing on the rear tail shaft this can cause a serious vibration through the hole car. Even large trucks can feel the vibration when the centre bearing is worn out.
Click to expand...

Tailshaft?

lowtideride said:
I had the same problem before...it was speed senstive anyway. It turned out to be that my pinion angle was off. Are you sure yours is correct? Keep the angles stock unless you are running a CV.
Click to expand...

Pinion angle is perfect. I turned it up a tiny bit when I did the axle swap to account for the shackle lift. It is 1* different with no load on the truck.
 
I did the same and ended up with a vibration. ended up shimming it back down with a 2 degree shim...no vibrations to date.
 
lowtideride said:
I did the same and ended up with a vibration. ended up shimming it back down with a 2 degree shim...no vibrations to date.
Click to expand...

Good info, but I had this vibration before the rear axle changes so I gotta think it isn't the pinion angle.
 
ahh, good point. I just noticed a thread in hardcore about your pinion and thought it was worth another check. Um, I will blue sky it some more but if your figure it let us know.
 
OK, update.

With no rear driveshaft, in 2WD I can run the truck to 80 with no vibration.
Front wheel drive, I get a different vibration than before.
Normally it is a woom woom type vibration that ossilates and starts at 40 or so and I can't drive through it. In Front WD with no rear driveshaft I get a heavy vibration that starts at 25 and goes away at around 40. No vibration at higher speeds.

I'm thinking driveshaft again. I'm gonna give the local driveshaft shop one more shot at it, failing that I'm gonna find somewhere else to get it fixed.

Whatchallthink?
 
You must log in or register to reply here.

Users who are viewing this thread

Total: 1 (members: 0, guests: 1)

Share this page

Back
Top Bottom